copper plate for quenching- source?

koyote

koyote

Joined
Mar 29, 2007
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I had a long talk with one of the Californian ABS masters this weekend about quenching in my slab slided blades, and pregrinding versus doing the whole scandi or scandivex grind after heat treat....

So now I'm looking for some copper plates. I could go for the full 1 inch thick and 4 or 5 inches by 12, or I could go with 1/2 inch and use some of my steel plate to back it with. Either way.....where do I find it?
 
Okay. Guy I was talking to mentioned having tried brass, titanium, steel, and copper over the years and having copper work best.


He didn't mention aluminum...how fast will that cool? I'm game to try it.
 
Copper is faster than Aluminum at conducting heat. It is also WAY more expensive (about 3X the cost).
Aluminum is what I've seen most knifemakers mention for queching plates.
 
Pure copper has about 1.7x the thermal conductivity of pure aluminum -- and about 2.7x the thermal conductivity of aluminum alloys on average (plus copper has a heck of a lot more mass per volume -- much higher heat capacity). If you can get some slabs of copper in those sizes without breaking the bank, it should definitely get the job done.

IIRC, lots and lots of copper plates were the original secret that allowed Gillette to perfect the whole mass market volume heat treatment without warping to create the cheap disposable razor blade.
 
Check out Inudstrial Metal Supply, a lot of scrap copper cut offs in good sizes.
 
Before anyone posts about running to the bank to get $500.00 in pennies to melt down ( they aren't copper anymore), lets stop and think about what the quench plates do.

They replace AIR in the quench. Now, while copper has a much higher thermal conductivity than aluminum, aluminum has a vastly greater thermal conductivity than air. The aluminum will quench the blade more than adequately, since it would quench with no plates at all. The main function of the plates is in warpage prevention. This is partly accomplished by physical restraint, and partly by evenness of the quench. In both cases, aluminum is sufficient.

If someone called you up and said they had a huge block of copper that you could have for free, buy all mean say "Thank You" ,and go and get it. But, if you are going to the scrap yard or OnLineMetals to look for quench plates, look for some bars of aluminum about 1.5-2" thick ,by 3-4" wide, and 16-20" long.
BTW, copper is a B!#@H to cut.

Make some sort of simple clamping devise to hold the plates tightly to the packet when quenching. I use a pipe vise ( used to hold pipe while cutting and threading) that I bought at a yard sale for $3.

Stacy
 
Give a call to your metal recyclers. A lot of them sell 'sellable' metals for a little over what they paid for the scrap. I'm not 100% sure on this but I think aluminum moves heat faster than copper, copper will absorb it and hold it. Then again the higher mass of copper may be able to take more heat than aluminum. 'shrugs'
 
the concept of using metal plates for the quenchant is new to me... Is this considered 'fast' or 'slow'? In other words... what type of steel would this method be best for? Can anybody point me to a good resource for this method??

Thanks!
 
Metal plates are used to give a faster quench to air quench steels.

After doing some research I have found that copper is indeed a faster heatsink than aluminum, it's just a lot more massive. Had to wrap my brain around that especially the fact that you can grind two identical sized pieces of copper and aluminum and the copper will feel a heck of a lot hotter - which logically means that the copper is transferring heat more efficiently.
 
If you have never been to blue collar supply, check it out. They have tons of random stuff...maybe copper plates, but definitely aluminum plate in most thicknesses. It is in SE Sac on Florin.

-Mike
 
M.Griffin said:
If you have never been to blue collar supply, check it out. They have tons of random stuff...maybe copper plates, but definitely aluminum plate in most thicknesses. It is in SE Sac on Florin.

-Mike
Click to expand...

I'll be making a trip this week, it looks like. Never even heard of it, thanks!
 
Just my 2 cents, but I don't think you need anything "faster". It's already been mentioned that we are replacing air cooling, and even steel plates are a whole lot faster than air quench.

The advantages to plate quenching are that they help to keep blades from warping - and most of all..... when you quench in the envelope, the hot blade never sees air so they come out VERY clean.

I've read lots about fans and venting / cooling systems for quench plates - and that's great if you want to cool them down for the next batch - but there really isn't any advantage to superfast quenching of air quench steels. If there was, we'd be water quenching them. :eek:

Sometimes, there's too much of a good thing. KISS!

Rob!
 
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