How to soft solder?

[Wineman]

I learned to soft solder from my grandfather (born in 1894). He liked using soldering coppers (looks like short fireplace pokers with a fat head). We would heat them on the kitchen stove and you could solder 36" of thin metal until it was too cool to keep working. In the garage, he had a brass plumbers "furnace" basically a white gas pump up burner to heat them. He also had an electric iron about the size of a road flare. That would work quite well but once he was doing a rain gutter and the 100' 12 gauge electric cord ran out of amps to get it hot enough. My teen years as a "Pool Boy" we used Acetylene hand torches (American torch) for up to 3" copper pipes. That made a big difference. Propane would not work past 1.5" copper. We never used MAPP so I have no experience. I never soldered anything but sheet steel. Galvanized was tough, but a real acidic flux was the key. The most fun was the hard coal forge about the size of a small suitcase. Get that going and he would make chisels, hardened washers and yard tools. Ah, to be a kid again...

Dave

[Woodsy]

The steel must be bright and grease/oil free, use a good acid flux, use a decent sized copper soldering bolt, warm the steel with the gas, apply the flux, heat the copper soldering bolt (also fluxed) until the colour begins to change to a rippling light blue, tin the bolt with the solder and apply to the warm fluxed steel ensuring that the part is well tinned. Repeat for the second part. Clamp both parts in correct alignment and heat until the joint runs. Trim and refinish when cool. Use only tin/silver solder for parts that will be hot blued. Easy-peasy!

[Dannyboy53]

Fascinating thread with very good info. My thanks to all!

[AlexRod85]

i use water spray to cool off the a rag the spray i dolder twicein the roll