I'm totally new to this knife making thing. I built a charcoal forge in my back yard. My intention was to anneal some files so I could grind them down then heat treat. I fired it up for the first time last night and it worked pretty well. From reading online, I got the idea that to anneal I needed to heat the steel up to critical temp, then let it cool slowly. I got the forge running, then put the steel in and brought it up to orange shading toward yellow, then turned the air off and put a couple of fire bricks over the top of the charcoal pile and let it burn down overnight. When I came out this morning to check out the result, all but one piece of my steel had warped. They started straight, but now have a bend in them. I did hit the pieces with a file and they seemed to have softened somewhat. Several questions arise out of this experience, maybe too many for one thread. First one, what happened to make the steel warp? Second, what do I need to do to straighten it back out? Third, what should I do differently next time to make sure my steel doesn't warp to begin with, and gets annealed properly?
-
The BladeForums.com 2024 Traditional Knife is available! Price is $250 ea (shipped within CONUS).
Order here: https://www.bladeforums.com/help/2024-traditional/
Warping?
- Thread starter Jason Fry
- Start date
- Joined
- Sep 27, 2004
- Messages
- 3,041
I'd guess uneven heating/cooling. Were they laying on one side and did they warp all in the same direction?
- Joined
- Apr 14, 2006
- Messages
- 3,816
JK
By your description your heat was probably a bit on the high side. Get a magnet and bring the material up until it does not stick any longer then one color change above. It should be in the red to light red-orange range. This does depend upon ambient lighting so the magnet is the best way to check. Next leaving them in the forge to cool is not the best either. Make an annealing bucket. A box (preferably not flammable) fill with vermiculite, dolomite lime, wood ash or the like. Put the hot blade into the insulating material after the critical heat. This will support and cool slowly without the problems associated with leaving it in the forge. Just the weight of the steel sagging in the forge at heat can cause warpage. To straighten first check to see if they are annealed, if you can file them. If you can you can make a straightening fixture for a xise and straighten them out cold. I recommend getting a couple of books to learn more about HT and annealing. The books I recommend are Wayne Goddards books "The Wonder of Knifemaking" and " The $50 Knife Shop". Great Basic Info.
By your description your heat was probably a bit on the high side. Get a magnet and bring the material up until it does not stick any longer then one color change above. It should be in the red to light red-orange range. This does depend upon ambient lighting so the magnet is the best way to check. Next leaving them in the forge to cool is not the best either. Make an annealing bucket. A box (preferably not flammable) fill with vermiculite, dolomite lime, wood ash or the like. Put the hot blade into the insulating material after the critical heat. This will support and cool slowly without the problems associated with leaving it in the forge. Just the weight of the steel sagging in the forge at heat can cause warpage. To straighten first check to see if they are annealed, if you can file them. If you can you can make a straightening fixture for a xise and straighten them out cold. I recommend getting a couple of books to learn more about HT and annealing. The books I recommend are Wayne Goddards books "The Wonder of Knifemaking" and " The $50 Knife Shop". Great Basic Info.