Oil Quench Question

[Suicycle]

All the stuff ran through the oven at the shop is air hardening, unless it is a gov't project. The question is if I wrap a blade in the foil to prevent scale, do I have to remove it to oil quench? I am starting to fool with O1. If so how critical is the time from removal of heat source to quench? I know it sould be really quick. Also I realize a thin 1/8 to 1/4 inch thick blade cools a lot faster that thicker stock that we normaly run. Also any techniques on how to treat a blade to keep it from warping a considerable amount.

So far my first knife I used A2 on it and I wrapped it in foil with a steel dowel through the tang to keep it as close to edge up as possible. The first 3 blades I tried before looked more like a boomerang. Two of them were 4142 PHT that I tried to harden more.......didn't know what would happen. Those first blades were just flat stock ran on a manual mill with a tapered mill to form the master grind and then cut out to shape on a band saw. I drilled and reamed 1/8" holes to pin the scales on, just in case, and cooked them. It was all a learning process to the guys that run the oven to ht something that thin and long. The 2 blades that were 4142 came out in the high 20's, where they started out, and the A2 blade the guy cut the tip off with his scissors, but it was around 58 to 60 RC. I tested the middle of the blade and about 1/3 up from where the cutting edge is and also the tang area.

I considder myself lucky on the 4th blade, that became my first finished knife. I just don't want to throw a lot of labor at a new steel type to be disappointed. I have several knife blanks ready for the oven and would like to do them all at once. I would prefer not to make one and try untill I get the procedure correct. I know the O1 coming straight from the furnace to 85 degree motor oil will give me something in the area of 60 to 62 RC on our testing machine. That was done last week on 1/2" square stock to test the cool motor oil, and see how bad the scale would be.

[mete]

For air hardening steels the convenient way is to plate quench. Remove the blade, still in the foil, and clamp between two plates. Use 3/4-1" thick aluminum. This might work for some of the oil hardening ones .I was hoping that someone would try it with the oil hardening steels. PLate quenching eliminates warping , messy oil, and gets it hard.

[Suicycle]

Wow that search button is handy. I did a little reaserch on plate quenching and found a good bit of answers on the foil and time till quench on O1. Oddly enough. Even got educated on how to straighten worped blades, if they are not fully hardened. Seems like a good reason to edge quench my knives.