Found out a weird trick for forge welding from an 1800s book

I picked up this old blacksmithing manual from 1872 at an antique shop last weekend. There's a section where they talk about using a specific kind of sand for flux, not the borax everyone uses today. The author claimed you could weld wrought iron at a lower heat if you mix in a little charcoal dust with the sand. Tried it yesterday on some scrap and it actually stuck together cleaner than my borax welds. Has anyone else messed around with older flux recipes from way back?

2 comments

2 Comments

alice3361mo ago

My grandpa was a carpenter and he always said the old ways work better for a reason. It's kind of like how I've noticed people nowadays overcomplicate things with all these newfangled products when the simple stuff from our grandparents' time did the job just fine. That sand and charcoal mix probably works because it's stripping impurities in a more natural way, not just coating them with a chemical layer like borax does. Bet you that old-timer knew exactly what he was doing and didn't need a bunch of fancy lab tests to figure it out. Makes you wonder what else we lost when we threw out those old recipe books.

lucaslee1mo ago

I read somewhere that the silica in the sand reacts with iron oxide to form a glassy slag that actually pulls impurities out, while borax just kind of floats them to the surface. Some old timer told me once that the charcoal dust creates a localized reducing atmosphere right at the weld line, which is why you can get a good bond at lower temps. Makes sense when you think about it - those guys weren't stupid, they just didn't have fancy lab equipment to explain why their methods worked.