Robb, I tried once to use Mapp gas to silver solder a boiler. I almost got the right temp. but not quite. When I added a propane torch heating the boiler body, then the solder flowed under the Mapp gas torch. I just lit the Propane torch, pointed it at the boiler tube and blocked it into place with fire brick, that way I had 1 hand to hold the Mapp gas torch, and 1 hand to hold the solder against the joint.
Now I have a Presto-lite Air Acetylene torch that works for all my silver soldering needs. I got it at a flea market for 20.00 USD and here in Columbus Ohio, I got a tank swap out for around 35.00 USD. I'd say Royce has the right of it, put down the flux, unite the parts and put the solder along the joint, then heat the joint on the backside (away from the flux/solder) and wait for the solder to melt and flow into the joint. Good luck Terry Griner Columbus Ohio >>> [EMAIL PROTECTED] 07/10/03 10:23AM >>> Hi Robb. > Can an Oxy/acetylene torch be used to make a 2 ½" boiler? From what I have read, oxy/acetylene is too much heat for our purposes unless you are welding. > I see in my > local paper a fellow has a used one for sale tomorrow at his garage > sale. And I think that the turbo torch (acetylene only) torches are different than O/A torches. You can't just turn off the oxygen. > > I have tried the two fisted Mapp gas method Well, I had acetylene in my right hand. > but I need about two more > hands for flux and solder. And I use the method of fluxing (with black for boilers), laying on snippets (or rings) of silver solder, and heating until the solder flows into the heat (joint). You don't need to "scratch". In my experience, if you've reached the "scratch" point, the process has failed. royce in SB
