Figured out a trick for forge welding thin stock without it burning up

I kept losing the edges on 1/8 inch steel when trying to weld it at my shop outside Dayton. Last Tuesday I tried a flux mix of half borax and half iron filings like an old timer showed me at a hammer-in. It held the heat steady and the weld took on the second pass instead of the fifth. Anyone else use a special flux blend for thin material?

2 comments

2 Comments

tylerr391mo ago

Yeah man that flux mix really does the trick, @martin.vera is spot on about plain borax just running off like water on thin stuff. I had the same problem with 1/8 inch trying to weld up some scrollwork brackets and kept getting these crispy edges that just flaked off. Then I swapped to a 60/40 mix of borax and fine steel dust I saved from my grinder and it was night and day. The iron filings seem to thicken it up just enough to stay put where you need it and it really holds that heat in the joint way better than straight borax. I've been telling everyone at my local guild about it and they're all switching over now too.

martin.vera1mo ago

Oh, I just had to laugh reading this because I still remember the first time I tried forge welding thin stock and ended up with what looked like a burnt-up potato chip with handles! That flux mix of half borax and half iron filings sounds like something worth trying for sure. I've been using plain borax forever but it just seems to run off when the steel gets too thin. An old blacksmith I knew used to say you can tell a real pro by how they handle the thin stuff without turning it into cinders. I might have to dig through my scrap bin for some iron filings and give your blend a shot this weekend.