Quench plates and Quenching questions?

[Tbonz]

I have been using two steel plates 12" X 12" X 3/8" to quench my 154CM knives on, my knives have an OAL of 9" . Is that a proper size to use for quench plates?
Does anyone have a preference for Aluminum plates over steel?
What type of material and size plates do you use?
How long does it take to quench your 154 CM or ATS 34 knives with plates? I remove them from the foil before quenching.
Does anyone use forced air to quench with?
Thanks
Tim

[Jerry Hossom]

One of the good reasons for using quench plates is so you don't have to remove the blades from the foil. That takes much too long and you want to get the steel temp down below 1000F ASAP. Quench them in the foil. Your plates will do that easy enough, especially if you're doing one blade at a time.

Forced air is pretty slow if the blades are in foil, and as mentioned above removing them from the foil is too slow too.

[rhrocker]

Tim, I did my first plate quench the other day, with some email help from RLinger. When I removed the hot pouch from the kile at 1850 (I was cooking D2), I didn't take the blade out of the foil. I placed it straight down on a large steel plate (like yours), then put another plate on top of that, then a 150 ob. anvil on top of that. All of this was done in under 5 seconds, which may have still been to slow, I don't know. I didn't try any forced air between the plates. Before it got cool (was still warm to the touch), it went back into the kiln, which was set at 500, for 2 hours (Did this twice, with a room temp cooling in between). There was no warping, and I got a Rockwell hardness of 61, which I think is ok for D2.

[Ed Caffrey]

I agree with Jerry.... the plates your using should work fine. I use 1" thick aluminum plates, but the only steel I ever use that requires an air quench is S-30V. I went with the Aluminum plates simply because I found them very cheap at a Boeing surplus outlet. I will also add my "yes" to leaving blades in the foil.

[RJ Martin]

Aluminum plates are preferred, simply because they conduct heat faster than steel. I use 2 1/2" thick AL plates and 1" thick AL plates. The 1" plates are larger in size, and even with a large packet of thick blades, they still do fine.
1/2" steel would be OK, provided you're not doing large batches of blades. You can cool the plates between uses in the sink with water.

WRT time to get the blades between the blocks: Think about it!!! With air hardening steels, you've got plenty of time, but, the faster you can get it done, the better. Under 20 seconds is fine!!!!!!!!!!! 5 seconds is perfect-it's virtually instantaneous as far as the steel is concerned.

DON'T TAKE THE BLADES OUT OF THE FOIL!!!!!!!!!!!!

It doesn't make anything better, and, it can only cause problems.

As quenched, Rc61 for D2 steel is fine.

[SteveS]

Me too on the 1" aluminum plates, leave in foil. I've used the air compressor and shot air between the plates, but I don't think that makes a difference. I do S30V and ATS-34.

Also, I don't put anything on top other than my hands. I press down for a minute. Then remove from the packet while still too hot for hands, but cool enough for gloves. If any straightening is needed I can do it right then. The steel is still bendable for a minute.

Steve

[rhrocker]

CL (Craig) Wilkins was in the shop a few days ago, and told me that they have a way to put the steel plates in a large vice, and clamp down on the foil pack when it comes out. I think there's a "lip" on the bottom one of the plates, so that the packet won't fall through, and can be slid or dropped into position, then clamped with the vice. I really like this method of HT'ing, vs. the oil quench (although I realize the importance of it also. I haven't tried straight air quenching.

[RJ Martin]

Robert: I stand on mine, and, "jump" up and down by flexing my knees. My feet don't leave the plate. You can increase the load on the plates by over 50% this way.

[Tbonz]

Thanks for the input guys. It seems universal at this time, quench in the foil.
I've only been doing one knife at a time so far, When you do more then one knife at a time are they sealed in the same foil pack or does each knife receive its own foil pack?
Thanks Tim

[mete]

RJ Martin, a "jump quench" , that's a new one on me !!

[rhrocker]

Mete said: "jump quench"

[SteveS]

Why the need for all the extra pressure?

Steve

[mete]

Steve, you really want full contact to conduct the heat away uniformly. That means no gap between quench plate and foil and no gap between foil and blade .I'd probably do it with a vise.

[SteveS]

Thanks mete. Hmmmm. I've just been leaning on it or putting a coffee can full of lead (20lbs) on there. That seems to make good enough contract. I thought maybe it idea was to keep it from warping or something. Also I try and keep the weight over the tang so I don't bend it over the distal taper.

Steve