LBSC Green Arrow

8

29/12/2021

Apologies for the lack of updates but it's not been a good year, what with one thing and another, and I just haven't felt like doing a great deal recently. Hopefully, that will change in the new year!

So, to catch up -

The frames were painted outside using the spray can of satin black and the insides painted red by hand.

 

The wheels were then all hand painted with Doncaster Green from Craftmaster Paints which is my prefered supplier. They are considerably cheaper than that other well known supplier of model paints and perhaps better suited to brush painting. The only downside is that you are limited in the size tins that you can buy. In this case I had to buy a 1litre tin but it was the same price as 250ml from the other supplier. I will be painting a lot of future locos in Doncaster green!

I did have trouble getting the paint to cover on the wheels and ended up having to apply three coats. I suspect this was because I hadn't used the correct colour undercoat which is dark grey. I used the Upol Acid 8 primer which is a very light grey. It's also possible that I hadn't stirred the paint up enough before I used it.

Once the wheels and the cylinders were painted I could start assembling the chassis again. I also spent quite a bit of time cleaning up all the motion before refitting it and it came up looking nice.

 

 

It was now that I discovered a problem that hadn't shown up before. The front coupling rod bosses were hitting the crossheads. I wondered why this hadn't happened before and then realised that when I ran the chassis on air before I had not fitted the coupling rods. The solution was to remove the cylinders again and mill a clearance on the back of the crossheads.

 

 

Assembly could now continue until the chassis was all back together again.

 

 

I also machined some front covers for the cylinders from aluminium bar which finish them off nicely.

 

 

The motion was quite stiff now which was not surprising as things never go back exactly as they were originally but after running on air for a bit it soon freed up again. I did revisit the timing and tweaked it a bit as it was a bit out after the reassembly.

I realised now that I should have refitted the cylinder cladding before I had painted the cylinders because I will probably have to make new cladding and will probably scratch the paint on the cylinders getting it to fit. However, I decided to move on to the boiler next and see what that was like. If it was scrap and I had to replace it, the project may have ground to a halt there and then! I don't think that I could have faced having to make a new boiler for it.

Onto the boiler then.

The first job was to remove all of the fittings and the boiler cladding to get down to the bare shell.

That was easier said than done. I removed the screw that held the dome cover on but the dome refused to budge. It turns out that it had been soft soldered to the cladding! Then the cladding had been soldered to the boiler on the throatplate and the backhead, obviously to hold it in place. Judicious use of heat from a small gas torch soon had it removed though to reveal the boiler in all it's glory. The 'insulation' under the cladding was just some thin cardboard from a very old box that had contained some unmentionable ladies product!

The boiler actually looked quite well made and neat and tidy so I was hopefull that it would be usable.

 

 

The backhead fittings all have bushes except for the blower valve which threads onto the end of the hollow blower stay. The hinges for the firedoor are screwed directly into the backhead which is fine but the screws are probably brass. I may replace them with some bronze ones if possible.

 

 

The centre stay at the bottom of the backhead has been drilled and tapped for a bolt that I think holds a latch to retain the dropping part of the grate. Unfortunately, a steel bolt had been used that has rusted away.

 

The smokebox tubeplate is not so pretty and seems to have a large amount of soft solder around the tubes. I would guess that there may have been a few leaks there when the boiler was initially tested and the builder just put loads of soft solder on to cure it. I'll clean it all up and see what it's like after that. The tubes are definitely silver soldered so I can't forsee any problems. The fitting for the superheater header threads into the tubeplate and I think that it was the gasket between that and the superheater header that was leaking badly when I first tested the boiler. I'm not sure what the screw is for in the bottom of the tubeplate.

 

 

The regulator is a sliding block type as per the LBSC drawings and I don't hold out much hope of it sealing very well. At the moment though, I can't see an easy way to remove it. The regulator body is held to the boiler barrel by a countersunk screw in front of the dome bush that has been soft soldered over to seal it. Even if I remove the screw, I still don't see how to get it out of the boiler! It obviously went in there though, presumably after the boiler was built.

 

 

The firebox has the LBSC combustion chamber so fingers crossed that there are no leaks in that! The firebox and the stays all look fine. I just hope that the stays are not brass. If they are, I'll just run the boiler until they start to fail and then replace them. As they are threaded and soft soldered that would not be too big a job.

 

 

After a good clean up the boiler started to look pretty good. There are a few splodges of soft solder on the backhead, mainly around the blower valve where it has been sealed and also around the firedoor hinges to seal the screws.

 

 

I would guess that the solder used would have been something like Tinmans solder. I doubt that Comsol or similar would have been around at the time that this boiler was built.

The shell and the stayheads look very nice.

 

 

The front tubeplate is definitely the worst part but I think it will clean up ok.

 

 

After making up some brass blanking plugs and refitting the dome cover it was time for a hydraulic test to twice working pressure - 160psi for 80psi working pressure.

This turned out to be much better than I was expecting with only a few very small pinhole weeps - a couple on the blower valve where the soft solder hadn't taken properly, one on the top of the firehole ring, a very tiny leak on the wrapper on top of the back head where it looks as though a screw had been used to blank off a hole, and both the stays on the front tubeplate had tiny weeps. Nothing bad at all. None of the firebox stays leaked and the combustion chamber was fine, much to my relief. I was surprised about the stays as I was sure that a couple had shown leaks on my initial test but they were bone dry now.

So, it looks all good for the boiler. All it needs is a few spots of soft solder to cure the tiny leaks and we should be good to go.

I will be replacing the cladding as the original was steel which is showing signs of rust. It will have to be repainted anyway as the original paint got well and truly scorched where I had to use the gas torch to remove it! A shame really as the paint and the lining on the boiler bands had been very nicely done.

So that brings the rebuild up to date. Hopefully, there will be more updates in the new year.

 

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