A lot of brass is not TIG friendly at all. There are a ton of different alloys, too. You have to really keep the heat down because of the zinc. I usually use DC, but Jody advises AC. I can't say his looked all that good, but I will try it some day. It's one of the few places where I try to keep the heat on the filler, and then wash it onto the base metal with just enough heat to get it to flow. Also take your time and let the part heat up, or preheat it. You don't want one spot really hot while right next to it is cool. Some alloys are porous and if they have soaked up oil or solvents, good luck! The best thing is to just let that stuff bake out if it will. If you need things to be leak free then you have your work cut out. There are also some fluxes that can help clean things up. Also you can braze it up for strength, then solder to seal any pinholes. For something like a petcock or hose fittings I usually just make socket joints and solder that stuff.
I once had a big job fixing a container of broken cast brass statues that were imported from India. Total crap brass and I think they just dug a hole in the ground to cast them in, as there was every kind of impurity imaginable. And of course to top it off the repairs needed to be invisible at least from the outside. Fortunately they all had an forced aged patina with liver of sulfur or something like it. It took me a long time to get a handle on welding that stuff. But once I got the technique down it really didn't take that long and the customer was thrilled with how they came out.
Long arc, short arc, heliarc and in-the-dark!
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Originally Posted by performance
