Boiler Build

[kno3]

The more I look at your boiler building skills, the less inclined I feel to build my own boiler, as silver soldering seems to be a lot of work on these large pieces.

[potty]

Cheers Derek I enjoyed the time I spent with my Dad.

kno3

Don't be put off having a go at boiler building the important thing is preparation and taking your time, since i've started my boiler I've not bin working at it exclusively managed to fit in some tooling work around it, if you've not done any silver soldering try experimenting on some small parts, getting the heat in the correct place is halve the battle you have to sneak up on the job with the heat try and avoid directly heating the solder heat from the opposite side of the job, that way the solder is drawn to the heat.

Any way 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]

Thanks Guys

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 brassed 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 intended, I wonder how many other builders have fallen at this 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

[derekwarner_decoy]

You know PD's.......... ...but I think that Potty & Bogs went to the same school for tech drawing  .....

Yes...some of the latest sketches here have that same distinct dimensional hieroglyphics "   \  ? # *  /

Yes & appear to be en-scribed to ciggy papers too  .....Derek

[potty]

Hi Derek

No we didn't go the same school but we were both shaken by the same steam hammers forging out loco axles  at Crewe Engine works,  we did grow up in close proximity to each other but never met until 18 months ago.

Stew

PS. I've never smoked I only use ciggy paper for edge finding 

[PeeWee]

Looking very good Stew,  its taken me awhile to realise but i have also been following this on madmodder 

[potty]

Thanks Derek/Ian

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.
 
 

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



 

[potty]

As it will be a couple of weeks before I can pressure test for real I was bitting at the bit just to do a low pressure test.

Before I go on just a warning so that no one gets the wrong message:- DO NOT CONNECT A BOILER TO A COMPRESSOR IT IS VERY DANGEROUS.

Ok what I did was make a connector for a bicycle pump, immersed the boiler in water and with a few strokes of the pump just enough to raise the pressure by a few PSI to see if there were any leeks, the only leeks I had were from the screw plugs for the regulator and the longitudinal stays which are easily fixed, there was nothing from any of the soldered joints:- so far so good.



Stew

[potty]

I've had this on hold for a few weeks, as I've been waiting to have some pressure gages checked out I'd acquired them over the years and was not sure if they were working OK and I didn't want to test the boiler with them not being sure if they worked. The guy who was going to check them let me down somewhat so last weekend I retrieved them.

After giving it some thought I thought the best thing to do was to make a manifold so that I could compare the gauges one with the others (I've four to choose from) that way a faulty gage would be eliminated by the other three.

I connected them to the boiler feed pump I made, like this looks a bit heath but it worked.



I couldn't get the gauges to tighten so that you could see both faces.

But this is what I got.





They were all different scales but I was able to detect that one gauge was reading 20 PSI light so that was dumped the other three were Ok and gave similar readings with each other.

Tomorrow will know be the big day:-I'll fix a couple of leeks i've got with the screw coupling on the regulator and one of the screwed longitudinal stays, then it will be fingers crossed.


This will be own test if all goes well I'll cut the end off the stays off and submit the boiler for official inspection.

Stew

[potty]

Well I sort of tested the boiler yesterday, I took it up to 40psi there was a leek from the inside of the hollow blower stay, so I gave the nut a tweak, when ping the bloody thing broke.



 

So did a bit of investigating the drawing calls for 5/32*22g copper pipe I was supplied 3/16*22g pipe as part of the boiler kit which I turned the end down and threaded 5/32 * 40 which had the effect of thinning the wall of the tube down that and being one turn short to tighten the nuts down resulted in overloading and the break. So I've got to order some 5/32 pipe next week before I can conduct the test again. On the positive side as 40 psi there was no signs of any other leeks.

Stew

[potty]

Well I tried the hollow stay twice more with the same result ping it broke, there is very little wall thickness left after the thread is cut, plan B, use a solid stay and run the blower around the outside of the boiler.

Today i took delivery of a solid stay, it didn't break but a I still had difficulty getting the threads to seal I tried ptfe tape but the joints just kept weeping, next try to seal them with copper slip.

I did get it up to 160 psi a couple of times and it held pressure long enough for me to check out all the soldered joints and they were all good, I'm now going to cut off the spikes and book the boiler in for a test with the inspector.

 




Happy Stew

[potty]

Thanks Guys

I repeated the test this morning using copper slip to seal the threads it worked great.



I then cut off the spikes and cleaned the boiler up with a brass wire brush.

Then I couldn't resist seeing how it looked between the frames



Starting to look like a proper loco now.

Stew

[morris3@fas.harvard.edu]

Just wanted to post my thanks for this excellent series!  I'm (March 2012) studying up on boiler-building as I'm working on a 3-1/2 ga. Baltimore & Ohio P7 Pacific, #5300 "President Washington" -- just arranging to buy barrel tube tomorrow.  It was really helpful to see all the entire silver-soldering sequence in well-done photos, so clearly described.  They have done wonders for helping me understand book-reading (Harris, ME backissues, Farmer)   -Chris Morrison

(I got the castings from http://0187632.netsolhost.com/productsforsale/312gaugep7462.html)