I did it over a Coleman propane stove. If your stovetop has a high BTU burner, that would work better, maybe. The handle, btw, will get hot. Be careful. Scoured the inside of the pans with fine steel wool, then wiped several times with white vinegar. The acid etches the surface of the pan slightly so the solder will stick. I was afraid to use a stronger acid that might prove toxic. I bought lead-free silver bearing solder in the plumbing section of the local hardware store and cut about a foot of it into 1/2" to 1" pieces. Put them in the pan and heated it over the flame, moving it constantly. When the solder began to flux, I used the wadded chamois (wadded so it presented a smooth side to the surface of the pan) to wipe the solder around the inside of the pan, then turned the pan up so I could wipe the excess solder downward and out. Then set the pan aside to cool. The process is called "hot wiping," and is how copper cookware was tinned traditionally. I was nowhere near as good at it as the gentleman on National Geographic, but I got a better than adequate tinning job. A stronger acid than vinegar would probably make the solder flux better, but as I said, I didn't want to chance poisoning my pans. I don't think it could ruin a pan, as the process looks like it can be interrupted, picked back up or restarted from any point.