Building a Boiler for 3 1/2 Loco

[potty]

The parts were given a good clean and the rivets assembled as the rivet passed through the water space I threaded a ring of easy flow solder onto it, the parts were then fluxed and another ring of solder added to the outside of the boiler tube that way the solder between the plate fed the joint with the fire box and the outside solder fed the boiler tube: so that we did the outside and the inside at the same heating.

The boiler was placed on the hearth firebox down, and with a large torch in the firebox and one smaller torch on the end of the rivet, on a roving mission, the solder soon melted all looked good, so after 1/2 hr in the pickle this is what we got.

Inside



Outside



In between



All the joints had a nice fillet of solder

Before I do some more I need to get a few more rods of solder.

The next job will be the throat plate stays and the side stays:- 54 in total.

Cheers

Stew

[potty]

Picked up some more silver solder yesteday I recon I will have put about £30 worth into the boiler by the time its complete. Got on with drilling the rest of the stays after carfully marking out started by drilling the holes in the throat plate, its a a real awkward position up underneath the boiler tube, so that I can reach made up a extended centre drill with a 1/8" drill at the other end:- this is the beast.



Drill a hole in the end and stuck them in place with Loctite.

They ran out quite a bit so had to get them running as best I could with a perswader :hammer: also centre popping the hole helped because of the length it was quite flexable so it found position for itselfe.

This is the set up first all the holes were centre drilled.



And drilled 1/8 right through throat plate and fire box.



And her it is with the stays assembled.



Called it a day at that and went in to watch the footie.

Stew

[potty]

Got some more prep work done today for the next soldering campaign.

Drilled the holes for the side stays, 28 each side right through outer wrapper and fire box wrapper.
This is the set up the well annealed soft copper needed some support from Jacks, centre drill first then 1/8" drill, every fourth hole I pooped a rivet into to keep everything lined up



Gave the stays a trial fit, it looks like a hedgehog.



When it comes to soldering I'm going to thread a ring of solder over each stay as it passes through the water cavity, and one ring around the head of the rivet in the fire box that way each stay will get two rings of solder one to fill the fire box wrapper and the other to fill outer wrapper.

Made the rings by winding the solder around a length of 1/8 bar then snipping them off to make the ring.



And her they all are all 130 they used up 4 lengths of solder at 2 squid a length.



Cheers

Stew

[potty]

This soldering is getting to be routine with Johns help and guidance soldered the rest of the stays as for the crown stays we put a ring of solder in the water cavity and a ring on the head of the rivets positioned the boiler with the end of the rivets sticking down applied heat to the ends with the big torch and used the little torch for background heat and to locally boost heat where required, all went well, just a couple of stays needed a second heating and a bit more solder applying on the outside the inside (fire box) all soldered well.

Here a few pics







Taking it along to the inspector this Sunday whilst there I'll buy yet more solder.

Stew

[potty]

Soldered the fire box back plate in place, couldn't get hold of John at short notice so press ganged my wife onto the job, she was a bit wary of the roaring gas torch at first, but she soon got the idea and carried out instruction faultlessly with no arguments, which for a strong minded woman must have bin very difficult.

This is the result





Started to mark the back head out for the fire hole and ran into a problem, The drawing for the fire box back plate is wrong it doesn't match up with the position shown an the back head, it positions it too high, I'm stuck with what is a wrong part assembled to the boiler, at the moment the fire door will foul the water gauge,

It looks like I'll have to juggle thing around to get things to fit, still thinking the problem through.

Stew

[potty]

Nocked up a fire door this morning so I could 3D the problem :scratch:



Spent a bit of time down the club talking the option over with the guys, the best option would be to have the hinges at the bottom of the door, apparently on small gauge engines this arrangement is easy for driving, also did a bit of on line searching and found an engine the same as mine with the door hinged from the bottom it looks like the builder came across the same problem as me. Just to make sure I'm going to make the bottom end of the water gauge and the feed clacks so that I can check they won't foul the door, if they do only option will be to make a new back head and position the clacks under the door.

Stew

[potty]

Made enough of the fitting so i could try the fit out, for those interested this is how to fabricate small boiler fitting up, this is for the clacks.

First turn up the parts drill a cross hole in the body 3mm, on the union leave a small boss 3.05 mm dia and drill a pilot hole in the other end part way through, press the boss into the body and solder the bits together.

These are the bits



Bits prepped for soldering parts fluxed and a small nugget of solder put on the joint.



When you solder the bits together don't direct the flame on the job you'll just blow the nugget off sneak up on it with the heat when the flux will go white then black then it melts when it melts it will hold the nugget in place give it more direct heat untill you see the nugget melt and flow into the joint, pickle, then drill through the pilot hole into the body, thats it job done



Now this shows the problem with the fitting in the boiler the door fowls them.





I arnt half glad I made the the fitting as anothe problem materialised, you can't fully screw the bits into the back head they clash with each other.



I'm going to make a new back head but I'll leave that till next week as I'm starting to get pissed off with it and when that happens I make mistakes.

I may have said before that this was the last engine Curly designed before he passed away the drawing and ME article was finished off by Martin Evans and apparently the two didn't get on, the boiler fitttings are Martins designs they are obviously not what Curly intendes I wonder how many other builders have fallen at the hurdle.

Cheers

Stew

[potty]

Over the last couple of days I've made the Turret or Manifold to none steam people.

But first to finish off the clacks, the balls need setting down to do this take a new 3/16 stainless ball bearing put it on the seating, and with a brass drift give it a sharp biff with a light hammer, throw the ball away as you've distorted it, replace it with a new one. Now make the cap first measure the depth to the ball and calculate the length of thread required to allow the ball to lift 1/32 ".

Here we are one done No two measured for the cap.



Now for the turret this is made from phos bronze I've bin using calphos which is a leaded bronze that machine very nicely. The body of the turret is made from a length of 3/8" dia material:- drill 1/8 27mm deep and drill and tap 3/16 * 40 ME 5mm deep the body uses a 1/8 steal ball valve for the whistle so the bottom of the 1/8 hole needs to be square and accurately depthed, so I made a flat bottom drill and set it to depth to the chuck face against a steel washer, and just kissed the bottom to bring it to the correct depth.



3/32 hole drilled right through the bottom for the plunger.

Keeping the job on the bar transfer to the mill in spin indexer, and drill the cross holes 3.5mm to locate the fitting for soldering.



Back onto the lathe part off to length flip it round and drill and tap the back end 3/16 * 40 ME

The fitting as there were 4 to make 1/4 * 40 turn up a length of bar enough to make all four and thread it with a die.





The turn up a 2mm long boss for a tight fit on 3.5mm hole drilled in the body part off



repeat repeat repeat.

Then flip them round in a collet:- face centre drill and drill a 3mm hole part way through.



Turn up the other 5/16 fitting

Here they are assembled to the body.



And fluxed with a little nugget of silver solder waiting for some heat.



Again sneak up on it with the heat the flux will go white then black then it will melt more direct heat until the solder melts, pickle for 1/2 hr.

Then set up in the mill and with the aid of the 3mm pilot holes drill through into the body. If you stick a bit of wire down the hole you'll feel/see the drill start to tickle it when it breaks through.



Set the ball down on the seating as for the clacks.



Then make the whistle lever thing sorry this is the only pic I took.



And her we are turret finished.



With the bits made I can now see the best way to fit them on the back head, I think I'm going to black the bush up on the left next to the water gauge and move the boiler feed clack to the top right hand side.

Like this



Cheers

Stew

[potty]

Well I slowed things down a bit after the problem I had with the position of water gauge and clack bushes being 1/4" too high, I wanted to give the problem some thought before I jumped in. Just to recap I decided to hinge the door from the bottom, blank one of the bushes off and move one of the clacks to the side of the boiler, on Monday I opened up the hole for the fire door and drilled the holes for the 6 front stays, I was now in a position to solder the back head in the boiler but first I tried the fit of the longitudinal stays, they wouldn't fit they fouled on the fire box, the penny finally dropped the error wasn't with the drawing but with me.

:doh: :doh: :doh: :doh: :doh: :doh: :doh: :doh:

I'd only gone and positioned the fire box 1/4" too high.

Nothing for it but to make a new backhead with the holes for the longitudinal stays 1/4 higher.

Here's the old backhead with the new one cut out ready for bashing round the former.



I spent Tuesday making the new backhead, sorry no pics

Today another master class from John soldering the back head into the boiler:- her we have it







And the top boiler bushes for the turret and water gauge.



I'll take it along to the inspector this weekend for him to have one final look before I close everything up next week with the final soldering session, fingers crossed.

Stew

[potty]

Got the last bit of soldering done this morning with John.

First up the foundation ring which is made from 1/4" square copper rod, just cut and file to fit, to stop the bits falling into the boiler when evering expands on heating we simply drilled 1/16 through the outside and into the ring and put some copper rivets into the holes, you don't hammer the rivets over just place them in so they act as pegs. Everything was given a short pickle and clean and a good fluxing and rods of solder placed over the joints with a double dose at the corners, and some flux on the solder, the fire box was filled with thermalite block to keep the heat on the foundation ring. I had a pic of this but deleted it by mistake :doh: . Then with two butane torches we applied the heat it took quite a while for it to get up to temperature then as the solder melted we added more solder to fill the joints, when it looked OK let everything cool a bit then a quench in water and a pickle, this is the results.





Next we did the two bushes on the side of the boiler for the feed clacks, sorry no pics.

And the last soldering job for the boiler was the boiler tube plate, similar procedure as before this is the set up before soldering, rings of solder arround the flue tubes and arround the outside of the plate.



Two torches again with more solder added as melting temerature was reached.

We had to reheat and resolder two of the flue tubes as the solder had failed to flow into the joint.

This is the final result.



Well hopfully that all the soldering done, I've got to make some blanking plugs and fit the longitudinal stays before I do a pressure test, that will be in a couple of weeks as I'm still waiting for a calibrated pressure gauge.

Fingers crossed for the pressure test.

Stew

Well That More or less brings you up to date I hope the saga of my trials and tribulation are of interest to this forum.

Stew

[Shawki Shlemon]

When there is a will there is a way , well done , nothing will hinder your progress .congratulation .

[redmog]

Stew.
Thanks for sharing your photographs and the progress report.
I very much enjoyed reading through it.
It's nice to follow someone elses approach.
I should be getting on with my V4 boiler but keep delaying fetching some 5/32" copper rivets for the stays until I have a longer list of material requirements.
Good luck with the hydraulic test.
I know too well how frustrating it is to have to remove the blanking plugs to repair an annoying leak.
Chris

[potty]

Thanks for your comments Lads

Mike I used a boiler kit from Reeves it cost £300 but If I was to build another boiler I wouldn't got that way again I'd source the material as seperate bits this would save money, and the flanged end plates that were part of the kit had a real poor finish I ended up making formers so that they could be tidied up.

I must have put about £50 worth of solder in it and used about £20 worth of gas and say another £50 for flux rivets etc.

The boiler is for LBSC 3 1/2" 2-4-0 Mabel I've got the frame and wheels done, the cylinder and motion work and I've tested it on hair and to me it runs well.

Cheers

Stew

[mutley]

nice work so far. Any pictures of it finished?

Andy

[potty]

Andy

I havn't cut the stays off yet I was leaving that until I'd done my own high pressure test as fixing leaks with the stays long is easyer.

This is a pic of me doing the low pressure test.


I'll post some pics of the boiler being tested at 2* working pressure when I get it done.

[mutley]

Great, just wondering as you had implied all the soldering was done but there was no sign of bushes on the backhead or front tube plate.

Andy

[chiptim]

Nice work Stew and great pictures. You make it look simple!!
Good luck with the testing.
Tim

[bruce]

Thanks so much for sharing your progress! Nice job! It gives us beginners the confidence to get up and do what has to be done.