Brian- Another practice is to build up a lump of brass (this could be in a joint of two tubes or on a surface) maybe 1/8" high. Then using the flame go around this lump and flow it out bit by bit. I find I turn down the flame after flowing the joint (to get an internal fillet) before I go back and lay the fillet down. I'll add brass along about 1/2" of joint length, trying to keep the brass humped up (not trying to get it to flow out and look like a final fillet) then go back and work this length of lump out onto each tube surface. With a small flame you can get real close to the joint but be willing to back off, flick away, the flame often to control how hot things get and watch out where the tail of the flame is going to not ruin what you've already done. Andy.