| tubes
Hi
Another quick one just showing the firetubes being fitted in the tube plates for teh first time.
As a matter of course now on every copper boiler I make I flare one end of teh tubes to prevent them dropping through during silver soldering the firebox wrapper. trust me loosing a tube as you are soldering the firebox wrapper is a real pain in the backside and one to be seriously avoided. The little flare will stop this from happening and allow you to reposition any tube that moves during soldering with ease.
The flare should not be any larger than is required to stop te tube dropping through the hole. Also the flair should be inside the firebox and not allowed to extend into the water space.
Each tube is 20 gauge seamless copper tube, dont ever be tempted to use plumbing tube it just isnt designed to take the pressure!
The holes for the tubes are counter to good thinking cut slightly loose for the tubes to fit in. I start at a 5 thou over size hole. This sllows the silver solder to fill all around the tube and not just form a ring on one face of the tube plate. This is a very important factor in soldering the tubes in.
The first picture shows a raw tube unmachined, second picture shows a dead center being used to form the flare on the tube end, third picture shows the lite flare on one of the tube ends.
The fourth picture should give an idea of what the tubes will look like once inside the boiler. lats one is a view in through the fire hole ring.
Cheers Kevin |