Author Topic: Calbourne - 5" gauge boiler  (Read 6826 times)

Offline Keith1500

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Re: Calbourne - 5" gauge boiler
« Reply #75 on: February 14, 2023, 11:57:09 AM »
I am amazed that tube got damaged in the first place but as you said if it drew the heat through it for a hit too long… so credit to you for highlighting it as a honest mistake for anyone else to note when doing a boiler.

So glad you came up with a neat fix. I wouldn’t have thought to do the hole and plug. Nice one.

Keith

Offline internal_fire

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Re: Calbourne - 5" gauge boiler
« Reply #76 on: February 14, 2023, 05:10:49 PM »
I am amazed that tube got damaged in the first place

Propane/air flame temperature is nearly 2000 C at its hottest point. Copper melts at just over 1000 C. Typically there is so much heat loss in a copper asembly that it is hard to melt the copper with a propane torch. However, when the copper is small (little conduction), in still air (little convection), and enclosed (little net radiation) there is plently of opportunity for reaching a melt condition.

Gene

Offline vtsteam

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Re: Calbourne - 5" gauge boiler
« Reply #77 on: February 15, 2023, 01:47:50 AM »
Glad you made the repair Steve.  :cheers:

Building new things always presents difficulties to surmount, and doing that adds pleasure to the final success.  :popcorn: :popcorn:
Steve

Offline springcrocus

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Re: Calbourne - 5" gauge boiler
« Reply #78 on: February 15, 2023, 09:23:54 AM »
Thanks to everyone for showing an interest in this thread.  :)

On the home straight now. After fixing a couple of dodgy stays, we then went on to fit the backhead. Prior to that, I had dressed back the pipe end leading to the water gauge top fitting.



Bushes, firehole and most of the stays went without a hitch and there was a small area at the top of the wrapper that needed resoldering which didn't come to light until the boiler had been thorougly cleaned. During the heat-up, the solder resting on the lip fell off and I had to resort to the dab-it-in method but this is generally not very successful for amateurs like me and Wilf. At the next session, we tidied up the backhead, then gave it another session in the pickle while we had lunch.



After lunch, we started on the foundation ring but I didn't take any pictures of the infill pieces, unfortunately. I had made all the parts earlier in the week so it was just a case of fluxing up, setting them in place and teasing the wrapper for a nice fit. The small holes near each corner were filled with copper shards or sections of copper wire, beaten flat. I have some ribbon-style silver solder that had been given to me and was told it was Easyflo, so pretty similar to our usual stuff. Here is the set-up in the hearth.



The foundation ring pieces are set just below the level of the outer wrapper so it's like a shallow moat all the way round. There's actually quite a lot of solder there because the stuff is 5mm wide x 1mm thick. I had filed a chamfer on the outer edges of the four pieces to encourage the solder to flow down the gaps. Here's another view from further back showing how much effort we go to setting things up. This is all to conserve heat but also keep it mostly where it's needed.



We started with two normal burners but kept blowing each other's torch out so Wilf went back to the cyclone burner and worked inside the box while I heated the outside. Once we were nearly up to temperature, we concentrated our efforts at a single point on one of the sides, then slowly worked our way round chasing the melting solder until we were back at the start. That was it, finished.



It looked like a pretty good melt but it's always hard to tell until the thing has cooled and been cleared up. Immediately after that last picture was taken, a further block was placed on top to slow down any localised cooling. I allowed it to cool for about thirty minutes before washing and pickling. This is the result and it can be seen that it's gone well. All the solder has vanished instead of puddling on top and all the gaps are a lovely, shiny silver.



It looked like there was a tiny gap at the back of the foundation ring so we re-soldered that just to be sure of a seal. After cooling and pickling, we bunged up all the bushes and started to pump. We had all the usual weeps from the blanking plugs but once we had got that settled down, we wiped everything dry and took in stages up to 160 psi. After twenty minutes pressure was still just over 150psi but everything was bone dry so it was probably just leaking back past the pump.



After that, I dressed back the crown stays and the extra firehole stays to make it look pretty in preparation for it's official shell test up at our club. This is the completed boiler.





The boiler passed it's shell test (2x hydraulic) on 23rd November 2022 and the loco will, hopefully, be completed during 2023.

People rarely record details of their mistakes, preferring to gloss over these and just show the successful bits. I think people learn more from their mistakes than their successes and it's sorting out the problems that make this hobby so interesting. If it was easy, it would be boring. I hope you enjoyed sharing my journey.

Regards, Steve
« Last Edit: February 15, 2023, 09:29:02 AM by springcrocus »
Member of a local model engineers society
www.stevesbritannia.co.uk

Offline MJM460

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Re: Calbourne - 5" gauge boiler
« Reply #79 on: February 15, 2023, 11:00:19 AM »
Beautiful work, Steve.  You and Wilf have done an amazing job.

I am glad you documented it trials and all.  There is so much to learn in how these problems are solved.

Great news that it passed the hydro test.

I guess the steam test must wait until you have safety valves, grates, blowers etc. but I hope you will continue writing about the engine in the mean time.

Liking forward to the next chapters.

MJM460

The more I learn, the more I find that I still have to learn!

Offline FKreider

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Re: Calbourne - 5" gauge boiler
« Reply #80 on: February 15, 2023, 01:18:14 PM »
You make it look easy! (those of us who have done any silver soldering know its not!)

 Thanks for sharing!
-Frank K.

Offline vtsteam

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Re: Calbourne - 5" gauge boiler
« Reply #81 on: February 15, 2023, 01:22:12 PM »
A great series, well illustrated and explained. A fine boiler out of it, and great explanations for anyone interested in copper work, silver brazing, and boiler making. Thank you Steve for taking the time to record it all here.  :NotWorthy: :NotWorthy: :ThumbsUp: :ThumbsUp: :cheers:
Steve

Offline RReid

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Re: Calbourne - 5" gauge boiler
« Reply #82 on: February 15, 2023, 02:52:56 PM »
An excellent story well told, warts and all! And out of the smoke and ashes comes one mighty fine boiler. Well done! :cheers:
Regards,
Ron

Offline flying fox

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Re: Calbourne - 5" gauge boiler
« Reply #83 on: February 15, 2023, 04:45:58 PM »
Well done Steve, good looking result.
Regards
Brian B

Offline Admiral_dk

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Re: Calbourne - 5" gauge boiler
« Reply #84 on: February 15, 2023, 05:15:28 PM »
Thank you very much for a great write up - that illustrates the majority of how, why and what can happen  :praise2:

Per                 :cheers:          :cheers:

Online Kim

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Re: Calbourne - 5" gauge boiler
« Reply #85 on: February 15, 2023, 05:54:25 PM »
Congratulatoins on a beautiful boiler, Steve!   :ThumbsUp: :popcorn:

And thank you for taking the time to document the whole build on the thread here.  I really appreciate it.  I've learned a lot from reading this and I'm sure many others have too.

I hope you'll continue to share your locomotive build with us here :)

Kim

Offline Mike R

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Re: Calbourne - 5" gauge boiler
« Reply #86 on: February 15, 2023, 08:24:49 PM »
Nicely written up Steve.  I'd rather not call them mistakes but learning experiences at least the first time for any particular item, a 2nd time - ok maybe that's a mistake!  :wallbang: . I've had my share of both and expect many more!  It is appreciated that you share yours with us, whatever they're called!
« Last Edit: February 16, 2023, 01:51:20 AM by Mike R »

Offline crueby

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Re: Calbourne - 5" gauge boiler
« Reply #87 on: February 15, 2023, 09:05:42 PM »
Not problems, but opportunities. Glad you didn't run into any Insurmountable Opportunities!

 :ThumbsUp: :ThumbsUp:

Offline Firebird

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Re: Calbourne - 5" gauge boiler
« Reply #88 on: February 16, 2023, 10:08:03 PM »
Hi Steve

Thanks for the great write up.  :ThumbsUp: :ThumbsUp:

My mate and I have 2 Sweetpea boilers to build shortly so the tips have been of great value

Cheers

Rich

 

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