Heat treat problem

[Wedgy]

Hi all just started knife making using AEB-L and Nitro V. I had a problem with the 2 knives I made around the 6inch length when I heat treat them the last inch closes the door comes out crusty black and not hardened the rest of the knife is fine the 2 smaller knives about 4 inch are fine. I use the S/S foil and try to fold the edges pretty well the kiln is a new Paragon. The first 6in I put a small piece of paper in the foil packet the second I didn't add anything but same result. Would anyone have a idea what I am doing wrong. Sorry no photos I never think to take them until it's to late. Thank you for your time . Dave

 

[Daniel Carraher]

It’s hardened. That’s decarb and it’ll be hard under the decade if you grind it away. Oxygen is getting through on the one side, how many times are you folding sides?

 

[Wedgy]

Thanks for your reply Daniel All Folds are double and tapped flat and have been new foil. Cheers Dave

 

[Stacy E. Apelt - Bladesmith]

TIPS:
Try making the foil packet a tad bigger. You are probably tearing a minute hole in the end fold.
Use a wooden mallet to tap the folds securely flat.
Be careful putting the packet in the oven that you don't puncture the foil with the tongs. DON'T use pliers! Use smooth jawed pick-up tongs.

As Daniel said, grind it down and it is likely OK.

I don't use paper or any spray, just tightly folded foil.

 

[Wedgy]

Hi Stacy thanks for the tips I do use pliers and the problem is always on the end I hold with them . Cheers Dave