Ya know..there are some days...

[jph]

Gib:

Ok...just checking as alot of folks don't know what a double wedge is. As for the oil, that should work, as I use the same stuff with a few minor changes as you do. No need to buy that EXPENSIVE tempering oil when you can mix up your own that works just as well, if not better for much le$$.

Take care, let me know how they turn out.

JPH

[Gene Chapman]

Some where there was a post or article on loose hammer handles, the fix was to soak in antifreeze, it dosen't evaporate like a water soaked handle.

In the Pacific NW nothing evaporates, it's always raining.

[Fox Creek]

'cause I am having the same problem with skinny blades with a radical change in cross section (thick spined Scottish dirks) :confused: The dang things do a reverse sabering warp towards the edge. I suspect they are ground too thin going into the oil, but it is not a severe quench; I am trying hard to get an even heat and no hotter than necessary to harden. After all for pointy dagger , springy is appropriate temper I figure, so I am not trying to wring every last bit of hardness out of 'em. I almost e-mailed you private like, but felt sheepish. I have tried to think through it, and consider if a slower or faster quench would help, but concluded the edge is always going to cool much faster than the spine, and I figure its the contraction thats pulling it down. I have tried quenching them horizontally spine first in a trough of oil, and point first vertically, no difference. This is kind of a mystery to me, as the water quench Japenese katana blades warp the other way putting a desireable curve into the blades from my understanding of it.

[jph]

Howdy:

I don't have much problem with a dirk, are you heating up just the edge or are you doing the whole blade??

I usually just heat the cutting edges and go from there. How many fullers (if any) and how long/wide??

JPH

[Fox Creek]

..How many fullers (if any) and how long/wide??...

HT entire blade, not too big, aprox 12-1/2" long, 1-1/4" wide, about 1/4" thick at spine. Oh, no fullers ( a small swage and some file work on the spine though.)

[jph]

R.M.:

Gee at that dimension you shouldn't have any probles at all...how thick is the cutting edge when you HT? Too thin prior to thermal treatment is what it sound like to me..mine are between 3/32" and 1/8"...this is "as forged" dimensions as I get alot of my shaping done prior to grinding. In fact alot of folks say I get closer to final shape to forging than they do rough grinding..

Did you anneal prior to hardening???

JPH

[cactusforge]

Well I followed Jim's advice a long time ago and for what it is worth I forge to shape, normalize, profile, normalize two more times then heat treat, then do the rest of the grinding and have yet to have a warp. I have bent blades but very seldom. Before going to this process I was plagued with warping. I have used this on Toothpicks, Swords, Bowie's and Hunters. The steel I use is 5160 & 1084
Gib

[Dana Acker]

I forged a blade recently that took several tries to get the bend out. It was a big 5160 blade, and upon cooling after normalizing, it would bow, noticeably. I tried everything I knew to do, even counter bowing, and it would bow the same way every time. One time, out of the blue, it stayed straight. ????? Didn't do anything different that I know of. Anyway, Tai's vibration theory, along with planet allignment or lunar waves, not sacrificing a chicken or a virgin to Vulcan on time, something, I know not what, got me. Then, all of a sudden, with one heat and hammer whack, all was well. Normalized, quenched, and tempered, with no bow. Did the 5160 finally get the message, or could it have been the virgin thing? Some days you eat the bear....

Hey Jim, good to hear from you.

[Fox Creek]

jph.

umm. about 3/64" at the edge going into HT. Normalized before grinding. Normalized twice before hardening. The next one will be at least 1/8" you betcha! I think its a combination of too thin edge with the severely tapering profile that concentrates stress at the tip. .......... Dana, that's good advice. if it happens again I will re- do. I want to see what would happen when I get it back up to critical. I usually dont have warping problems(much), so have gotten complacent about grinding fairly thin going into the quench..... On the dirk blade in question, I shortened it and reground it to salvage,and it is working fine. It was very fine grained.

[Fox Creek]

I know 12 Inches or so is not a "long" blade, but it is right at the limit where it starts to be pain in the tookus to get an even heat in the coal forge. I have a perfectly good cast iron Propane burner with a hose and regulator, and a perfectly good high quality Propane tank so I think I see if I can rig up a long forge just for Heat treating.