A small boiler

[Bogstandard]

Rich,

Great job on the hearth, that one should last a lifetime.

John

 

[CrewCab]

What a silly fellow I said. Never mind. Well something along those lines.

Glad it's not just me that has "those" moments then ;D

CC

 

[BobWarfield]

Great thread!

I can definitely see a boiler project in my future.

Best,

BW

 

[firebird]

Hi

Nothing done on the boiler today. I decided to make a tool that I have been meaning to make for some time. Very often I will drill a hole (or holes) tapping size in the mill and then have to remove the part to tap the thread. It would be much easier to tap the hole while still set up in the mill, with the chuck still in line with the drilled hole. If some sort of holder/tap wrench could be made I think it would get a lot of use. Briefly this is what I came up with.

I'll post a blow by blow description in the tools section

cheers

rich

 

[firebird]

Hi

Fathers day today so I get to play in the shop. I decided to drill some holes in the boiler barrel. This needs some careful setting up. Firstly I turned a bit of oak to a good fit in the barrel.

The barrel was then mounted in the mill using a rotary table and tail stock using a laser to centre it.

A marker pen in the chuck to give me a line that I can see.

Using the DRO to get the right place 2 holes were bored/drilled for the dome and pressure relief valve. Its the first time I have used a step drill but I got on ok with it. I took a short bit of video, I hope it works.



Cheers

Rich

 

[Divided He ad]

Perfect... Indeed Rich. I like the set up for mounting the tube ;D

Are those lasers good?

Are you now a convert to the step drill? I use them allmost every day in work and find them extremely useful.

One of my favourite drills for thin sheet (well they will go through up to 4mm!)



Ralph.

 

[chuck foster]

i just watched the video and on the second hole you drilled the camera makes the chuck look like it is going one direction and the drill is going the other direction :

by the way i 'm following this post with great intrest and enjoy all the comments and suggestions.one day i hope to find time to build a small boiler, and these posts will be my reference to build it the right way.

keep up the good work and thanks for all the info........

chuck

 

[firebird]

Hi

The step drills are really good. Very clean holes. The set I have is metric and increases in size by 2mm increments, 6 8 10 etc even numbers. If they are available in imperial and odd number metric I'll get them. The laser is brilliant, especially in conjuction with DRO. The main advantage is you don't have to half anything. Wherever the dot is thats the centre line of the quill. It won't replace a dial guage for really fine work but I have used it for most work I do. Its on a 6mm shank so fits in a 6mm collet. If you put it in your chuck you can see quite easily how much runout there is. In use just move the X Y till the laser dot is on the corner (or whatever datum point your using) then zero your dials or DRO. Thats it.

Well tonight I drilled all the holes for the heat transfer studs. Using the same set up in the mill. I'll bore you with a bit of maths, not my favourite subject but I muddle through in my own way.

The boiler diameter is 2.980 inches.
The formulae for finding the circumference is pie X diameter (How do you type the pie symbol on a keyboard?)

Pie = 3.142

3.142 X 2.980 = 9.363

The circumference is 9.363

Divide 9.363 by 360 (360 degrees in a circle) = .026

1 degree = .026

19 degrees = .494

.494 is near enough to 1/2" for me

The first step is easy, just turn the rotary table through 180 degrees.

The first row of holes to be drilled is 1/4" off this centre line so turn the rotary table 9 degrees and 30 minutes. set the drill at the first hole and drill. Then wind the X table across 1/2" and drill the next hole, 9 in all spaced at 1/2"

Turn the rotary table through 19 degrees and drill the second row of holes. Note the offset spacing.

Drill rows 3 & 4.

I hope I've explained that well enough.

I just had time to make one of the heat transfer studs.

My parting off tool is 2mm wide. I have to make 36 of these studs so that will add up to a fair bit of waste. I think I'll set up a stop on the bandsaw and chop off 36 lengths. The length doesn't have to be deadly accurate and they don't need to be faced . Half will be inside the boiler and the external half won't be seen.

Cheers

Rich

 

[rangerssteamtoys]

Looks great, the heat transfer studs are for heating the boiler faster right? This idea is new to me, but almost everything is new to me.

 

[firebird]

Hi Ranger

Yes thats right. If you go over to the questions and answers section and look at 'WHAT IS IT' where this topic started you will find some drawings and more info.

Cheers

Rich

 

[firebird]

Hi

Nothing done in the shop over the last couple of days but I have been thinking about the silver soldering. The sequence I have in mind is to first solder in the 36 heat transfer studs followed by the 2 end plates. Next the 3 stays then the water guage bushes and the injector bush and finally the steam dome and pressure relief valve bush. Any thoughts on that? Would you solder all 36 heat studs in at once or one row at a time?

Going back to the burner Sandy suggested I should make the jet size 0.5 or 0.35. I now have some small drills in that range. Am I right in saying that these small drills need to be used at quite a high speed. Maximum speed on my mills is 2000rpm.

cheers

Rich

 

[SandyC]

Hi Rich,

Looking good so far...... I would assemble the end plates, stays and end bushes first (all as one assembly)... fit the stays with the mushroom heads at the same end as the bushes....apply plenty of flux as you assemble, making sure the end plates are aligned properly..... stand the boiler on some supports which will allow the plain ends of the stays to remain clear of the hearth...... solder the first end around its rim (keep the flame more on the barrel whilst doing this joint, to ensure correct penetration of the solder), and then work your way in towards the stays, soldering the bushes as you come to them..... finally solder the stays.....you can add more flux as you go, should it be necessary.

Allow to cool,enough to handle...turn over and support on the soldered end..... check the second end joints for flux, add more if necessary, and then solder this end...rim first, followed by the stays.

Drop the whole thing in the pickle for a couple of hours, when it has cooled enough to easily handle.

I would next do the studs...... assemble/insert them all at the same time, fluxing as you go and then gently heat up as a whole...this will solidify the flux (boils off the water) then you can concentrate on soldering each row at a time.... keep the flame more towards the barrel, since this will take most of the heat....the studs will heat up more by conduction.

TIP... if you can source some 0.8mm dia or 1mm dia easy-flo silver solder wire (Blackgates engineering stock it) you can make the job of soldering the studs a bit easier by making small rings of solder with the same ID as the OD of the studs.... slip one over each stud after you have insert it into the shell and fluxed it...push it gently down into the flux, up against the barrel..... these will melt and flow when the correct temperature has been reached...... saves a lot of time and gives less chance of unwanted excess solder running around the barrel.


Finally (after cooling down enough) turn the boiler over, and give the areas around the dome and safety valve bush a good scrub with some oil free steel wool, or med wet and dry, and fit the dome and safety valve bush with plenty of flux..... gently heat up again keeping the torch moving over the outer shell then concentrate the flame more around the bush, followed by the dome...... Allow to cool...drop the whole thing in the pickle and have a beer....you have a boiler.


Small drill are best run as fast as you can...and a peck drilling action (to clear the swarf (chips)) will be best.

Keep happy.

sandyC  ;D ;D ;D

 

[firebird]

Hi Sandy

Well I pretty much got the whole assembly back to front there didn't I. I'm glad I asked anyway. Always keen to learn from someone who's done it before. I can see I will need at least an uninterrupted afternoon to tackle the soldering so it may have to wait a while. I don't want to rush in and spoil it, not having come this far. I have one of those dremel type tools that runs at very high speed. I'm going to see if I can mount that in the mill for drilling the jet holes. Many thanks for the advise.

Cheers

Rich

 

[firebird]

Hi

I chopped all the heat transfer studs off in the bandsaw then turned them all to length,3/4".

Then turned half the length, 3/8" down to 5/32".

I have cut the 3 stays to length and cut a thread on the end of each. I'm not sure yet how I will mount the boiler in its frame work. I may well cut the threads off one or two of the stays after they have been silver soldered in but better to have the option now I think.

I have cleaned up all the parts with emery and given the barrel and end plates a quick buff up.

All the parts chucked in the pickling solution.

Does it matter if the parts are left in the pickle till I'm ready to solder?

I'm not happy with the dome with its 'OFFSET HOLES' so I've started to make another.

Cheers

Rich

 

[firebird]

Hi

I made the new dome today. I'm happy now.

cheers

Rich

 

[firebird]

Hi

I still haven't found enough time to attempt the silver soldering, I'm going to need at least 3 or 4 hours clear to set up and have a go so there has not been any progress with the boiler. I have managed to find half hour here and there so I turned my attention back to the burner, or more precisely how to drill the very small holes, 0.5mm or less, for the jets. I bought some drills ranging in size from 0.4mm up to 1.0mm and had a play with them in my small X1 mill. The o-10mm chuck is a bit cumbersome for these tiny drills and the maximum rpm of 2000 isn't fast enough. The following photo shows what I came up with. Its a Dremmel type tool that I got from B & Q some time ago for £20.00. Its 12 volt, runs off a power supply and has a variable speed of 0- 20000. Its held in a alluminium jig which has a 1/2" stub which fits into a 1/2" collet in the mill. It works a treat. I'll post more photos and a bit of video in the tools section of this forum that shows the component parts.

cheers

Rich

 

[firebird]

Hi

Well I finally got to do some silver soldering tonight. I set up the brazing hearth on a cheap workmate type bench. I Cut up a few small pieces of the fire brick to use as stands. I decided to braze in the 3 bushes in the end plate as a first go. All the boiler parts have been in the pickle bath for over a week now so are as clean as they are ever going to be. The end plate and 3 bushes were washed in clean water. I mixed up a little fluxed and coated the holes and surrounding area in the end plate and fitted the 3 bushes. The 2 bushes that will accomodate the water guage were fitted with the alignment jig. The propane torch quickly brought things up to temperature and the silver solder rod touched on. It melted and I could see it run around the bushes.

The bushes set up.

In the brazing hearth

After brazing.

Looking inside the solder has run all round the bush.

After an hour or so in the pickle.

I'll clean out the threads and try the water guage next. If alls well then I'll carry on.

I'm pleased with that and feel confident now to tackle the next stage of soldering.

Cheers

Rich

 

[Bogstandard]

You've got the hang of that Rich.

Nice one

John

 

[rangerssteamtoys]

Looks to be a great soldering job. I have some soldering to do on a boiler my self, but thats not for a few days.

 

[firebird]

Hi

I left it in the pickle over night and tonight I ran a tap through the bushes to clean out the threads. I fitted the water gauge top and bottom unions and then fitted the glass tube. It went straight through with no effort at all so the alignment jig worked. I haven't cut the glass to size yet.

Cheers

Rich