Dont need filler rod for tig welds?

admin

i was watching that show american chopper, and they were using the tig welder with out the filler rod. would it work just as well with long stitches without filler rod. or just like small tac welds
Reply:as long as your fit up is nice and tight, and metal is precleaned, you can do nice fusion welds without filler rod.  not recommended for structural joints or anything, but for cosmetic passes or welds not under any load, you can produce nice work.
Reply:Depending on the material, straight fusion can be as good (or better) than a weld with filler. Low carbon steels will generally fuse fine, as well as some stainlesses. Other stainlesses will crack out, precipitate carbides, or lose their corrosion resistance without the proper (generally different alloy) filler. Most aluminum grades need filler, as the weld will crack if done autogeneously (<--long word for no filler  )  but there as are some that  can be fused just fine.There is no reason  a properly prepared and performed weld without filler can't be just as good as one with filler in many materials. Filler makes it EASIER to do a good weld, though, as you have more versatility in joint prep, the ability to do thicker material, makes it easier to control the heat affected zone and burn-through (the filler cools the weld pool)  If you arn't sure what the exact material is, using a filler with known properties allows you to control the joint properties better.