Howdy ABS wizards
Maybe this is a question with obvious answers but I’d love to discuss the merits of different options/solutions.
I have found that Kevin Cashen’s interrupted quench technique gives me a near 100% success heat treating thinner blades without warps. I did one yesterday a 9” integral chef’s knife and when I interrupted the quench I saw a wiggle so I clamped it between 2 angle irons to finish the quench.
Here’s the thing- when I etched it was obvious that the thick integral bolster held enough heat to show a curved quench line in my blade/bolster transition.
It’s actually probably perfect for performance to have the transition softer but it’s a hidden tang chef’s knife not a heavy chopper so it won’t see that kind of stress.
And the pattern evened out some from a coffee etch after the ferric but I like all my fittings to match or at least to have control of the process.
Seems like I need to embrace the quench line/autohamon effect, or just forge thicker and grind more if I want meat there so I can safely stay in the quench oil long enough to get even hardness in an integral bolster.
Any comments or discussion is greatly appreciated!
Kevin Cunningham
@kevincunninghamknives on IG if you wanna see my recent work
It may also be that the thicker, heavier bolster area simply did not get up into austenite.
I wasn't there - so I don't really know. Are you austenizing with a forge or an oven?
Hardening/heat treating is a "dance" sometimes trying to get what you want.
You may want to have an oxy torch going at the same time to pre-heat the bolster area so as to have it the same temp as the rest of the blade when it gets ready - if you're using the forge for heat.
Just an idea.
Thanks Karl
I’m heating with a forge trusting color & magnetism. I gave the knife a good soak tang side first then flipped it to cycle the thinner blade in and out.
I’m 100% sure the integral bolster had a hard candy shell when the blade came out of the oil but that lump just couldn’t lose heat as fast as a thin chef’s blade that was only thick enough to sacrifice a decarb layer after quench.
Maybe I should just be super happy to have a straight blade and that the coffee etch evened things out a lot- the ferric etch left the bolster mostly gray compared to the near black of the hard 1084.
