Took me three full days to figure out why my forge welds kept failing

I've been blacksmithing for about 4 years now and I thought I had forge welding down pretty good. Then last month I tried welding up a stack of 1/4 inch mild steel for a hammer head and it just would not stick. I kept heating it to the right orange color, hitting it the same way I always do, and every time the weld fell apart. I spent two days rechecking my flux, my hammer angle, even my anvil. Finally on day three I noticed a tiny crack in my fire brick near the back of the forge. That crack was letting in a cold draft that was cooling the back of my billet way faster than the front. I blocked the crack with some refractory cement and the next weld stuck perfect on the first try. Has anyone else had something stupid like a tiny air leak mess up their forge work for days?

2 comments

2 Comments

jenny_coleman24d ago

That tiny crack story hits close to home. I had a similar thing happen with my propane forge where the burner tube had a hairline split near the base, and it was sucking in cold air that made the heat all uneven. Drove me NUTS for a weekend because the front of the billet would look perfect while the back was barely warm enough to weld. I finally caught it by feeling around the forge with the back of my hand for cool spots, and once I patched it with a bit of high-temp tape, everything worked again. It's ALWAYS the dumb little stuff that wastes the most time, not the big obvious problems.

morgan_ramirez24d ago

Had a buddy chase a similar ghost for two whole days on his knife blades, turned out his garage door was cracked open just enough to swirl cold air into the back of his forge. He finally closed it and bam, every weld took like it was supposed to... drives me crazy how the smallest thing can wreck everything.