More sticky foil

Phil705

Phil705

Basic Member
Joined
Aug 23, 2007
Messages
364
There was a good thread a little while ago that offered suggestions on how to avoid stainless foil from sticking during and after HT. I bought some 309 SS foil, sprayed the knife with WD40, wrapped it once (not twice), double folded the edges, and baked the sucker at 1950, held it for 50 minutes, and plate quenched in the foil with one inch thick aluminum plates.

The results were the worst sticking I have experienced! What the bleep am I doing wrong? I have a hard time believing that not double-wrapping is the issue, but I am open to all suggestions.
 
I agree with Rusty,I think your putting too much pressure on it,I use 1-1/2" plates and just set one on top of the other and use hand pressure for about a minit.It will some time stick but all I have to do is cut the end off and twist the blade with a pair of needle nose pliers and it comes free.On cpm154 I also use 1950 deg for a 45 min. soak so I don't think it's time or temp.
Stan
 
You could be right. I have been clamping the plates moderately thinking that that might help reduce the risk of warping. I won't clamp next time and see what happens. Thanks. Any other ideas out there?
 
What steel are you using? I find that plate quenching can give some undesired results! :) But that's just me...some people swear by it!
 
I have been plate quenching 154CM, CPM154, S30V , and A2 with good results, although I can't swear to hardness without a Rockwell tester. My latest foil disaster was 154CM steel.
 
Hi Phil: I would not spray with WD40. Use talcum powder next time. 50 minutes seems like a long soak for 154CM.

RJ
 
I used to plate quench A2, but with some of the chisel grinds i did, i found that the steel would want to warp from cutting edge to spine (like a katana!), on the thinner stuff 1/16", 1/8"....so i retired my plates and now just take them out of the oven, wait till all the visible red heat is gone from the packet, cut them open, check for straightness, straighten if needed, and then hang to still air cool. Still gives a hardness of 65-66 from the still air quench. For A2 temper at 500' for 2 hours each time and it will give a hardness of 60-61.

I have (in the past) had 321 stainless weld itself to the blade slightly, but nothing major. I have used 321 from Lyon Industries for some time now and a blade has never welded *yet*. before I was using 321 from TKS.
 
I am gonna try the talcum powder next week. It's real easy to crank down on the vise when trying to be quick. Something I need to work on also.
 
I'll also try talcum powder next time and nix WD40, and I won't clamp the plates so hard. But I love plate quenching, it works for me, and it's cleaner for my shop. Thanks for all the replies.
 
I Have been clamping my blades in my Kurt vise with a set of aluminum soft jaws. Works great for me . I'm also gonna have to try the talcum powder thing , Thanks RJ ! I used 2" thick steel plates for years but there heavy, i'm lazy and the vise just makes sense. I only bust out the plates if I'm doing a dozen or more blades.
 
If you are still having problems, I would change foils. Not all foils are created equal. I have used foil from www.sentryfurnaces.com for years now. It is not the cheapest, but it is very, very good! If you order from them, please mention my name. They are nice folks to deal with.

I did a batch of CPMS110V blades a few weeks ago. High temperature soak. Forgot the talcum powder. Foil stuck. I was pissed (at myself!).

I stand on my plates, FYI.

The way I see it, the sticking can only be caused by two things-Chemical bonding or mechanical locking. Chemical bonding would have to do with the foil. Mechanical locking would have to do with the finish of the blades. I used to scrub my blades with liquid soap and dry them in an oven. This tended to increase the foil sticking. Now, I just wipe them clean. I would think that if you had coarse scratches from a new belt that the mechanical locking could be a problem. I like a max grit of 220 before HT.

Try the talcum powder-It works for me at temps of 2100F with the Sentry foil and there is no evidence of foil failure at that temp, even though it's rated for 2000F. The blades look a little different (different shade of gey) with the powder, but that is the only effect.

RJ
 
thanks. If I still have problems after I use talc powder I'll try another type of foil. It was 309 SS and not cheap! And if that doesn't work, I'll try standing on my plates.

Thanks to all responders!!
 
I just got done using talcum powder and it's awesome! One plus is the powder on the fingertips soaks up a little sweat so you do not slip when folding the edges. WD 40, the other way around. I went into the baby's room and dug out one of the 87 bottles of baby powder and read the back to make sure it was 100% talc. That bottle will last me for the rest of my life.
 
i have welded foil on but onnly at high temps and not using the high temp foil

i use a 12 ton press to clamp my Al plates so i dont think most the time its a problem with too much pressure making the weld
 
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