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
