Stainless foil sticking to blades

A

Adam Reese

Joined
Nov 4, 2010
Messages
400
Hi everyone!

Ok, I heat treated 6 440C blades last night and after they had cooled from the quench plates, when I went to cut them out of the stainless foil, on three of the knives (three chef's knives) the foil was stuck to the blades. Most of it peeled off, but there are a few spots where it is like the foil is fused to the blade. This was my regime:

All of the knives were 440C from Aldo. They were finish ground, then cleaned with alcohol while I was wearing gloves to prevent contamination, then places into the 309 stainless foil. I heated to 1400, held for 10 mins, then ramped to 1900 and held for 30 mins, then pulled them out and then plate quenched them. I got a Rc of 60 to 60.5 ish on every blade.

I have only done 4 440C knives in the past, and I know my temps were a little different, but I don't recall having this issue with them.

Anyone have any ideas why the foil stuck to the knives? Is it normal? I don't do a lot of stainless, so I'm not sure.

I was thinking maybe my oven doesn't seal good enough and O2 gets in and causes the foil to oxidize so bad that it is sticking to the blade?


Any insite would be great!
Thanks,
Adam
 
The foil may not be rated for the temp you are hitting. I had this problem as I was right on the border line for the foil I was using. I switched to the higher temp foil and so far I have not had any sticking.
 
Like Daniel said, you may not have the correct foil.

In addition, try giving each blade a light dusting on both sides with baby powder before putting them in the pouch.

Works great.
 
Thanks for the replies guys

I thought I had bought the higher temp foil, but it's been so long ago that I bought it, I may not have...

Robert, thanks for the tip about the powder, I'll deff try that next time. Does it make a difference whether it's the talc kind or cornstarch kind?
 
Talc is stone and handles the high heat.


Someone mentioned that you can buy it as talc in the dollar store, no other scents and additions that may discolour .
 
Adam have you ever considered using turco instead of the stainless foil? I use it on most of my blades now. It is kind of pricey but me Scott and Andy went in together and bought 5 gallons last year. I haven't even used half a gallon of it yet. Just something to consider.

I haven't used 440c in a long time, but I always used the 309 foil and never had any sticking problems. My ht procedure was pretty much the same as yours too. Even the 321 foil is rated to 2000 degrees so I'm not sure why that would be happening.

Jarrett
 
Jarrett you'll have to tell me more about that turco. I hadn't heard of it. After last night and cutting my hand to pieces with that stainless foil, I wouldn't mind paying more for something better!
 
The turco is a liquid that basically does the same thing as the stainless foil. I don't consider it to be any better, but it is definitely easier to fool with in my opinion. You just dip the blades in it and let them dry before you ht them. They won't come out of the oven looking as clean, but they clean up easily.

There were a few guild members interested in getting some the next time Scott places an order. If you'd like to try it give him a call so he knows your interested or if you want to buy a whole 5 gallon bucket for yourself Scott can tell you where to order from. It will last for years.
 
The fella that got me started in knife making uses it. He pretty much only uses 440c and I haven't heard of him having any problems. He says he uses it because it's cheaper than foil.
 
Adam, sorry for the delay in answering........ been out of town all day.

I just use plain old Johnson's Baby Powder. Never had any problems whatsoever.

Robert
 
I'd also like to add that I clean the blade and foil( inside) thoroughly with acetone while wearing rubber gloves.Thanks Lu
 
+1 on the Johnsons baby powder. Knives slide out of the foil really smoothly. There was no discolouring other than from the heat.
 
You must log in or register to reply here.
Back
Top