Building a Boiler for a 3 1/2" Gauge Locomotive

[shoey51]

great work Stew
cheers Graham

[sbwhart]

Thanks Chaps

I think I've got it sorted in my mind know which way to go, I don't like to jump in when I've got problem like this I like to let them sit for a bit so I can think and weigh up my options.

Rob:- yes I made that foot for the vernier this is the thread. http://madmodder.net/index.php?topic=1800.0 I've used it a lot the other end it cut away for marking out.

Stew

[Dean W]

Glad you were able to get back to it after sorting things out, Stew.
The tip about using a "tickle wire" is a good one.  Would be really handy
drilling in close cross holes where a guy doesn't want little divots inside the tubing/pipe.

Thanks!

Dean

[Brass_Machine]

Nice work Stew!

Eric

[madjackghengis]

Glad you were able to get back to it after sorting things out, Stew.
The tip about using a "tickle wire" is a good one.  Would be really handy
drilling in close cross holes where a guy doesn't want little divots inside the tubing/pipe.

Thanks!

Dean

Amen to that bit of info, it seems like a very useful technique to avoid pits where they can't easily be fixed, will definitely be useful lots!  Nice work on the working out of the rear of the fire box, and resolution of the interferance.  A typical case where the reduction of something in size in three dimensions has irritating aspects in the two dimensional aspect of surface area when it comes to fittings and external fitments.  Nice job on the stays and the soldering as well, top notch all the way, I expect this to be a real work of beauty when it is finally steamed up.  I enjoy the attitude of a "new challenge" rather than the loss of composure, so often seen in our working world, but not necessarily in our hobby world, where we can throw away the error, and start anew, with more experience.  It has helped me in my world of work, and transferred over to a large degree, and I am far less frustrated in life in general because of knowing it is just a part, it can always be made again.  When done by someone with the skills shown by Dean, it inspires a desire to match it for myself for my own edification, if for nothing else.    mad jack

[sbwhart]

Thanks Dean/Eric/Jack

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

[Divided he ad]

Looking good Stew 



Fingers crossed.... it'll be puffing steam before you know it   


I was just wondering, as I know nothing of such things.... do you de-quill the porcupine before it's fitted to the loco?   






Ralph.

[sbwhart]

Hi Ralph

Yes the porcupine will be dequilled but after I've done a pressure test, it's easier to fix any leeks with the stays left long.

Stew

[shoey51]

Im glad you sorted out your problems there Stew.
its definitely a thing of beauty

Graham

[Dean W]

the penny finally dropped the error wasn't with the drawing but with me.

Doggonit!  I wanted it to be the other guy's fault.   

Glad you found the trouble and have it sorted out, Stew.  I'm cheering for you on you next inspector's visit!

Dean

[Stilldrillin]

It`s nice when the head scratching stops, and the penny finally drops........      

Well done Stew, for keeping it public. 

Hope all goes more smoothly from now on........ 

David D

[NickG]

Stew, it's looking brilliant - fancy doing another 1? haha! That will pass with flying colours. Was going to say the loco's nearly ready now but you've got still got the tender to do!

Thanks for sharing this with us.

Cheers,

Nick

[sbwhart]

Nick

If you're serious about making a boiler we're always on hand to help/advice, if you can get down for a day we can certainly get you started in the right direction.

But I wouldn't buy a kit I'd buy the material and form the plates myself it not dificulty at all and I've got the formers.

At the end of the thread I'll do a summary of the good and bad points of my experiences lessons learnt and what I would do different next time.

Stew

[madjackghengis]

Hi Stew, I don't know about you, but it is always a relief for me when I find out I made a mistake, because then I not only get to start the piece again, but I also get to use the ideas I came up with in considering the problem, and ultimately end up with a better part than I would have, had I got it just right, but still had to deal with interferance and other issues.  From the looks of your latest pictures, you've got a top notch boiler which is going to be a sturdy and strong one and will serve the engine it feeds, well for a long time.  It's always possible to scab over a crack, and get by with a less than elegant fix, but such things always come back and haunt, so the re-make, always faster due to experience, and always more accurate, because you know all the tidbits of interference and issues of other sorts which matter, and can compensate as you go on the final round.  I'm really looking forward to the finished boiler, post inspection, ready to put steam to the engine, and prove out its own value by performance.  You've done a great job at showing all the details, and have made me forever forget the idea of faking a boiler for my steam engine, because making a real one is tedious, but not hard, just demanding care and close attention to detail.  Great looking boiler there, thanks much for the lessons in steam engineering.  mad jack

[sbwhart]

Thanks Jack sorry if its bin a long time answering.

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  . 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



 

[Stilldrillin]

Blummin well done Stew! 

Fingers firmly crossed on your behalf...... 

David D

[shoey51]

fingers crossed here for ya Stew great work mate

[NickG]

Fingers crossed Stew! Well done, it looks spot on. 

When I took my boiler down to the club ages ago they wanted to see the longitudinal stays soldered in too. They usually are, I know the 1 on the left looking from the front is a hollow stay for the blower. The strange thing about it is, the blower valve goes straight into the backhead without any bush - but they weren't happy with that on mine for some reason.

Nick

[sbwhart]

Thanks for your good wishes Lads, just spent a couple of hours making blanking plugs for the pressure test still got a few to go. I spotted that one of the stays in the back head, fire box side, didn't have any solder around it, so thats causing me some concern, its towards the front so it can be got at, we will see.

Nick:- I've followed the drawing with the longitudinal stays where they are screwed onto the end plates, talked to the boiler inspector about it and he was open on screwed or soldered, sometimes I think these thing are left open to interpretation, I know there is an issue with boiler valves being able to be screwed all the way out, where there's a bit of an ongoing debate in Model Engineer. I sure you've come across this at work it all boils down to professional judgement in the end, but it can get very frustrating.

Stew

[Dean W]

It looks very well done, Stew.  I hope the inspector feels the same way I do!   
Thanks for the new pictures and write up.

Dean

[sbwhart]

Thanks Dean

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

[Stilldrillin]

A gentle test, and the results are just as I expected, Stew! 

Blummin well done!       

David D

[spuddevans]

Looking good there Stew 

I've been really enjoying this build, thanks for documenting it for us all to see and learn from.


Tim

[shoey51]

well done Stew

[madjackghengis]

Hi Stew, as so many others have said, well done, and beautiful.  Your posting has been clear enough I feel confident in being able to take a set of boiler plans and build a boiler properly, and have a successful one, using raw stock and my own pick without a kit, and I've never wanted to spend the money on the kit.  I am just a bit surprised in the fact you did not do a hydrostat test yourself.  given that you have all the fittings in place, I assume you have the gauges you will be using, as well as other, higher ranging gauges, and you will be using a mechanical feed pump, you ought to use it to do a true "hydro-stat test", with the boiler in a container you can readily establish a reasonably precise level static, and then pump it up to the standards that are the norm for boiler inspectors, and watching the level of your water the boiler is immersed in.  I've never done such a thing with a boiler or a steam apparatus, but I have done this to test a hydraulic accumulator and other hydraulic equipment I've had cause to repair, to ensure no incipient cracks are waiting to emerge, and my understanding from my reading, is this form of test would give you a definitive idea of how much distortion the boiler will go through, physically, when it is "up to steam" and where such distortion will show its self.  Please don't take this as disparagement, but only as a serious question, hoping for a definitive answer.  I can't reiterate how valuable I have found your post to be, and how much it has impacted my own intents for the future with regard to building boilers, you have literally taken that stainless steel "boiler" I found inside a carpet machine and relegated it to nothing but a test object, and forever closed it out as an actual operating devise because of both the quality of your workmanship, which I believe I am up to, and the quality of the post, which has eliminated all my questions and guesses which have arisen out of my studies of model boilers I've made for future intents. mad jack