Anyone with experience heat treating 1080 blades in a kiln? How bad is the decarb if you do it without foil? How do you get the foil off and the knife in the oil fast enough if you only heat to 1450? The first one I tried I used a packet, but it was too cool by the time I finally got it into the oil. The second time I tried that blade bare and it worked well. Hit it with a file and it didn't seem to cut at all.
1080 blades in a HT oven
- Thread starter jkf96a
- Start date
Josh Dabney
Moderator
Jason,
I'm not working from a wealth of info here, just a couple blades I've done so far.
I chose to leave some extra meat on the blade so grinding off the decarb isn't a big deal. Takes a little time an patience at the grinder but by the time I grind to final dimension decarb is not a worry. It will be a little ugly out of the quench though.
I didn't use any scientific testing means to check blade performance but I did chop on a palm stump and chop an oak 2x4 nearly through and she still was shaving sharp so judging by those "tests" I'd say I got a pretty good heat treat this way.
-Josh
I'm not working from a wealth of info here, just a couple blades I've done so far.
I chose to leave some extra meat on the blade so grinding off the decarb isn't a big deal. Takes a little time an patience at the grinder but by the time I grind to final dimension decarb is not a worry. It will be a little ugly out of the quench though.
I didn't use any scientific testing means to check blade performance but I did chop on a palm stump and chop an oak 2x4 nearly through and she still was shaving sharp so judging by those "tests" I'd say I got a pretty good heat treat this way.
-Josh
Since I first posted this, I've heated and quenched 5 bare blades. The scale is worse than in the charcoal fire, but the HT seems to be going well, nice even gray color. I have noticed that the side of the blade that is down, the scale doesn't pop as well. Maybe something about the floor limiting oxygen access, or causing uneven temperatures. Haven't put any on the grinder yet, but preliminary file tests look good.
silver_pilate
Well-Known Member
It's a good idea to set the blades up on their spine in the oven. I just took a small piece of soft fire brick and cut a groove so that the blade rests on the brick and is held on spine by small uprights of brick on either side. In other words, 99% of the blade is still exposed to the oven atmosphere and not insulated by the brick. This little block also holds the knife off of the oven floor and makes it easier to grab with tongs to take and quench.
1080 series steels need to get quenched too fast for a foil pack to be of any practical use. You just don't have enough time to get the blade out of the packet. The only way to prevent scale is to use some sort of wash or anti-scale coating or heat treat in an inert (like argon gas) environment. Many makers have had good luck with a thin wash of satanite thinned with water. PBC powder works well if used correctly.
As for heat treating, scale is something you just deal with when heat treating oil quenching steels unless using some sort of antiscale as mentioned above. The scale is usually very thin, and you can easily remove it with a few minutes at the grinder or even with sandpaper.
--nathan
1080 series steels need to get quenched too fast for a foil pack to be of any practical use. You just don't have enough time to get the blade out of the packet. The only way to prevent scale is to use some sort of wash or anti-scale coating or heat treat in an inert (like argon gas) environment. Many makers have had good luck with a thin wash of satanite thinned with water. PBC powder works well if used correctly.
As for heat treating, scale is something you just deal with when heat treating oil quenching steels unless using some sort of antiscale as mentioned above. The scale is usually very thin, and you can easily remove it with a few minutes at the grinder or even with sandpaper.
--nathan
Rusty McDonald
KNIFE MAKER
I know a few tricks with carbon steels in a HT oven.
you dont really need PBC or Anti scale coumpound if you follow this tip
As soon as your done quenching and the blade can be touched with out burning your hand off, take some scotch brite and use some of the quenchant to scrub off the scale at this point it is still soft and will come off very easy.
Keep the tip away from the coils to prevent overheating of the thinner parts. I put mine pointing to the door of the Oven.
you dont really need PBC or Anti scale coumpound if you follow this tip
As soon as your done quenching and the blade can be touched with out burning your hand off, take some scotch brite and use some of the quenchant to scrub off the scale at this point it is still soft and will come off very easy.
Keep the tip away from the coils to prevent overheating of the thinner parts. I put mine pointing to the door of the Oven.
Josh Dabney
Moderator
Rusty.
Thanks for the tips ! Ever had an issue with messing up the tip of the blade with the tongs ?
Currently my tongs are a pair of linesmans pliers with conduit handle extensions and they'll leave some nice teeth tracks on the tang of a hot blade
-Josh
Thanks for the tips ! Ever had an issue with messing up the tip of the blade with the tongs ?
Currently my tongs are a pair of linesmans pliers with conduit handle extensions and they'll leave some nice teeth tracks on the tang of a hot blade
-Josh
Rusty McDonald
KNIFE MAKER
I use 2 sets of tongs. Cap tongs to pull them out and box tongs to grab the tang.
silver_pilate
Well-Known Member
For a long time, I used good old long reach needle nose pliers. Then I switched to a set of large concrete nippers that I modified to hold blades by grinding down the cutting edges of the pliers. Now I've got a set of wolf jaw tongs, and they work much better than anything I've used.
--nathan
--nathan
Rusty McDonald
KNIFE MAKER
Rusty.
Thanks for the tips ! Ever had an issue with messing up the tip of the blade with the tongs ?
Currently my tongs are a pair of linesmans pliers with conduit handle extensions and they'll leave some nice teeth tracks on the tang of a hot blade
-Josh
I should add that I only do this on longer knives that don't fit in my HT oven the way I would like. My oven is 13" deep so on an 8" blade with the tang being 5" I turn it around so the tip doesn't get over done as it were. and this is just a precaution that I take. it may or may not help but I like to think it does.
Anything bigger than this and I would use my forge.
