Coal vs propane heat treating, finally saw the difference

I ran a coal forge for 12 years in Lancaster, PA. 4 months ago I switched to propane for hardening chisels and punches. Coal gave uneven spots, always guessing the color. Propane holds a consistent band, I nail 1450°F every time now. Anyone else make the jump and fight with their old tempering habit?

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max47221d ago

The real game changer is how propane changes your quench timing, not just the heat. With coal you're always chasing the color and you end up quenching by feel, sometimes too early or late. Propane lets you hold that temp steady, so you can actually watch the soak time and pull it out at the exact same moment every batch. That consistency is what kills the old habit of second guessing yourself. After a month on propane I realized my tempering was off because my hardening was always slightly different, not because my tempering process was wrong. Once you lock in that repeatable start, everything downstream falls into place.