well thanks all for the feedback. I guess I should have gave a little more information. I am experianced in the plumbing soldering trade and I am using the same flux my solder is lead free and contains 4% silver also I am using my propane torch. But there is a problem with the heat thing I'm trying to solder a piece of brass tube to the end of my tailwheel gear just above the nylon mount and am afraid of melting the nylon. I've kept the nylon out of the flame but still have slightly discolored the nylon around the steel from heat transfer allready.I really feel that I have enuff heat but cant get solder to flow into joint.any more sugestions? thank-you all.