Is there some secret to make fillet welds with gas? I can never melt the root of the joint, and if I get enthusiastic with the torch I get holes through the pieces. By now I can make passable butt, corner an lap joint welds, but fillet defies me.
I've done this with some fairly heavy stuff(no stick welder), I was joining some channel to some angle iron for an engine dolly, the root was probably 1/2" thick. I found that you need a LOT of heat, 1 or 2 tip sizes more than the tip chart calls for. It's easy to crank the gas down on a big tip, but with a too-small one, once you get it turned up too far, it just blows the metal around and makes it tough to do a good job. Goes through the tanks fast, too. I'd never done it before so the beginning of the weld was pretty nasty, the end looked pretty good. Got the angle grinder out, grooved out the bad part and redid it and it looked pretty decent. You have to keep the flame longer on the thicker parts and if you let the molten pool cool too far, it's a bugger getting restarted. I don't have good electrical service in this rental place, probably stick would have been the way to go if I'd had the resources. Would certainly be cheaper. There's a usenet welding group that would probably have some better technique recommendations, I just play with things until they work for me, changing one variable at a time. Keep your tips shined up, the radiated heat from the corner makes it easy for the tip to pop out if it's dark and dirty.