My version of SandyC's 3" vertical boiler

[firebird]

Hi DT

The ring of solder inside your boiler should have worked perfectly. I would have heated it from the outside until the solder flowed. You seem to be doing everything right so I can only assume that the solder/flux combination isn't compatible?? Nice looking safety valve though.

cheers

Rich

 

[doubletop]

I've supposedly got easyflow flux and solder and it hasn't worked. Applying the heat on the outsides had the inside glowing red. Anyway been on the phone to suppliers and waiting for a call back on solder and flux availability. Hopefully I can pick it up tomorrow and have better news at the end of the week.

In the meantime it will be blanking plugs and your pump, ready for pressure testing when I eventually get it together.

 

[ianjkirby]

I'm betting my cynical mind has already puzzled out the answer to this question, but...

Is there any consistency in the color coding from one manufacturer to another?

If so, is there a chart detailing the code?

Hi Marv,
It will depend upon whether your country has national standards in place or not. Here in Oz, Standards Australia, the quasi-governmental outfit responsible for such things, has standards for all sorts of things, including colour codes for silver solder, and mfgrs here pretty well go along, in order to remain viable in the market. If I can locate the colour code, I will post it, but it might be different in your country, so check first.
We even have a standard for miniature hobby boilers, but thats another story!
Regards, Ian.

 

[doubletop]

The silver solder saga continues and I have tracked down a source in NZ and now have some on order. It appears all roads lead back to Johnson Matthey in UK or AGR Matthey in Oz.

I had (or thought I had) some Easyflow and it had been labeled 620degC that would have been Easyflow 45 or Easyflow 55, which later became known as Silverflow 55 and then Silbraze 55. The “55” is 55% silver I assume, and the more silver the lower the soldering temperature . (see attached)

I found Kendalls, www.kendalldistributors.com, are the NZ importers and a very helpful person there had my small order sorted in 5 mins. I have ordered the Silbraze 56. However, be ready for the shock its $1120/kilo ex GST. Approx 100gms or 8 rods 750mm x 1.6mm was around $100.

I went for the Silbraze because of its relationship to Easyflow and had sourced Easyflow flux last week. Kendall's will do all the fluxes as well.

When it arrives I’ll let you know if they are colour coded in any way.

(here's a link to a preview of the relevant AU/NZ standard, which references AN, EW and ISO standards and covers identification and marking so there probably is a standard colour coding system but I'm not about to buy a copy of the full standard to find out. http://infostore.saiglobal.com/store2/PreviewDoc.aspx?saleItemID=440304)



View attachment SilBrazAlloy_range.pdf

 

[firebird]

Hi DT.

That's very expensive. If you get a spare minute have a look at this site

http://www.cupalloys.co.uk/c.do?category=26&page=1

Some very useful info there as well. (I have no association with this company other than a customer)

I copied and pasted just a short extract from their home page.

842

This is the alloy most widely used by the model engineer.
It contains 42% silver, cadmium and conforms to BS EN 1044 AG303
Melting Range 610 -620 °C
It is free flowing, offers excellent joint penetration and has the lowest melting range of all silver solders.
It is available as wire 0.5 & 0.7mm dia, rods 1.0, 1.5, 2.0, 2.5mm dia


842 Silver Solder Rod 1.5mm dia x 500 (5 rod pack)
842 is 42% silver, cadmium bearing alloy. Melting Range 610 - 620° C Conforms to BS EN 1044 AG 303 Price includes P&P. There is no VAT
Our price: £14.20

And the more you buy the cheaper it gets.

I don't know if they ship worldwide but that sounds a lot cheaper here in the uk.

Cheers

Rich

 

[doubletop]

Firebird; thanks for the info a very useful website.

My silver solder arrived yesterday and I had a successful evening. More on that in a later post. By the way it wasn’t colour coded in any way.

The Cupalloys prices do look attractive however I’ve just done some price comparisons of the 456 Silver Solder Fluxed Rod 1.5mm dia (5 rod pack) as I had purchased 56% from my supplier

Cupalloys 456 - 56% 5 x 500mm x 1.5mm = £20.50 GB

Kendals Silbraze56 - 56% 8 x 750mmx 1.5mm = $104 NZ

NZ Dollar exchange rate right now = £1=$2.104 NZ

£20.50= $43.13

$43.13/(5rods x0.5 mtr) = $17.25/mtr

$104/(8rods x 0.75mtr) = $17.33/mtr

Spookily similar, however my $104 did include shipping and GST (VAT equivalent) but I did manage to get some discount.

I don’t have a price for the 46% and on a quick look I can't find anything on the Kendall's website

More on the boiler later with pics. Hopefully I’ll have it all together by the end of the weekend. Only the last end plate to go. Looking for a local supply of O rings right now so I can make the pump ready for testing

 

[doubletop]

I’ve finally got the silver soldering sorted. The answer is obvious to all and no doubt features regularly on various posts. FLUX, FLUX and more FLUX.

I had read about it and was concerned about flux life and once it appeared to start deteriorating I had assumed it was done. In fact the “deterioration” was the state it needed to be in for effective soldering. The tips on the Cupalloy site, pointed to by Firebird, are useful http://www.cupalloys.co.uk/silver-soldering-tips-c25.html and when I re-read my copy of Martin Evans “Model Locomotive Boilers” it all became clear.

Anyway all the silver soldering is now complete, although not to the standard I would have liked but I am reluctant to try to fix it further at risk of messing the whole thing up. I’ve lost count of the times I’ve reworked this. Basically it’s been numerous cycles of solder. stop, cool, re-pickle, clean, dry, re-flux and try again.

This is the first end plate looking from the inside showing a clear ring of solder that has come through from the other side and with evidence the rivets are soldered in. These rivets only serve to hold the end plates in position during the soldering so are not riveted, in fact it would be impossible to rivet the second plate.

The finished boiler with blanking plugs for ready pressure testing.

During the regular cycles of soldering while the job was in the pickle I had the opportunity to make more fittings

Boring the smoke stack adaptor. The engineers clamp on the top slide allows me to measure the depth with my digital caliper between the clamp and the tool post, rather than miss count the turns on the feed handle. Poor mans DRO.

Finished smoke stack adaptor and top cap

Of course having got this far I had to see what it looked like with the fittings added

You can see the globs of solder that have run down from the fittings. I’ll clean those up and they’ll disappear under the wooden cladding I plan to cover it with.

Pressure testing.

I expect that this may be a bit controversial but it did the job..

I was going to make the water pump based on the version Firebird did. But have had difficulty getting hold of the small O rings. I also needed a pressure gauge and was going to use the one from this pump as I’ve got two of these things.

They go to 300psi and are used for pumping the suspension on mountain bikes. They are fitted with a non return valve, pressure gauge and pressure release button (black button opposite the gauge.

I removed the gauge ready to make an adaptor for it to fit it to the boiler and in trying to work out thread types and sizes realized that the Schrader connector is 5/16 x 32 ME and would fit straight onto the boiler with a simple adaptor.

I’ll say it before anybody gets concerned. “Never pressure test a boiler with air, its extremely unsafe”. Although trying to do that with this pump would take you a very long time.

I fitted the blanking plugs, filled the boiler with water ensuring no air was trapped, Unscrewed the pump barrel and filled that with water and pushed the plunger in to purge the air. Fitted the pump to the boiler pumped water through the pump and got rid of all the air bubbles and then fitted the boiler filler plug.

I put the pressure up to 50psi, if the pump plunger was getting to the end of its stroke I removed it and, topped up the water and replaced the plunger. In fact I didn't even bother screwing the plunger back into the barrel as there is no pressure against it. With the water in the system it doesn’t take more than two strokes to get above 100psi

I had a minor leak from one of the blanking plugs, sorted with more ptfe tape and then did cycles of 50, 70, 90 psi for 15 mins and back to 0. The rated pressure for this boiler, supplied by SandyC with his design, is 90psi. I had reworked Sandys calculations with the materials I had used as was still well within his design margins. So I decide to go for 150psi for ½ hour. It dropped 20 psi over the ½ hour but I have no intent of running this for that long, nor at 90psi so it's good enough for me.

I believe I met the requirements of pressure testing and as long as water is used and not air, and if nobody has any other major issues with it I believe these bike pumps are pretty effective. They are $15US on ebay but no doubt can be purchased from your local bike store.

 

[zeeprogrammer]

Beautiful looking boiler and a very good post.
I'm watching with much interest.

 

[doubletop]

Thanks for the encouragement Zee; more to come yet.

Tonight I've made a right angle fitting for the pressure gauge so the U bend goes down and up to the pressue gauge rather than out perpendicular to the bush and then, down and up. If you follow. I annealed the pressure gauge pipe and bent it so now its in the pickle prior to soldering to the unions. While that is going on I've turned the gas tube for the burner.

Pics will follow when I've made up the pressure gauge pipework. I've also got a few bit and bobs on order which will hopefully turn up before Easter so I may get it steamed up over Easter, if only with the gas torch.

 

[Blogwitch]

Looks like you have got that silver soldering cracked now DT. Very neat job.

Now you have got the correct materials and a little bit of practice, you will always wonder why you had such a hard time of it in the beginning.

Once you get the skill, you should never lose it.

I'm looking forwards to what is to come.


Bogs

 

[doubletop]

Thanks Bogs

It really is a case of how hot is hot enough. After the melted bush incident, the knowledge that the flux looses its life I was very (to) cautious. it's a case of learning the tell tale signs of when the job is ready for the solder. Stabbing away with with the solder rod with flux on the end only results in solder where you don't want it when the end drops off. Ideally should be a case of heat the job, remove the heat, apply the solder and move on. But when is the right time takes practice. I not there yet but its coming.

 

[doubletop]

I’ve been up to two things since the last post. The burner and a “top hat” for the boiler to cover the end plate and bushes to finish it off.

Top Hat

I am looking ahead to the stage when the finish it when I clad the boiler in hardwood. I had thought of doing a single brass sheet to cover the bushes on the top and the soldering of the end plate, but I only had some 0.5mm sheet and that would have looked odd as a flat plate. I did think about making another former and annealing the brass and making it like another end plate. However, languishing in the pickle was a piece of copper tube ¼” long that just fitted over the outer diameter of the boiler barrel. I’d found it in the junk box in the early days and thrown it into the pickle thinking it may come in handy. It has.

What needs covering up….

I turned the copper ring to finish off the rough ends, rough cut a brass disk and soft soldered them together. I decided on soft solder as I didn’t want to see the sheet disintegrate and it’s at the top of the boiler so out of the heat and only decorative.

Finishing the brass diameter.

Holes for the flue, and three bushes

The finished “Top Hat” with fittings in place

This now gives me a point of reference to work to for the hardwood cladding.

Burner

I have been ignoring the burner until now. I needed some suitable copper tube to make the Sandy C burner and finally got hold of some from the local scrap dealer last week. Actually I only need 50mm but got a 2 meter length so a bit of scope for error!

Basic stuff now, cut the tube to length, into the lathe and finish off the ends. A disc of copper rough cut in with the jigsaw, Into the pickle and silver solder the two together. All went perfectly and a joint to the standard I’ve been trying to achieve. Very satisfying.

I’ve been looking at burner materials and the use of ceramic burner heads. Rather than go off and order some from Bruce Engineering in the UK I did a bit of digging around to see if people used plain old holes in metal, like my camping stove, barbeque etc. I found examples and decided to go that way first, so time for another aluminum former to shape the burner head.

While I was turning this down it occurred to me that it could be usefully used as an insert in the copper base so it didn’t collapse in the lathe chuck as it was nicely annealed from the soldering.

I then turned it down to size for the former for the insert annealed the brass sheet and beat it into shape. A series of 1mm holes later I had my burner head. In was conservative with the number of holes I drilled as I could always drill more but would have to start again if I’d done too many.

All the parts ready for assembly the burner tube and jet holder are to Sandy’s drawing

Remarkably these items are very similar to this in a burner I have for a Rob Roy 3 ½ inch loco, I believe this came from Bruce Engineering around 1993. Actually the jet holder fits the burner tube I have made. This proved very useful in testing as I used the Rob Roy burner as a point of reference and swapped the jet assemblies between both to check the results. The jet I was using came from an old Primus portable barbeque so I had no idea what size it was.

My burner alight

The Rob Roy burner alight, only noticeable by the ceramic glowing under heat

I then went back to the ceramics idea. One thing that NZ has is volcanoes and volcanic rock, pumice. Any tourists stopping by Lake Taupo will soon realize that the rocks on the beach are all pumice. Throw one in the lake and it will float until it gets waterlogged. The lake was formed 5000years ago by a huge volcanic explosion. Anyway everybody in NZ has one or two of these pumice rocks in the house somewhere, so I tracked one down.

I tested the pumice before I used it by blasting it with my biggest gas torched head for 30seconds. After another 30 seconds the pumice was cool enough it could be picked up by hand.

It is are cut easy with a hacksaw and can be sanded to shape

I drilled a number of 1.5mm holes (as that’s the size in the Rob Roy burner) and fitted the pumice to my burner base as a push fit. Firing it up was successful, this is alight but the flame can’t be seen, no glow on the pumice either.

This is early days for the pumice burner head and I’m afraid I’m not a source of supply for other experimenters. I live 300 km from the lake and I’m sure the local Iwi would have something to say about “their’ pumice. (if you are interested Google NZ, Iwi and politics)

 

[zeeprogrammer]

Fantastic post.
I enjoyed that.

 

[doubletop]

We have steam !!!

With the burner working it was time to get some water into the boiler and see if it would steam up. It was difficult to confirm if the burner was alight when installed so I have drilled some additional holes in the base so it can be checked. They will also help lighting it and I also recall Sandy C had advised Firebird to add extra holes in his vertical boiler base so the burner would work more efficiently. I only used the "watering can" burner head and not the pumice version.

Anyway here is evidence of the results.

It only got to 25psi. The home made safety valve doesn't hold pressure. I tested it with the mountain bike suspension pump I had used for the bolier pressure testing and found my valve leaks all the time. (you'll recall I had said that the schrader valve connection on the pump is 5/13 x 32 so a standard safety valve with those threads fits without adaption). I compared the results with a commercial safety valve which holds pressure up to about 90psi and then drops back to about 25 psi. So more work required on the home made safety valve, in the meantime I'll use the commercial valve.

I've started a base for the boiler and the wobbler engine, I had made as my first project, so both can be coupled together. I used the vertical slide in the lathe, lathe milling style, and routed the recess for the flywheel using a router bit in the lathe chuck.

More to come when I get it all connected up and running. before then I do intend to do more work on the burner, getting the gas regulation working better I think the current setup is running a little low on gas pressure, make a reversing valve and maybe getting the cladding underway.

 

[4156df]

Congrats on the steam!

I just got a look at your yesterday post. Well done. Using a bit of local pumice is just too cool.

Dennis

 

[shred]

Woo! Steam!

Getting the safety to fit well and not leak was a bit of a trial on my last boiler-- getting the ball seat just right was the key

Hm... I have a little chuck of the Lake Taupo shoreline somewhere here in Texas... Great fun was had as a child to throw rocks in the lake, then throw other rocks at the one bobbing around.

 

[Deanofid]

Great news on your successful steam-up, DT.
Really an interesting build here. I find it so neat that you could just grab a particular piece of rock, cut it with a hacksaw, and use it for your burner.

What is the lathe you're using?

Dean

 

[slick95]

DT,

Very Nicely Done :bow: :bow: :bow:

Just read the whole thread and really enjoyed all your efforts to document and share so we can all (me) learn from your challenges. I hope to build this boiler some day soon and I will certainly refer back to your build for direction.

Thanks again and Congrats

Jeff

 

[doubletop]

Thanks all for your posts over the weekend and to those others who have posted and I hadn't aknowledged directly.

Today got the gas regulation sorted. I suppose a lash up to the 9Kg gas bottle for my barbecue, a regulator from a camping stove, hose from an old gas torch and the regulator that came with the Rob Roy burner was bound to have issues. Notwithstanding that using the words "gas" and "lash up" in the same sentence isn't PC, the problem I had originally was too much gas. The rig I had been using wasn't giving me enough, requiring the taps fully open. Anyway a trip to the camping store and a closer inspection of the gas canisters they had (by carefully removing the protective cap in the store) finally revealed that I can get the correct cylinders in NZ, for what I had thought was an odd European fitting. Anyway all sorted for the cost of an $8 gas cylinder and now full control of gas/heat.

I've now sorted my cladding and cut 3mm x 10mm strips of hardwood by rigging up a mini table saw on the lathe. Another lash up I'm afraid, so no pics for the safety conscious. But I mounted a 100mm saw blade on a mandrill in the lathe chuck. Cut a slot in a piece of mild steel as a table, mounted it on an angle plate on the vertical slide, which was in turn mounted to the top slide. A piece of 15mm ally angle held with engineers clamps was the fence. The 3mm strips were cut from a piece 10mm x 40mm and then sanded ready to be cut into lengths for the cladding.

I am fully in regard of safety when I do stuff, but part of this game is about innovation, and at times not going to the store and spending $300 on tools that will only be used once. Believe me I spent an hour in the store today looking for a suitable tool I could use and then found the 100m blade and DIY kicked in.

Deanofid asked what lathe I am using. Its a 1930/40s Lorch. I think its an LL looking at this site http://www.s1p.de/05_w/05_ix.html. It's a bit of a bitsa with non standard headstock, metric top slide, imperial tailstock, washing machine motor, cheapo import vertical slide etc. but I've got three chucks, collet sets and various other bits a bobs so it does the job. No thread cutting and milling is as minimum as it can be, but the top slide is spot on so small items are a breeze. Basically Lorch are watch/clockmakers lathes and the basic design had been around since the 19th Century. Also see http://www.lathes.co.uk/lorch/

So next will be finishing the base, its had its first coat of poly now and a second will go on tonight, I'll fiddle about with the cladding during the week, or make the reversing valve I've been putting off, and then plumbing it all up.

 

[ss2fly]

Well done on the burner!!! NICE WORK.....

If the Pumice idea takes off, let me know, I have bags full of the stuff here.....all shapes and sizes... (stuff the IWI....)

Andy.