I'm in the process of soldering the cabanes and interplane struts on my 1/4 scale EAA Bipe (the Balsa USA kit). The cabanes and struts both extend through balsa into the structure of the plane. I'm using a torch to get enough heat to apply the solder, but I'm worried about the effects of the heat on the balsa and plywood structure. I don't imagine balsa would fare well when exposed to a blow torch (or even metal hot enough to melt silver bearing solder). The kit instructions say to use a heavy piece of paper to protect the wood, but that just doesn't seem like it would cut it. This wasn't really a problem for the landing gear because the solder joints are far enough away from the balsa that I could keep it separated.

I tried making a barrier out of an aluminum can, but that's a real pain, and I was wondering whether somebody might have a better way to do this. Any suggestions?

By the way, this is my first time soldering anything other than small electrical wires and an occasional clevis/pushrod connection. I tried various soldering irons and guns with various power ratings -- all without much luck. The little propane torch was the only thing that would heat the metal enough to melt the solder.