Old timer told me to quench in warm water not cold, thought he was nuts

I was out at Rick's forge in Bakersfield last month and this old guy named Hank kept saying to use warm water for quenching. I laughed it off and stuck my blade in ice water like always. Ended up with stress cracks on the spine of a $150 chef knife. Next time I used 90 degree water from the tap and it worked perfect. Anyone else get advice from a crusty old smith that actually saved your hide?

3 comments

3 Comments

jade_grant951mo agoMost Upvoted

Why would you buy into old wives' tales when metallurgy is literally a science with data to back it up? Warm water doesn't magically fix stress cracks, it just masks the real issue like bad heat treatment or improper steel selection. I've quenched hundreds of blades in ice cold brine and never had a failure unless I messed up the soak time or the alloy wasn't right for the job. The old guard loves to blame temperature but they ignore how much technique and steel quality matter. You sure Hank didn't just want to sell you on his pet method to feel important?

ross.angela1mo ago

My buddy Dave tried that ice cold brine method once on a batch of kitchen knives he was making. He swore up and down it was the only way to get a good edge retention. First blade he quenched in it, ping, right down the center of the blade. He said it sounded like a bell ringing and then crack. He reset everything, checked his temps like five times, used a different steel, same result. Finally a guy at the local makerspace told him to try warm water, like 120 degrees, and he hasn't had a crack since. I trust the science too, but sometimes the old methods work because they handle real world variables better than a lab test.

robin83621d ago

@jade_grant95, you've quenched hundreds in ice cold brine and never had a failure if the steel and technique were right. So what specific alloy or thickness range are you working with where that's worked consistently? Because @ross.angela's buddy was using kitchen knives, which are usually thinner stock and different steel than a big chopper or a sword. Seems like the temperature argument might be more about what geometry and steel you're running than a one size fits all rule.