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Warning about forge welding without a proper flux barrier
I keep seeing folks at the local guild meetings try to weld high carbon steel without a good flux, or with the wrong kind. Last Tuesday, a guy was trying to weld a piece of 5160 spring steel for a knife and just used borax from the grocery store. It bubbled off way too fast and left a ton of scale, so his weld was full of holes. I learned this the hard way about a year back when I ruined a perfectly good truck leaf spring trying to make a hatchet. You need a proper welding flux made for the job, something that melts at the right temp and stays put. It makes a glassy layer that keeps the oxygen out while the metal is hot and sticky. If you skip that step, you're just burning money and time. What's your go-to flux for welding tool steels, and have you ever saved a piece after a bad flux job?
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blakefox1mo ago
Why are we acting like store borax is the problem and not just poor heat control? That 5160 weld failed because the guy got it way too hot, not because of his flux. I've welded plenty of spring steel with plain borax when I ran out of the fancy stuff, you just have to work faster and keep the temp right. A good smith can make a clean weld with less than perfect tools. Seems like blaming the flux is just an excuse for rushing the job.
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brian3031mo ago
Alright, but here's the thing. If a guy is already struggling with heat control on a tricky steel like 5160, isn't using a subpar flux just making his job harder? Sure, a master can do it, but for most of us, good tools cover for a little skill gap. Isn't the real point that using the right flux gives you a bigger safety net so a small heat mistake doesn't ruin the whole weld?
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