| On copper I use oxyacetalin and a large propane torch to keep the barrel hot.
I never use braze only easyflow 2 silver solder. Still have to work to keep the heat in especialy on a 5.5 inch diameter traction engine boiler.
Rodding in on boilers isnt a great idea its always better to cut and lay bits of solder on the joints and let the heat flow into the joint.
Mind you its a real pleasure welding a boiler after soldering the last one.
Kevin |