Tig Welding gun parts - Tig welding is very useful and precise enough to repair many small gun parts that you just cant buy.
In this video, Larry Potterfield from Midway USA, explains how tig welding is used to repair hard to find gun parts. The example he uses is on a small steel part that has been repaired using the brazing process. The braze did not last and before attempting tig welding , the braze material must be removed before rewelding. Otherwise the Zinc in the brass will make the weld outgas and will make a weak and ugly weld. Once the braze material has been completely removed with either a file or dremel tool or both, the part can be aligned and tack welded.After tack welding the cracks can be grooved out with small carbide burr and rewelded with either E70s3 tig wire (you can even strip off a little mig wire like E70s3 or E70s6 and it will work fine) or er502 or er309 stainless tig wire. er502 is the strongest, (even though it is sometimes referred to as 502 stainless, it is really more like a tool steel) followed by er309, followed by E70s2. But strength is not the only factor. If the weld needs to be filed the E70s2 is much easier to file.Make sure to add the minimum amount of filler rod or you will spend more time filing and grinding than welding. Tig welding is a precise and economical way to fix many gun parts.
Some good advice is to use a small electrode for these precise jobs. a 1/16" tungsten electrode will be much more precise than a 3/32" electrode in starting and controlling the arc. You will most certainly need less than 100 amps for doing the kind of repair depicted in this tig welding video.
One concern is that most gun parts are made from tool steel or high carbon steel. That means that when it is welded , precautions need to be taken to prevent the welds from becoming hard and brittle. Small parts should not require a preheat but slow cooling is a must. Only use a hardenable filler rod when maximum strength is required and consider a post weld heat treatment to restore ductility if you need to use a hardenable rod like er502.