# Scotch Type Marine Boiler



## doubletop (May 30, 2010)

It's time for another boiler now that my last engine is finished. http://www.homemodelenginemachinist.com/index.php?topic=9412.0

Its a marine engine so needs a marine boiler. I've done a vertical boiler so this next one has to be horizontal. I've recently been reading K N Harris "Model Boilers and Boilermaking" and it has examples of a Scotch Marine boiler and the Inglis variant. The trouble is the plans require something like 6" tube. I've got 3" tube so it's going to be that. 

The plan is to fire it with LPG gas (propane/butane) and a through flue burner much like SandyC's plans for 3.5" burner http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item175 however the burner flue is going to be 1" tube as I'm only using a 3" main tube. So the first thing was to try out a burner design and see if it would work enclosed in a length of pipe. First attempt was a non starter. I based it on a small Sievert burner which worked well when poked up the pipe. But my copy was a disaster and flashed back as soon as you looked at it.












Next was something based on this old torch that was lying in the junk box. It has a #10 jet which will do fine






So I set about copying the parts. Which is basically a hole for the gas to come though and mix with the air.






All the parts just push fit together for now






Then light it up. It needed a bit of adjusting of the size of the second set of air holes but it fired OK just by lighting the end of the tube. To allow for a bit of tuning I have already made an adjusting sleeve for the air flow ready for some bigger air holes and hopefully to deal with the "pulse jet" noises it makes when the gas is turned up.

[ame=http://www.youtube.com/watch?v=LIvCLxzY0I4]http://www.youtube.com/watch?v=LIvCLxzY0I4[/ame]

There may be an issue with flashback when it all gets a bit hot but successful enough for now to proceed with the boiler design............


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## doubletop (May 30, 2010)

So that was yesterday. Today I made a start on the major components and sketched out a design. I make no appologies for a bit of plagiarism as some of the bits come from the SandyC designs. The first draft of my design can be found here http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item263

It remains to be seen it it works but I won't find out unless I build it, so here goes....

Cut out the plates






First phase of anneal/bash/anneal cycle






Four plates at one point in the cycle






Finishing the edges in the lathe






Then I realized I now had a new mill so try that instead. Much better





Finishing the ends of the main tube in the lathe






After an hour in the pickle






I just love that clean pink finish after the pickle. You'll see there are now 5 plates when I need 4. I had a spare one after may last boiler cock up. No doubt there be another cock up at some point so the extra plate may as well come on the journey.

That's going to be it until next weekend. People have decided they are willing to pay me for work so I'd better not disappoint them

Pete


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## doubletop (Jun 6, 2010)

Had a chat this week with our boiler inspector and he was OK in principal with my plans so this weekend I set about drilling the end plates and boiler barrel.

I dont have a step drill so I did the holes in the end plates for the burner tube in the 4 jaw chuck with the boring bar.

Setting the centralizing the hole using a center between the punched centre point and the tailstock.






Boring the holes






Trouble is my lathe is too small so I couldnt get the holes for the two return flues centered on the 4 jaw so over to the mill and the boring head.






The finished plates; The square hole is for access to the super heater and will have a door on it eventually.






On to the boiler barrel. That was relatively easy. Like my last boiler I am going to use rivets to keep the plates aligned while I solder them up.

When it came to the hole for the steam dome the boring head wasn't going to work as the head hit the curvature of the barrel and tried to move it on each rotation. Many ways of skinning the cat and I found I had a ¾ slot drill that would to the job.






All the parts ready after a while in the pickle.






Loose assembled boiler











This boiler has a central flue and rather than the smoke stack being at the opposite end the Scotch boiler has the flue at the burner end so the got gasses from the burner go down the main burner tube to a cavity at the opposite end (where the superheater will be) and then fold back down secondary flues (I have 2 on this boiler) and into a 'smoke box' at the burner end. You'll see two matching sets holes in the both end plates. These are for the water gauge. The intention is to have long bushes that extend from the main end plate through the smoke box and out to the secondary end plate. Check the outline drawings http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item263

Thats it for this week I may get the main burner flue cross pipes soldered up but Im waiting for the bronze for my bushes to arrive and Ill do those next weekend. 

Pete


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## Diversion900 (Jun 6, 2010)

Looking good so far.

I am looking into building an Inglis variation, so I will be watching with interest.

What size is the tube you are using ?

I have a piece of 4" Diam. copper I am thinking of using for mine, but most of the pictures I have found use 3".

Cheers, Neil


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## doubletop (Jun 6, 2010)

Neil

I wanted a basic marine boiler and found the K N Harris book "Model Boilers and Boiler Making". From what I could establish his sketches were in the area of 6" dia. I had 3" tube and that's what I had and wanted to use. (also in some jurisdictions there are boiler regs considerations going above 3")

I looked at the commercial offerings and had done the SandyC 3" vertical so thought I'd base this one on his design, pinching the basic components. You'll see the sketch I've posted and progress so far, I'm using 16gauge for the body and 18 or 20 gauge for the tubes (there's a bit of margin there). I had a chat with the club boiler certifier last week and he thought the safety margins will be OK as he proposed to use 16 rather than 8 as the safety factor for the flue tube calcs as they are under compression and not tension, but still OK. Also this boiler is for 50psi max as its for my double acting oscillator so too much pressure is not required.

So this is very much what you see is what you get, a design/build as you go project. Maybe it will work OK, maybe not. However, the defining moment was the burner as I have realized that is critical in the success of any boiler. Once I had got the burner working doing the boiler was to some degree secondary.

If you are doing an Inglis are you planning it to be detailed down to three sets of 'folded' flues or a basic representation? How do you plan to fire it. No doubt you know this but if you have a piece of 4" copper the thickness and planned operating pressure are key factors on deciding if its suitable for your planned boiler. 

Welcome on the journey

Pete


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## Diversion900 (Jun 7, 2010)

G'day pete,
 I am still in the planning stages at present but I have planned on a ceramic gas fired tube, with a slightly smaller return tube, maybe with cross tubes ?, then back the other way through some smaller tubes either side of the second one.

Most of it is still in my head at present, but I have most of the components at hand, I just have to get hold of some Phospher Bronze.

I am not in any club yet so don't know of any restictions on size, and I can always make a smaller one to satisfy club rules at a later date.

Its just that I would dearly love to have a large-ish boiler at my disposal to run anything I throw at it, and my piece of 4" is just begging to be used ;D.

Cheers, Neil


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## doubletop (Jun 8, 2010)

Neil

Sounds like you are in the same place I was. I couldn't find plans for what I wanted so rather than pitch in and find I couldn't fire it, I did the burner first. Once I'd got burner sorted I then turned to the sketches of the boiler. 

If you want a burner design for a ceramic,horizontal in tube the plans for one are here http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item175 

However, number one consideration for now is what pressure are you planning to work at and how thick is your 4" tube. I'm no expert but have established that for a drawn copper tube under expansive pressure (not compression) and having a safety factor of 8 (from what I can establish the accepted safety factor) is given by:

_Thickness = max working pressure (psi) x inside diameter of tube (inches) / 2 x 3125 . If your tube is thicker than the result you are in business. _

On this site somewhere are the calcs for the SandyC 3" vertical boiler but I can't find them. One point of debate is the calcs for the internal tubes. The internal tubes that are under compression and they can collapse a lot more easily under pressure. Sandy used the same safety factor of 8. My club boiler tester has proposed a factor of 16 which really means make these tubes twice as thick as the calculation, or half the max working pressure. As all these posts will tell you boilers are dangerous don't underestimate what you are doing.

Like you I also need bronze for the bushes and am on hold until MBM deliver it. 

Pete


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## Maryak (Jun 8, 2010)

Hi guys,

An extract from an old post of Sandy C's on copper tube wall thickness.

T = (PxD / 2xS + P) + 0.005 x D

And for pressure this would be: -
P = S [2xT 0.01 x D / D - (T - 0.005 x D)]

Where S = Maximum allowable stress value of the design material at design
temperature.

For copper @ temperatures below 450deg F it is reasonable/acceptable to use: -
S = Tensile Strength / 3.5. (Above this temperature, then reference to stress tables
would be required).

For copper with an 8 times safety factor this would amount to: -
S = 3125 / 3.5 = 892.857psi.

Also in this case D = Outside dia.

This is in fact a much-simplified version of the formulae, however, for the purposes of
designing of model boilers, operating at relatively low pressure and temperatures and
which are using silver soldered jointing methods, it is perfectly satisfactory/adequate.

Hope this helps

Best Regards
Bob


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## Diversion900 (Jun 9, 2010)

Thanks guys

I will do some calculations on the tube I have to see if it is worthwhile using.

I was thinking maybe 50 or 75lb but I wll see what the fugures say.

Cheers, Neil


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## cfellows (Jun 9, 2010)

Pete, what is the purpose of the two return flues?

Thx... Chuck


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## doubletop (Jun 10, 2010)

Chuck

Its a bit of artistic licence on the original design of the full size boilers. I am basing my design on the outline of the boilers in the the KN Harris book. In that book there are photographs of a model boiler similar to the one I'm doing. I'm making use of the info available and building it and seeing what happens without paying much attention to the detail of the theory.

Without going back into book and paraphrasing it my take is:

These boilers are compact and all the functional parts are at one end so don't need access to "the other end". In the full size situation they would install two back to back. _The access door at the back end of my design has no functional use and probably would be detrimental to the thermo dynamics but what the..?_

The folded design allows for all the heat to be exttacted from the heat source as it travels first in one direction and then the other through the boiler. Many smaller tubes have a greater surface area than one tubes allow more heat transfer into the boiler. OK two is only just more than one.

The Inglis version extends this approach and there are three sets of tubes getting progressively smaller on each 'fold'. That's what Neil is planning to make. Why do they need to be smaller on each fold? From my point of view it feels right but the theoreticians can probably give us chapter an verse.

So the idea is a compact marine boiler that can be installed in a small space and extracts as much heat as possible from the heat source. As we know the vertical center flue boiler is very inefficient, this type should be somewhat better. Can I prove it? Probably not but its going to be fun doing it anyway.

Hope that helps?

Now MBM where is that bronze?? The weekend is coming up fast.

Pete


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## doubletop (Jun 10, 2010)

Update to the drawings

http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item269

Pete


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## cfellows (Jun 10, 2010)

OK, I get it. The burner gases go through the large tube into a closed chamber on the other end of the boiler then come back through the return tubes to be exhaused on the same end as the burner. Very clever!

Chuck


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## doubletop (Jun 11, 2010)

Chuck

That's it; and the Inglis does three passes and then exhausts at the 'conventional' end. We'll let Neil show us that when he gets his build going.

Bronze hasn't arrived for whatever reason, no bushes this weekend so no soldering, or not much anyway. I'll do what I can on some other bits.

Pete


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## Diversion900 (Jun 12, 2010)

Sorry to hijack your post again pete, but I'm a little confused with the figures I came up with..... ?

The Copper tube I have is in fact a metric 4" diam. 16SWG 
which is actually 101.5mm OD and wall thickness is 1.5mm
converted to inches makes it 3.996" OD wall thicness 0.059055"

If I use your formula I get a max pressure around 95psi which works out fine for me,

but using the other formula from Bob I get about 17psi ?

I am in need of some expert advice here I think. 
Maybe we should move this question to the Q & A section so we don't get too far off topic with your build.


Cheers, Neil


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## Maryak (Jun 12, 2010)

Neil,

I may have confused the issue here :-[

The formula for the boiler shell is P=(2T x t)/D so for your example

P = (2 x 0.059" x 3125)/4

P = 368.75/4

P = 92 psi.

The formula I quoted in my previous post is for the boiler tubes i.e. furnace tubes/return tubes.

e.g. if your flue tube is 1.5" Dia and using 1.644 as the OD

T = (P x D / 2S + P) + 0.005D

T = (92 x 1.644/ 2 x 893 + 92) + 0.005*1.644

T = (151.248/1878) + 0.0082

T = 0.089"

As 1.5" copper pipe has a standard wall thickness of 0.072" this is below the thickness required for a boiler at 92 psi. so use high pressure copper pipe, or reduce the boiler pressure, or use a smaller flue tube etc.

similar for the return tubes using 0.5" copper pipe and using 0.598 as the OD

T = (92 x 0.598/2 x 893 + 92) + 0.005*0.598

T = (55.016/1878) + 0.003

T = 0.032"

As 0.5" copper pipe has a standard wall thickness of 0.049 then this is OK for a boiler at 92 psi.

I hope this helps and sorry if I confused you previously.

Best Regards
Bob


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## doubletop (Jun 13, 2010)

Bob

Thanks for this it has helped me confirm the working pressure for flue tubes for this boiler. I had to add some extra brackets in your formula to get the same results as you.

T = (92 x 1.644/ (2 x 893) + 92) + (0.005*1.644)

I am using 1" tube for the main flue OD = 1.078 and wall thickness of 0.036" ignoring the cross tubes the calculation for 92psi comes out as requiring a wall thickness of 0.058" however this boiler is for my small engine so don't plan to go above 50psi and for 50psi 0.034" is required.

The return flues are OD .0579 so all is well there.

Pete


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## Diversion900 (Jun 13, 2010)

Thanks guys, I feel a bit happier now, I didn't think my maths was that bad. ;D

I had planned on a max pressure of 50 to 75psi as previously stated, so with these figures I could still work on a 75 psi working pressure, providing I use a pump and a good burner to keep up steam.

Looks like my 4" tube will do the trick after all. 

Cheers, Neil


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## Diversion900 (Jun 13, 2010)

To satisfy my curiosity, and maybe some others out there as well.....

Does this mean that when testing, we shouldn't go past 92psi, thus having a working pressure of half this amount, being 46psi. ?

Or am I stretching the safety thing too far ?

Cheers, Neil


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## Maryak (Jun 13, 2010)

doubletop  said:
			
		

> Bob
> 
> Thanks for this it has helped me confirm the working pressure for flue tubes for this boiler. I had to add some extra brackets in your formula to get the same results as you.
> 
> T = (92 x 1.644/ (2 x 893) + 92) + (0.005*1.644)



Well of course you did. : If I was an artillery man I would have bracketed it correctly but being an old steam plumber scratch.gif my apologies for the unbracketed assumption. 

Best Regards
Bob


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## Maryak (Jun 13, 2010)

Neil,

By testing to 2 x WP you still have a safety factor of 4 on the initial test and 5 1/3 on all subsequent tests. Also hydrostatic testing is carried out cold.

The calcs are good to go working pressure calcs for temperatures up to 4500 F which is a bit over 400 psi but..................thinking on the side of safety is *NEVER* a bad thing.

Best Regards
Bob


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## Diversion900 (Jun 13, 2010)

;DThanks Bob, 

now I get it, the 8 X safety factor IS built into the calculations already.

So if I set myself a max working pressure of 75psi I can safely test to 150psi on a cold hydro test..... :bow:


Cheers,Neil


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## doubletop (Jun 13, 2010)

Thanks for this guys we now all know where we are on this. The internal tubes calc wasn't something I wasn't familiar with as the calcs I'd done previous were based on the Sandy'C example which my boiler tester had told me used the incorrect formula. He was going to give me the correct formula but I have it now.

Neil, I would expect your next challenge will be how to heat your boiler. I'm using standard 1" tube for the main flue with cross tubes which act like stays. You'll probably need something bigger but as you can see from Bobs calcs standard 1.5" tube isn't up to 92psi.

So next question Bob. Cross tubes act like stays so does their inclusion affect the safety margin value used in the formula?

Pete


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## doubletop (Jun 13, 2010)

This weekends activities. The bronze didn't turn up so I did a few of the other bits and bobs. The main mounting brackets and the boiler access door.

Fly cutting the 1.5" radius for the mounting brackets with a home made fly cutter







The finished brackets with relief cut with a T slot cutter so they'll match the similar rails I did for the engine.






Rounding off the ends of the hinges on the rotary table






All the boiler door parts ready for fitting to the end plate






Loosely fitted together to give an idea how it will all look.






Just a bit of finishing required on all these parts. The current V3 drawings doesn't have the door details yet. I need to amend V4 as what I drew and what I built had some subtle differences. I may re-post V4 later in the week.

Pete


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## Diversion900 (Jun 13, 2010)

Lookin' good Pete


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## doubletop (Jun 13, 2010)

Thanks Neil

Hopefully I can get the bushes made next weekend and then the soldering underway. That's when things went down hill a bit last time but I'm hoping for better results now that I have had more practice. The whole point being the more I do the better I should get. To quote Bogs strap line_ "If you don't try it, you will never know if you can do it."_

Pete


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## Maryak (Jun 13, 2010)

doubletop  said:
			
		

> So next question Bob. Cross tubes act like stays so does their inclusion affect the safety margin value used in the formula?
> 
> Pete



Personally, I would use the shell calc for the cross tubes because the pressure is from the inside to the outside. I agree with you that they also act like stays for the main furnace/flue tube, so I don't believe that the safety factor is affected downwards. Using the standard formulae will, I believe, give adequate safety, acceptable to our codes here in Oz.

Hope this helps

Best Regards
Bob


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## doubletop (Jun 14, 2010)

Bob

I understand your reply and re-read my question. I was suggesting that with the inclusion of cross tubes acting as stays to the larger burner tube it would allow a reduction of the safety margin used in the calculation (a value greater than 893) and hence it can be used at a higher pressure?

That then leads to another question. There seems to be no consideration to the length of the tube under pressure. I would have thought that 2 meters of tube under compression would be more susceptible to collapse than say 2cm. Or lets say a tube that has a length less than its diameter is less susceptible to collapse than a tube with a length of many multiples of its diameter?

On another subject bronze for the bushes arrived today. That took a week to come by NZ post from Auckland. A book I ordered from Amazon UK to 2 days to get to NZ.


Pete


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## Diversion900 (Jun 14, 2010)

;D :big:Sounds like your NZ "snail mail" is very similar to ours here in Oz Pete.


Cheers, Neil


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## kvom (Jun 14, 2010)

An earlier post asked while a folded flue should be smaller on each fold.

As the flue gas travels it gives up heat. Thus there is less energy to transmit the further along it goes. A smaller tube will extract a proportionally small amount of the reduced available heat energy and thus be able to reach a higher temperature.


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## Maryak (Jun 14, 2010)

doubletop  said:
			
		

> I understand your reply and re-read my question. I was suggesting that with the inclusion of cross tubes acting as stays to the larger burner tube it would allow a reduction of the safety margin used in the calculation (a value greater than 893) and hence it can be used at a higher pressure?



To be honest I have not been asked this before and my pressure vessel certification to date has been for 12" : 1ft vessels. IMHO you are correct. This now comes down to an agreement between you and your local testing authority.



> That then leads to another question. There seems to be no consideration to the length of the tube under pressure. I would have thought that 2 meters of tube under compression would be more susceptible to collapse than say 2cm. Or lets say a tube that has a length less than its diameter is less susceptible to collapse than a tube with a length of many multiples of its diameter?



To the best of my knowledge stress is not a function of length. The only reference, with respect to your question, I can find, is in the use of stays where the length and type of the stay has, in most instances, a length limit as a function of diameter, e.g. a 1/4" stay would have a maximum length of 7 1/2"

Finally a full size Marine return fire tube, (Scotch), boiler has a diameter greater than its' length of the order of 16:9, (Just like a new TV :).

I hope this helps.

Best Regards
Bob


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## Diversion900 (Jun 14, 2010)

So what you're saying Bob is that the proportions that Pete is using here, being 3"X5", and my plan to use 4"X6" is in fact A$$ about 'cos we are long and skinny instead of short 'n fat.  :big:

Cheers, Neil


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## Maryak (Jun 14, 2010)

Diversion900  said:
			
		

> So what you're saying Bob is that the proportions that Pete is using here, being 3"X5", and my plan to use 4"X6" is in fact A$$ about 'cos we are long and skinny instead of short 'n fat. :big:
> 
> Cheers, Neil



I guess I am but as long as it's safe what does it matter. ;D 

About a year ago, I priced some 6" and 8" dia new copper pipe. Minimum length was 3 ft. they came out at $800 and $1000 each 
	

	
	
		
		

		
		
	


	










 so what is on hand is a great option yes ???

Best Regards
Bob


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## Diversion900 (Jun 14, 2010)

I can sympathize with that.......

I started out looking for 6" diam. but ran into similar brick walls (like prices and quantity).  Trying to get someone to sell you a 6" length of 6 to 8" pipe is near impossible around my neck of the woods. 

My local scrap yard came to the rescue with a 12" piece of 4" and I was stoked.....

Hence the project begins.  :big:


Cheers, Neil


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## doubletop (Jun 15, 2010)

Maryak  said:
			
		

> About a year ago, I priced some 6" and 8" dia new copper pipe. Minimum length was 3 ft. they came out at $800 and $1000 each
> 
> Best Regards
> Bob



Yes been there; for the 3" tube they wanted $280 for a meter. Scrap yard sold me some at $11/kilo (it varies). From the supplier catalogue 80mm = 3.12kg/mtr, 100mm= 4.69kg/mtr and 150mm = 7.86kg/mtr 

So 3" tube it is and the aspect ratio has to go out the window. However, the KN Harris book has a picture of long and skinny version and that's what kicked me off. I can now build a long and skinny boat rather than a short fat one. 

Neil so you are on your way then......???

Pete


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## Diversion900 (Jun 15, 2010)

Still have to get the PB, and some 1.5 and 1" tube.

The figures are pointing at these sizes, with the 1.5" tube requiring a reduction in max working pressure to 73psi, which is close enough for me.

I just have to put it all on paper to see how many small tubes I can fit on the third flu set.

This one is definately not a project to rush into 

Cheers, Neil


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## Blogwitch (Jun 15, 2010)

Hey Lads,

What you are forgetting is what you are going to be running with these small boilers.

You are not powering the Titanic, but a small steam engine, most probably for display or in say a model boat. From my experiences in model boats that are steam powered, you will most probably be running somewhere between 15 & 25 psi, so a boiler with a working pressure of 50 psi should be more than ample. Small engines you will find, don't like high pressures when running on steam, they run in a totally different way than when run on air.

By going down on your pressure requirements should relieve a lot of the worry over your material selection.

I found that staying on the lower pressure scales (I had mine with usually a max working pressure of 45 psi), I could use generally available plumbing sizes of copper tubing for making boilers for myself and friends, and the scrap yard got a fair amount of the 75mm & 100mm diameters in as offcuts, because most public buildings use copper instead of plastic piping for drainage because of the longevity of use required.

If you still want to go the higher pressure route, maybe a simplified yarrow boiler, with their smaller diameters of main boiler tubes (3 off) would put it within your price range. I have never built one, but I have seen model ones, and they can reach high pressures very quickly and still maintain that pressure easily.

http://en.wikipedia.org/wiki/User:Andy_Dingley/My_created_pages/Yarrow_boiler


Bogs


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## doubletop (Jun 15, 2010)

John

I hope all is well?

I've had your sage like advice in mind during this build. This boiler is for the French marine engine I have just completed and 50psi has always been the max intended. As you'll recall from the video it runs really well on 20psi and even starts and reverses under no load at 5 psi (or maybe less). And I have the fixed pressure reducer already in place on the steam line of the engine.

The discussion with Bob and Neil was about establishing the suitability of Neils 4" pipe for a similar boiler.Somehow that discussion ended up at 92psi. but was interesting and informative.

I did think of doing a Yarrow at one point, as KN Harris has one in his book. However, I came across a small book in the archive of the public library circa 1949 'Flash Steam" its about flash boilers for model speed boats from around the 30's. It has some intriguing designs including one in particular made from a continuous length of 1/4" copper tube wrapped in multiple figure 8's much like a coil of rope wound on 2 pegs. They have the disadvantage of needing a continuous feed engine driven water pump but an interesting challenge. Maybe something for the future.

Regards

Pete


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## Diversion900 (Jun 15, 2010)

Thanks for the advice John, but my theory is that just because you have the capability of high pressure, doesn't mean you have to use it.

I feel a V8 ticking over at low revs doing the job easily is better than a 4 Cylindar running flat out to do the same job.

I have made a few small pot boilers before, and this one is going to be more a challenge and workhorse for maybe multiple engines at the same time.

I also have on my "to do" list, a larger working engine that may require this type of pressure.

I just liked he layout of this style of boiler and thought I would give it a go, its just coincidance that Pete and I seem to be on a similar build in the same timeframe.

Keep the advice coming guys, every little bit helps.

Cheers, Neil


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## Blogwitch (Jun 15, 2010)

Pete and Neil,

I wasn't trying to say you were doing anything wrong at all, I was just giving a little insight that very heavy gauges in copper are not always required if you really want to make a small boiler. More so in the UK, where we have the 3bar/litre rule, where if your boiler is within it, very little rules and regulations apply to it's build and material thicknesses. More of a common sense build, rather than a 'done to the rules and regulations' one.

As I said, I have seen model 'Yarrow' boilers in operation, and I was astounded at the speed they got up to their high working pressure. From cold, just a couple of minutes.

Flash steam is having a bit of a resurrection here in the UK, and some are using electronics for the control of burners and water injection.

Have a Google search for 'Model Boat Mayhem' and when you open it up, search the site for 'flash steam'. There are people doing wonderful things with it on there.


John


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## Diversion900 (Jun 15, 2010)

Definately no offence taken at all John, it takes a lot to wind me up :big:

Anyway back to the build.

Cheers, Neil


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## doubletop (Jun 16, 2010)

Bogstandard  said:
			
		

> Flash steam is having a bit of a resurrection here in the UK, and some are using electronics for the control of burners and water injection.
> 
> Have a Google search for 'Model Boat Mayhem' and when you open it up, search the site for 'flash steam'. There are people doing wonderful things with it on there.
> 
> ...



Now you've got me interested I was only thinking the other day how I could marry up this new hobby with my electronics/electrical eng/IT background. Done a fair bit with micro controllers and have the facilities to make small PCB's so it would be a good match. I've registered on the site but can't see some of the pics. I'll wait until I get authorised.

Downside, it looks like a bit more time on the PC and less in the workshop.

Pete


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## fcheslop (Jun 16, 2010)

Hi Pete you need to be logged in to see the pics on that forum.Are you planning to fit electronic boiler level control and attenuator valve for flame control .Peter Arnold and Malcolm Beak wrote some good articles on these a few years ago and they work well although the electronics could now probably replaced with a programmable pic .Theres some good ideas as Bogs mentions especially on my favourite flash steam although its been a long time since I built any as Bob Kirtly took the speed record over 100mph I believe and i was struggling to get over70 so gave up :big:Nice looking boiler.
regards frazer


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## doubletop (Jun 17, 2010)

Frazer

Got authorized and access to the pictures and flashtwo's thread. Extremely interesting although he seems to have gone off on another tack with a steam jetboat. I've PM'd him to see if I can get more details. I've no intention of doing any electronic controls on this boiler but its an idea for the future.

100mph is amazing, the record in the book I had was around 35mph in 1949 so I'd be pretty pleased with myself with if I'd got anywhere near 70mph. Perhaps we should start a flash steam thread under the boilers topic??

OK guys flash steam discussion in this thread is now closed and back to the job in hand. Which for me is making bushes. Did two last night after work and its Coro night here so an opportunity to escape tonight and do some more.

Pete


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## fcheslop (Jun 17, 2010)

Hi Pete,I was just curiouse as when I design/build my small boilers I'm now in the habit of having a couple of spare bushes fitted to the boiler just in case I need to fit any other fittings usually one at the top for say a level probe and another on one of the end caps.Saves having to T up at a later date as I always seem to forget something but that's typical of me.Enjoying the build as iv never built this type of boiler but starting to be tempted .Have you seen P Arnots wet back centre flue boiler its a good steamer iv built a couple for boats and they cope well with your oscillator engine.Just one question as I don't know will you have to use forced draught on the boiler?
regards Frazer


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## doubletop (Jun 17, 2010)

Frazer 

I've got a couple of spare bushes. One on the steam dome and one on the top. The one on top is for the check valve if I ever get to run a water pump on it. Maybe it should have been on the side, but its on top. Truth be known this engine and boiler is highly unlikely to see a boat, but you never know. I'll probably get it fired up tune it up a bit, mount it on a nice piece of hardwood for display and move on to my next project. I really want to get to doing a decent twin cylinder with steam chests and make good job of it. The things I've done over the past months have really been a sort of self enforced apprenticeship to see if I could make something half decent, with the aim of working up to a real project. 

I haven't seen P Arnots boiler. As you've probably realized I have been grabbing every bit of boiler info I can and pooling it to come up with this. But I haven't seen that particular boiler as far as I can tell.

I got out into the shop tonight and made the two extended bushes for the water gauge that go through the smoke box. A redraw is in order as I didn't do them to the plans but that can wait until the weekend. Anyway I was busy turning away thinking about things and it crossed my mind, _"These bushes go through the smoke box, will they act like superheaters for the water going to the water gauge and I'll end up with some strange effects on the indicated water level?_" The only way I'll know is carry on and see what happens.

Anyway that's it for now 10:45pm in NZ and work tomorrow

Pete


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## fcheslop (Jun 17, 2010)

Isn't it strange what goes through our minds when machining as to the level gauge sorry I don't know how it will be affected .Thanks for the reply the questions are not meant as criticism of the design but just to clarify some points of interest as Iv been looking to build a scale model of Windermere Steamer and the the available boiler space is very small .
regards Frazer


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## Maryak (Jun 17, 2010)

doubletop  said:
			
		

> These bushes go through the smoke box, will they act like superheaters for the water going to the water gauge and I'll end up with some strange effects on the indicated water level? The only way I'll know is carry on and see what happens.
> 
> Pete



Pete,

My guess is that if anything you will get a sightly higher water reading in the glass compared to the actual level in the boiler. With the sizes and distances involved I doubt it will be of any real concern.

Hope this helps

Best Regards
Bob


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## doubletop (Jun 18, 2010)

Bob

Thanks for the advice its encouraging to know I should be on the right side of "will it work?"

So we will see in due course; the weekend lies ahead so some more progress should be made and I may even get around to soldering a few parts together.

Pete


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## doubletop (Jun 18, 2010)

fcheslop  said:
			
		

> Thanks for the reply the questions are not meant as criticism of the design but just to clarify some points of interest as Iv been looking to build a scale model of Windermere Steamer and the the available boiler space is very small .
> regards Frazer



Frazer

Sorry missed your post; I didn't even consider your observation as criticism I took it more as a checkpoint "what have I missed". The great thing about this forum is everybody looking over your shoulder pointing you in the right direction. It would probably be impossible to quantify the advice we recieve here. How many books, copies of your favorite model engineering mag, $ in wasted materials, time in the library would it have taken compared to an overnight response? _ (better shut up otherwise someone will take note, the site will get sold and we'll be paying a subscription before we know it)_

Pete


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## fcheslop (Jun 18, 2010)

Thanks Pete,cannot agree more the way members give up time and advice to others is fantastic and the wealth of knowledge absolutely remarkable.I really think that it is an inspiring site I know I'm a lot more careful about the finish than I used to be due to the bling master :big:
regards and best wishes Frazer


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## doubletop (Jun 19, 2010)

Today I manged to finish all the bushes







Push fit on the body to see what they'll look like






All the parts now made and ready to start assembly






So its now all in the pickle getting a good soak, ready to make a start tomorrow.

Pete


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## Blogwitch (Jun 19, 2010)

You have done a fantastic job up to now Pete, :bow: now comes the anal sphincter twitch, sticking it all together, and no, super glue won't do it. scratch.gif

Just like machining, get your stage process worked out first, :noidea: and make sure you have enough heat available, in fact err on the side of too much if you can. There is nothing worse than having a soldering job freeze up on you.

Good luck with your next expedition.

John


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## doubletop (Jun 19, 2010)

Thanks John

As you well know we've been here before. However this time I know what to expect. In fact I've already done the cross pipes in the main burner tube and its back in the pickle ready for inspection in the morning. I'll go over it with a fine tooth comb. You don't get a second chance with that bit, if it leaks in the pressure test the whole think is scrap as you can't get it out again to fix it.

BTW been on to "flashtwo" on the MB Mayhem site and he's given me a few more details of his micro controlled flash setup. So I have few thoughts there and started sketching some ideas. 

Also you got a mention in one of the recent posts about restarting a single cylinder engine and reference some "jiggler" (or some-such) gizmo. You may want to take a look.

All the best.

Pete


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## Blogwitch (Jun 19, 2010)

Pete,

I can't view that post.

I was banned from that site when I told the idiot who runs it where to stick his rules and regulations.

I am quite capable of reading and understanding rules, and he started to quote a few things to a couple of us quite unnecessarily, so hopefully he has now got a rules & regs shaped ar*****e.

His loss, not mine, because I was one of the resident engineering helper outerers on there. Anyone with an engineering problem usually got it solved, usually by me giving instructions on how to do it, or making the part for them.

The lads on there now correspond by email to me if they have a problem.

John


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## tel (Jun 19, 2010)

Pete, the best way to deal with that tube with its cross tubes is to butt solder a couple of flat tubes on the ends (soft solder will do) and pressure test it _before_ it goes into the assembly.


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## Diversion900 (Jun 19, 2010)

Lookin' good Pete.

Best of luck with the soldering.

Cheers, Neil


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## tel (Jun 19, 2010)

From E.L.Yallop's article on the Monarch Steam Plant













View attachment crosstubes3.jpg


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## doubletop (Jun 19, 2010)

Bogstandard  said:
			
		

> I am quite capable of reading and understanding rules, and he started to quote a few things to a couple of us quite unnecessarily, so hopefully he has now got a rules & regs shaped ar*****e.



John

As you say, their loss. I sense you have little time for "jobsworths".

Neil

Thanks I'm feeling good about it this time round




			
				tel  said:
			
		

> Pete, the best way to deal with that tube with its cross tubes is to butt solder a couple of flat tubes on the ends (soft solder will do) and pressure test it _before_ it goes into the assembly.



Tel

Great idea and I'll do just that, thanks.

Yet another helpful gem from this forum

Pete


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## fcheslop (Jun 19, 2010)

Pete, On my last centre flue boiler I tested the flue by blanking the end with demijohn rubber plugs .Drilled a hole down them one had a plain nut and bolt through the other had a nut and bolt with a centre drilled hole tapped to take a pressure gauge .The plugs are pushed in the flue then tighten the bolts up they act a bit like anchor bolts and held up to about 40psi enough to prove he flue was sound. The plugs are the ones they use for the air lock when brewing wine hope this makes sense
Frazer


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## zeeprogrammer (Jun 19, 2010)

Awesome Pete. I'm very much looking forward to more pics.


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## doubletop (Jun 19, 2010)

fcheslop  said:
			
		

> Pete, On my last centre flue boiler I tested the flue by blanking the end with demijohn rubber plugs .Drilled a hole down them one had a plain nut and bolt through the other had a nut and bolt with a centre drilled hole tapped to take a pressure gauge .The plugs are pushed in the flue then tighten the bolts up they act a bit like anchor bolts and held up to about 40psi enough to prove he flue was sound. The plugs are the ones they use for the air lock when brewing wine hope this makes sense
> Frazer



Frazer 

Your approach occurred to me overnight and it's appealing. Making equipment that can be re-used and not affect the integrity of what you are building has to be a good idea. Trouble is my homebrew days are long past and anyway this is NZ and we make some good stuff here. I'll have to see if I can track down some stoppers from somewhere.

Zee

Just about to get into it; another cup of tea and I'll be out to the shop (I am a Pom so tea is a mandatory part of the process)

Pete


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## doubletop (Jun 20, 2010)

I eventuality made it out to the shop got myself organized. Its the down season here in NZ so my hearth makes use of the barbecue. As John said, "make sure you have enough heat available". This big kahuna burner does 6.7kg of gas per hour and was the cause of the melted bushes on the last boiler..







I re-did one or two of the joints on the burner tube cross pipes as you can't have enough solder on those joints and nobody is going to see them ever again.

I then prepped the first plate in the boiler body. As before; the rivets aren't riveted they are just pushed into the holes. They serve to hold the plate in place and add a bit of bling to the finished boiler. The silver solder will hold them in.






Even with the big burner and gas flames squirting out of every orifice it didn't seem to have enough heat. I got half of the plate soldered pretty well but by that time the flux seemed to go off. So I let it cool and gave it a few hours in the pickle to get it nice and clean and start again. However this is what the tube looked like after each go






All black an sooty. I came to the conclusion my gas was coming to the end and I wasn't getting enough pressure so the flame wasn't burning efficiently (This burner needs 4bar). So that was it for the day. I've refiled both my bottles ready for another go. In the meantime both parts have been in the pickle ready for round 3.






Looking from the inside the tell tale solder ring is just about there but not enough in one or two areas as far as I am concerned .






That's it for now

Pete


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## doubletop (Jun 24, 2010)

With the gas bottle refilled and up to pressure I did a bit more to finish the intermediate plate and was happier with the joint. Time to do the burner and flue tubes, this went so well that I was done after 10 mins and after it had cooled down it went into the pickle. I'm now getting joints closer to what I am expecting. As Marv said on Zee's, thread beginners tend to use too much solder. I'm still doing that but getting a bit better.






Time to do the flue/burner end. Prior to applying the flux






Again it only took 10 mins as I only did the burner and flue tubes at this point. I had the boiler horizontal to minimise the chance of the cross tubes falling out with the torch throwing heat straight down the burner tube. I'll do the flange with the boiler vertical, like this, and the heat applied to the outside. That way it should keep the heat away from the burner tube to some degree.

Straight after completion and still in warm state. I'm still not sure about the blackening and still think its to do the burner not working efficiently despite the full bottle of gas. _(I got it from BP but I don't think its appropriate to make any smart comments at the expense of you poor guys on the Gulf Coast. I spent some time working at Fort Walton Beach once and can't imagine the mess it must look right now)_






The weekend should see the flanges done and if that goes well I can get the bushes in. It really depends on the number of solder/pickle cycles that are needed as the whole thing is now taking a day to get really clean in the citric acid pickle. Maybe time for another $5 outlay for a refresh.

Pete


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## bearcar1 (Jun 24, 2010)

Your boiler is shaping up a treat there Pete, as for the sootiness on the shell in that last photo, I was always told that condition was the result of too much gas and/or not enough oxygen in the flame. A carburizing flame I believe they call that condition. Either that or crud in the lamp tip orifices. If you just got a new bottle of gas, perhaps the pressure is a tad on the high side causing the flame to burn 'rich'. At least that is my unsolicited thoughts on the matter. Keep up the good work, TallyHO!

BC1
Jim


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## doubletop (Jul 4, 2010)

Jim

I'd thought that was the problem but I'm not sure what is causing it sometimes it comes out covered in black and other times its pretty clean. I've got the Sivert regulator on the bottle, max pressure for the big burner and minimum for the smaller ones. 

Anyway I've the reason for no posts for a while is I've been chasing leaks. 

Water tube extended bushes






I got the end plates on and the bushes fitted and started the pressure testing, Three of the rivets leaked, in fact the first one shot across the workshop as it wasn't soldered in at all, one bush leaked, then another, then one of the flue return tubes. Each time clean the job, flux the joint, fix, back into the pickle ready for the next test and another leak to be found. It got a bit disheartening and all the time I'm hoping I am not destroying the joints in the burner cross tubes. They can't be fixed.

I realise now that I should have put the boiler end plates in the other way around as they can't be seen when the boiler is finished, then the positioning rivets wouldn't be under pressure, in fact I could have riveted them. I'll change the plates on the next version of the drawings.

Anyway today tested at 150psi and it held it for half an hour that's 3 times the pressure I plan to use this boiler so now time to move on.






Again I'm using the mountain bike shock pump for pressure testing. And yes the boiler and pump are full of water *not air.* 

That's it for now. I've installed the super-heater, made some of the pipe fittings and soldered one of the outer end plates. It's in the pickle right now so I show you that later.

Pete


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## tel (Jul 4, 2010)

Ahhh, the joys of boilermaking!  The end results are usually worth it tho', and yours is certainly going to be.


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## Blogwitch (Jul 4, 2010)

Pete,

If things never went wrong, wouldn't life be boring?

If it can be fixed, there was never a problem in the first place, it is just another part of the build.

Now the crucial bit is done, it should be downhill all the way now.

Great build.

John


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## doubletop (Jul 4, 2010)

Thanks guys; it certainly felt down somewhere in the past week or so. 

It had got to the point that yesterday, I thought I'd console myself by doing something else and have another go at safety valves now that I have the Kozo Hiraoka article on the same. Also followed Johns mantra of always make more than one. Made D bits to drawings, went through the step by step instructions in the article, seated the ball did the vacuum test. Nothing.. reground the D bit, re-cut the seat, re-seated the ball, did the vacuum test. Nothing.... So still no working safety valves. It's a damned good article though.

Anyway; I'm certainly over the hump as far as this boiler is concerned and today was a great day in comparison to others recently.

regards

Pete


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## Diversion900 (Jul 4, 2010)

Lookin' good so far Pete, don't let it get ya down mate.

this hobby of ours can really test our patience at times, I have had plenty of days like this. :  My experience showed that it all works out in the end.

I'm just hoping that you find all the bugs before I do. ;D

Mine is temporarily on the back burner while I finnish my latest engine (verticle twin rotory valve).


Cheers, Neil


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## fcheslop (Jul 4, 2010)

Hi Pete, looking good I'm really getting boiler envy :big:
regards Frazer


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## Maryak (Jul 4, 2010)

Pete,

That's looking really nice. :bow: I've yet to see a new boiler of any size come up to pressure 1st time and hold it without some minor leaks somewhere. All part of lifes rich tapestry.

Best Regards
Bob


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## doubletop (Jul 5, 2010)

I went out tonight to do the second outer end plate after successfully fitting the the first outer plate yesterday, start to finish 10 mins max. I went thorough exactly the same procedure out of the pickle, rinse, dry, flux the joints, assemble, flux the rivets and insert. Heat, allow flux to glaze and flow, apply solder and all I got was solder globs, reheat re-flux no go. So its cool down and into the pickle until tomorrows installment.

What is going on???

So I write this with Desperate Housewives running in the background. Forget Desperate bloody housewives..........

Pete


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## tel (Jul 5, 2010)

Sounds to me like not quite enough heat - when you get a blob keep pouring the heat in and it should flash and follow the torch around smooth as silk.


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## Blogwitch (Jul 5, 2010)

As Tel says Pete, more heat required.

Don't worry about previously made joints, if you don't go absolutely stupid with the heat, they will be perfectly OK.


John


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## doubletop (Jul 6, 2010)

And of course gents, you are right again. 

I hadn't read your posts when I got in tonight, but eager to get this sorted I went out before dinner. Got it out of the pickle, rinsed, dried, fluxed and had the burner on full loud and still had the same problem. "Sod this" I upped the gas regulator half a notch and just about straight away the blobs disappeared down the joints like scared rabbits. I was back in the house drinking tea within 15 mins of starting the job, and smiling.

There is a trend here, around gas pressure, and it may be as simple as ambient temperature in this case. Over the weekend we were at about 13degC. Last night a cold front came in and we were down to 10degC or maybe even 9degC. The last time I was having trouble I was running out of gas and as soon as the bottle was filled the problem went away.

I still have the ogre of the melted bushes from the last boiler but then they were brass bushes on a small end plate, I had hopeless flux and was using my humongous burner out of frustration. Other than that as you say Bogs the possibility of melting the other joints is slim with all this copper in the boiler the heat has to be directly on the joint to get the solder to flow.

Anyway its in the pickle now, club night tomorrow so pics probably Thursday

Happier chappy

Pete


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## tel (Jul 6, 2010)

Glad you got it sorted Pete.


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## doubletop (Jul 8, 2010)

As promised heres some pics after the outer end plates were (finally) fitted

Door end with the coil of 1/4" tube for the super-heater in place but the ends not finished






Flue/burner end with water gauge bushes






I bolted on a few bits so I could take it to the club and show it off last night

Flue/burner end with the burner in place






Door end with door in place. As I've said before this door isn't functional and may even be a problem as it needs to be sealed properly so the return flues work properly. I'm looking for a way to seal it, fibreglass or asbestos (or similar) cord






Hopefully that's the hard bit over and I can now work on the details. I've decided I'm going to conform and paint this one black or maybe maroon as Bogs suggested.

Pete


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## tel (Jul 8, 2010)

> As I've said before this door isn't functional and may even be a problem as it needs to be sealed properly so the return flues work properly. I'm looking for a way to seal it, fibreglass or asbestos (or similar) cord



Or a smear of Boss White, or even fireproof cement, around the door before you latch 'er up.


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## doubletop (Jul 8, 2010)

tel  said:
			
		

> Or a smear of Boss White, or even fireproof cement, around the door before you latch 'er up.



That may just do it thanks

Pete


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## Diversion900 (Jul 8, 2010)

Nice work Pete.

A couple of questions......

it seems like a large diameter circle for the super heater, I thought it would've been better to double it back up top instead of going round the outside ?

and how come the exit points to the ground ?

Cheers, Neil


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## doubletop (Jul 8, 2010)

Well spotted; its a rough copy of the sketches in the KN Harris book and after Id done it I had second thoughts. I may pull it out over the weekend and make a copper block V type that comes straight down from the steam dome and then does a hard right out of the exit hole with the V over the end of the burner tube 

The reason the exit curves downwards right now is the shape it took up when I was threading it in it. Its annealed and will straighten up OK. Its going to get shorted considerably.


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## doubletop (Jul 11, 2010)

Latest drawings can be found here. A few more bits of detail and the main boiler plates reversed to help in construction.

http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item285

There are undoubtedly errors in these drawings but they give you the general idea of how it goes together.

Pete


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## doubletop (Jul 14, 2010)

Done the final bits and bobs 


Made the door handle and latch
Made the funnel cap
Painted the detail on the mounting feet
Changed the super heater to be a copper block rather than the coil. Fortunately the door was big enough to get the assembly installed without having to solder it up in situ.
Gave a a bit of clean up with a small rotary wire brush in the pillar drill.
Installed the fittings

















Sorry the photos are a bit blurred the flash wasn't giving me the results I wanted.






I may strip it down again and do one last pressure test and then it may be time for its first steaming over the weekend.

Pete


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## tel (Jul 14, 2010)

It's really looking the part now Pete - ONYA!


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## Diversion900 (Jul 14, 2010)

Great job Pete.

Let us know how the extentions for the level guage go, if they cause any drama's or not.

On another note, a visit to my local scrapyard yesterday had me returning home with a 12" length of 6" diameter copper pipe with 2mm wall thickness. ;D would you believe $20 and it was mine.

I may have to re think the dimentions of my new boiler !

Cheers, Neil


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## zeeprogrammer (Jul 14, 2010)

That looks great Pete. I hope a video is being considered. ;D


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## doubletop (Jul 18, 2010)

Thanks again everybody.

The promised firing happened to some degree of success yesterday with wisps of steam coming from the flue. Which is always a gratifying moment.

And you can tell there's a "However" coming next.....


The burner wasn't stable it would go out or flare and was making a pulsating noise. I spend some time trying different combination of jets, air hole sizes but did have some success with a simple blow torch I have, which my burner is based on so I am in the process of making a newer more exact copy of the original torch.

The wisps of steam didn't stop which indicates there's a leak somewhere and not just a bit of dampness drying out.

The pressure gauge didn't indicate which needs investigating. There was plenty of steam when I opened up the steam valve (no engine connected yet.)

The camping gas cartridge I am using ran out of gas so I need a new cylinder 

Things are a bit slow today as I went to a 60th birthday party last night - Mine. So no shop time today

Pictures and videos are de rigueur so will be provided in due course

Pete


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## Blogwitch (Jul 18, 2010)

Happy belated birthday Pete.

Don't worry too much about having a leak, there is a rescue if you can't get the boiler up to silver soldering temp in a local area.

Have a search for a product called Comsol. This is a silver bearing soft solder with a temp range of around 300° C, and is normally used for sealing small areas of leaking silver solder jointing, where you can't get the area up to the high temps required for a silver solder repair.

In the early days, boilers were completely assembled with this stuff, but now, I think it is used just for doing small repairs.


John


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## tel (Jul 18, 2010)

Well, 'appy birthday for yesterday Pete - I turned 63 yes'dy as well.


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## doubletop (Jul 18, 2010)

John

I think it is the superheater. But it can be no more than a dribble as I got steam pressure OK. I had also done a pressuer test to50psi with all the fittings in place and it held that OK. I'll see if I can source so Comsol, I'm now sourcing my solder products direct from the NZ wholesaler that supplies BoC so I'll start with them.

 'appy birthday to you as well Tel. The 'real' day was last Monday but Saturday was the best day to celebrate. The All Blacks were also playing South Africa in town so the whole place was in a bit of a party mood. Which led to a late night after we all left the restaurant.

Pete


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## Diversion900 (Jul 18, 2010)

Happy Birthday Pete.

Sorry to hear about the problems, might be worth bypassing the superheater and testing that way.

Cheers, Neil.


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## doubletop (Jul 18, 2010)

Neil

Thats the plan. I've got a spare port on the steam dome where I can put the steam valve and I can blank off the super heater port.

First job is to get this new burner working

Pete


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## Maryak (Jul 18, 2010)

Happy birthday Pete and Tel :bow: :bow:

Good luck with the leak and the bummer pressure gauge.

Best Regards
Bob


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## Diversion900 (Jul 19, 2010)

I've been looking into those mini hiking burners with the ceramic type burner......

Not sure yet, so still thinking.

Now that I have this piece of 6" pipe, I think the burner could be a lot bigger than the ones I have been looking at by the time I re-design the boiler layout.

Cheers, Neil


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## doubletop (Jul 19, 2010)

Tested the presssure gauge and it may have just been a bid of crud in the syphon U bend. Anyway it works now

I've just spent the evening trying out the burner again. What worked Saturday decided it wasn't going to work today. Fiddled about with diffrent combinations of jets, gas valves, and burner heads, jet postions, air hole sizes and I eventally got it going and managed to raise 10 psi in about 3 mins. 

It has a degree of ferocity and instability that would indicate that if you put this setup in a boat it would most probably emulate a Viking funeral pyre by the time it got to the middle of the lake!! As it stands what I have at the moment is on the brink of being OK for this through flue boiler, but for now I can't turn it down without it going out. As a pair with a figure 8 water tube flash boiler it would be brilliant.

Anyway I'll persevere and get something sensible working in due course. At least I'd hope to. I've now got so many combinations of gas valves/regulators, jets, adaptors, burner heads, sheets of ceramic and they are all cross compatible that something should work. 

On that; I've realised that the pressure for a ceramic type burner is lower than that for a torch type burner, also most of the ceramic burners I've seen have a jet between 5 and 10. Does anybody have any basic rules for these things e.g gas pressure, jet size, head type etc. ????

Pete


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## Diversion900 (Jul 19, 2010)

Sorry Pete, can't help on this one.

The only ceramic heater I have is in my trusty butane soldering iron.... ;D

These ceramic burners are all new to me, by what Ive been reading they sure put out some heat though.
I am yet to find out if they will work when placed inside a tube, or if they need to be spaced back from the entrance a bit in order to get air?

I have only ever used metho on the little pot boilers I have made, this is my first multi-tube.

Cheers, Neil


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## doubletop (Jul 22, 2010)

Im back after three nights of going around in circles with various combination's of burner parts trying to get something to work. At the end of last night the gods were not looking down on me and I couldnt get anything to work. Even burners that had worked fine in the past just wouldnt light up. I parked everything and gave the evening up as a bad job.

Tonight I came home and started again. 

First burner Id made perfect; Poker burner, perfect, Old gas torch working again. Out came the calipers and drill rod to measured bores, fits, whatever they were all very similar. So the only variables I had were size 5, 10, 12 and 15 jets and two gas cylinder valves that had different flow rates. I systematically went through all the jets with my first gas valve and found the combination that worked on the original burner and then the poker. Back to the old gas torch got that going again. Tried my two copies of the torch and they both worked. Tried all three on the boiler and one of the new ones cut out once it was inserted the other worked to some degree. I adjusted the air vent adjuster and got it going fine. I was back at the burner Id made in the first post of this thread. Explain that!! Actually its about being methodical, logging results, analyzing trends and being thorough. Too many variables adjusted in the wrong order and youll never get there..

Anyway, as I had it going it was time to connect the engine steam it up and see what happened. Then you guys get the obligatory video.

[ame=http://www.youtube.com/watch?v=xLdz6jHvYi8]http://www.youtube.com/watch?v=xLdz6jHvYi8[/ame]

It took just under 3 mins to get to 20psi when about 3/4 full (up to the top of the guage) and water straight out of the tap. There was a bit of heat in the copper from a previous attempt but that was it. 

_(I'll come clean here; As its only running at 20psi I coupled the engine to the boiler with a bit of plastic tubing. The jump in the video is where the pipe blew off and I had to re-connect it)_

The boiler is looking a bit sad right now after three nights of throwing heat at it. But now I know it works, and pretty well if I say it myself.

I'll go and strip down tonight and get it cleaned up ready for mounting on a piece of wood with the engine. I'll do some photos when I get that finished.

Pete


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## Blogwitch (Jul 22, 2010)

Pete,

That is absolutely great, both engine and boiler in perfect harmony.

I don't know if you have steam lube in there or not, but I would recommend you get something in there before running too much.

Also, by the amount of steam you have around the engine, it looks like you could turn the feed pressure from the boiler down some, these engines really will run very nicely on about 10 to 15 psi of steam, any more and it is just a waste of gas and water.

Very well done indeed, a case of perseverance paying off in the end.


John


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## doubletop (Jul 22, 2010)

Thanks for your support once again John. 

Yes I had oil in the "Bogs Oiler" and only a few drops were left at the end of the run. Running on steam it ran really quietly, as you'd expect. That's why I shut the burner down at the end just to hear how quiet it was.

There are a couple of engine leaks but I've now got some Viton 'O' rings so going to take the pistons out an put in an O ring groove. And do the glands with O Rings (another Kozo article convinced me it was the way to go.)

I'm pleased I can make more steam than the engine can use. With the vertical boiler it just couldn't make enough steam even with the little single cylinder engine. But I do also have a new ceramic burner for that which I ran up at one point but haven't installed yet. On the last count I'm on my eighth burner, and some of those have gone through a but of an metmorphis over time. That was so frustrating the other night I've made so many gas burners that mostly worked pretty well first time and then nothing worked. I thought I was loosing it .

Pete


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## zeeprogrammer (Jul 22, 2010)

That was great Pete.
Beautiful looking boiler.
Thanks very much for the video.


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## Diversion900 (Jul 23, 2010)

Looks like the project is almost complete Pete, very well done indeed.

I like the idea of having more steam than you need, that means multiple engines can be run at the same time...... any thoughts on maybe a steam powered feedwater pump?

Any sign of interference in the level guage from the tube extentions heating up ?


Cheers, Neil


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## ozzie46 (Jul 23, 2010)

Well done Pete.

 Some day a boiler is on my to do list

  Ron


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## doubletop (Jul 23, 2010)

Carl/Ron/Neil

Thanks for your support. Tidy up time this weekend, its stripped down and in the pickle getting cleaned right now. Just about to pop out and get a bit of wood for a base. I'm working on the fixing to the support feet. It wasn't well thought through and not finished but had an inspiration during the week and I am halfway through a solution and just woken up with further ideas. We'll see how that goes.

Neil

I've made provision for a clack and had thought about a water pump off the engine. However, this is a wobbler and I think if they get too heavily loaded they would be more prone to blowing the cylinders and faces apart. I could do a separate pump but my inclination is to do what I set out to do, a 'proper' twin cylinder with valve chests. Maybe Bogs Paddleduck. I'm sure that could support a water pump.

Thanks for reminding me of the water gauge issue. There is a problem with the gauge during the multiple combination's of burners at one point it was burning out of the air holes and boiling the water in the glass tube. I fixed that with a plate between the burner and the gauge. It was removed when the burner worked properly but I may put it back. I am not convinced I am getting a true reading from the gauge, but it is working. But I don't believe the bushes are heating up excessively. The burner is throwing the heat into the center of the boiler past the bushes. Buy the time it gets back again, down the return flues the temp is way down.

Thanks again guys

Pete


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## fcheslop (Jul 23, 2010)

Hi Pete,Nice steam plant I know what its like with the burners for some reason mine never seem to work on completing the boiler but worked fine before .I find that fitting a small coil of old heater wire in the flue seems to help in preventing flame out .The twin oscillator should drive a feed pump as this is the type of engine I use in my boats .Hope you don't mind I have attached a pic of one of my open launch plants you can see the pumps and the boiler feet ,if the pics a problem I will remove it





best wishes Frazer


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## Maryak (Jul 23, 2010)

Pete,

Very Very nice. :bow: :bow:

Best Regards
Bob


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## doubletop (Jul 23, 2010)

fcheslop  said:
			
		

> Hi Pete,Nice steam plant I know what its like with the burners for some reason mine never seem to work on completing the boiler but worked fine before .I find that fitting a small coil of old heater wire in the flue seems to help in preventing flame out .The twin oscillator should drive a feed pump as this is the type of engine I use in my boats .Hope you don't mind I have attached a pic of one of my open launch plants you can see the pumps and the boiler feet ,if the pics a problem I will remove it
> 
> best wishes Frazer



Frazer

Absolutely no problem with you posting pics on the thread 

That looks very nice thanks. The tip for the hot wire re-igniter is a neat idea, I had wondered how people managed to save the situation after a 'flame out' with nobody in the cockpit to do the restart checklist. Floating bomb comes to mind.

Pete


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## doubletop (Jul 25, 2010)

This weekend was tidy up time and I decided to giv it a bit of a paint

Before





The paint






All together with the engine. 


























No it's not going in a boat I'm afraid, unless I need a break from the metalworking at some point and decide to do one.

Hope you've all enjoyed the journey

Pete


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## Blogwitch (Jul 25, 2010)

Absolutely great job Pete.

You have produced a very creditable and safe boiler.


John


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## doubletop (Jul 25, 2010)

Thanks John 

I've enjoyed this one, and of course the fact it started out as a sketch on a pad has made it even more satisfying.

Your assistance, as always, has been appreciated and having you, and the rest of the team, as my mentor has made the journey way easier than struggling along by myself.

I do need to get the drawings updated, which will require a bit of reverse engineering so I may do that in the coming evenings. Then I need to work out what to build next. It could well be Paddleduck, I just need to find a cylinder block.

Pete


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## Blogwitch (Jul 25, 2010)

Pete,

If you do decide on the paddleducks engine, to run on steam, the cylinder really should be cast iron, or at a push, brass, and if possible, shape it how I have done on the blinged one, that way there is less mass to warm up and keep warm. 
For running on air, those points don't really come into it, it can be made of almost anything and whatever shape.


John


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## doubletop (Jul 25, 2010)

Bogstandard  said:
			
		

> Pete,
> 
> If you do decide on the paddleducks engine, to run on steam, the cylinder really should be cast iron, or at a push, brass, and if possible, shape it how I have done on the blinged one, that way there is less mass to warm up and keep warm.
> For running on air, those points don't really come into it, it can be made of almost anything and whatever shape.
> ...



It is cast iron I was going to use as I haven't worked with that yet, so I do want to see how it machines. Also wanted to try making the Bogs fly cutter. I had planned to go to the scrap yard this weekend but had to do something else. Top of the agenda for next week though.

Pete


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## arnoldb (Jul 25, 2010)

Pete, very well done indeed ! :bow:

Good quality cast iron is very nice to machine, though a bit messy.

Regards, Arnold


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## ozzie46 (Jul 25, 2010)

Excellent work on the boiler.

  Have plenty of soap ready, the graphite from the cast iron really works into your hands. Mix a little oil in it and it gets everywhere.

 Ron


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## zeeprogrammer (Jul 25, 2010)

Beautiful boiler and engine. Very nice.
Shame about the boat. ;D

What is that one piece used for? The tube sitting under the fuel inlet?


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## doubletop (Jul 25, 2010)

Thanks Arnold, Ron and Carl



			
				zeeprogrammer  said:
			
		

> What is that one piece used for? The tube sitting under the fuel inlet?



The tube is the gas jet, a short length of copper pipe and the gas hose connector. It sort of looks messy when its in place 

Pete


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## joe d (Jul 25, 2010)

Pete

I'll add my "well done" to you as well. That turned out really good looking, as well as useful.
You've reinforced my desire to get going on a boiler one of these days.

Cheers, Joe


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## mcr (Jul 26, 2010)

Really enjoyed this thread always the first one I would look at a big :bow: thumbs up from me.
By the way it really should go into a boat.
Mark


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## doubletop (Jul 26, 2010)

Thanks Joe and Mark, and sorry no boat just yet.

Here's the final contribution, as promised, the updated set of plans. There may be a few dimensions missing and no doubt some errors but I'm sure you guys get the general idea. I've only got Visio 5 so no flash CAD stuff I'm afraid.

Pete

_(I'll post them in the download pages as well)_ 

View attachment Visio-Scotch Marine v6.pdf


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## Blogwitch (Jul 26, 2010)

Pete,

I didn't want to disturb your build while you were enjoying yourself.

There is a generally accepted method of getting the sight glass in a much better position.

I hope the C-o-C explains it OK.


John


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## steamer (Jul 26, 2010)

Well done Pete!

Glad you stuck to it through all the trials....they all teach you something.

Downloaded the plans and put them in my "archive"

Dave


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## Maryak (Jul 27, 2010)

Pete,

Fantastic :bow: :bow:

It's really great to see some boilers being made and having steam engines running on steam. IMHO our forum is rounded out with threads like yours - Thank You. :bow:

Best Regards
Bob


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## doubletop (Jul 28, 2010)

John

You are right (again  ) I should have looked at alternatives and it wouldn't have been a problem to retrofit near the end. But its painted now so the torch is staying well away from it.

Dave 

You are welcome to the plans hopefully they will be of use one day. If only if its only for one of the parts or ideas or even as a reference for 'I wouldn't have done that'

Bob

Thanks; I can't see the point of steam engines without steam. It probably goes back to when I was 10 and my stationary Mamod. With the help of Mecanno my engine didn't stay stationary for very long.

No doubt more boilers will come with later engines.

Pete


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