I'm sure it will be a lot better than my first attempt with a gas solder torch some years ago - my previous experience had been using several different electric soldering irons but these are generally ineffective for repairs on Mamod brass work.Narrow Minded wrote:it aint gonna look pretty
This is actually one of the silver soldered boilers that Mamod produced at the end of the original railway system and I was trying to build it up around the steam dome insert - left the solder on for too long and it just flowed and flowed and flowed!
I assume that you are talking about the tube through the middle of the boiler through which the steam pipe goes up into the steam dome nut. In my experience all my boilers have been fitted with a thick walled tube/pipe there which has had the bottom end machined so it just sticks out proud below the boiler (i.e. there is no gland as such or a rivet as others have previously thought). Thus there is very little contact with the boiler on the inside and that solder paste joint is a very common failure even when using solid fuel tablets (it is right above the middle fire tube on the common 3 wick meths burners).
If you recall back in my MSS Kit build Topic I showed how I had improved that joint by scrapping away a small amount of the paint around the joint, roughening up the surface, applying flux and then getting the solder to stick. You will end up with too much solder there to start with to get an effective seal but it can be cleaned up with filing and fine wet and dry sandpaper.
Here is my workshop donor boiler. This was an old SL riveted boiler won on eBay which I totally paint stripped, soldered the steam dome insert, soldered in 2 x 6BA nuts at the front to replace the method of using posidrive screws with 6BA screws, soldered in 2 x 6BA screws into the rivet holes on the boiler back to allow the sight glass/boiler back plate to be held in using 6BA washers & nuts, and soldered up that weak joint on the bottom of the boiler.
I cleaned up that solder again by using files and fine wet and dry sandpaper plus lots of polishing and this boiler is very steam tight. I've also read elsewhere that removing the paint from the boiler underside increases the efficiency of heat transfer from your burner to the boiler.
There has been an unusually large presence of Mamod railway items on evilBay recently including a few of these back plates. Otherwise there are several traders on-line who sell them as MSS spare parts.dougrail wrote:anyone got a spare brass boiler back plate?
Chris Cairns.
but if it's worked, then wow 
