Bad Blade

[DANA HOLMAN]

Fellows
I need some help. My last post that had the two knives, the one that had the bocote handle had a spot in the edge, thought i might of hit something with it, so last night i resharpen it and could not get it razor sharp, i then found that the edge was soft,
This blade was heated and quenced and tempered for 2-2hr cycles, then i noticed the blade was bent, so knowing what happened to the last one, i anealed the blade again, and the blade warped like crazy, i had to put in on the anvel and beat it stright, after that i reheated and tempered it, (the same as always).
I've tryed to take the edge down alittle but it's still soft. I've done something wrong, but i don't know that, If i take it down anymore the knife will not look right. I don't think i can heat the edge up to harden it with out screwing up the handle        
any thoughts
dana

[LAR43]

If you can disassemble it, take the handles off & re heat treat it right from the beginning. Depending on the steel you used, sounds like something's gone wrong in your heat treat process. Make sure you're bringing it up to the correct heat for quenching. Some steels just won't harden. That's why it's a good practice to use steel that you know it's composition.
I'm sure Lin or Karl or both will add something to help you out.
It's all part of the learning curve.

Larry

[DANA HOLMAN]

Lar43
the steel is 1095, what is strainge is the othe knife that is the brother to this one, is from the same steel, i can replace the handle but the bolsters are the problem, i know that i've done something wrong, maybe lin and karl will jump in
thanks dana

[Lin Rhea]

Dana,
          What oil did you quench in? Lin

[Jeremy]

1095 is real touchy when it comes to quenching in oil.  You either need to have one of the high dollar, fancy, proper fast quench oils, or be spot on with your temperature and get it into the oil FAST.

I know mineral and corn will work, but you need to keep the blade on the smaller size and pay real close attention to the temerature of your steel.  They just can't cool off a bigger or thicker blade fast enough.  I couldn't get motor oil or transmission fluid to properly harden any of the test blades I tried.

Ideally with 1095, buy a proper quench oil.  If not, you need to be very careful and aware of the limitations of the oil you're using to get consistent results.

I get good results with corn oil and "regular" blades 4" and under.  I know I can go up to 5" blade if it's thinner and shorter if I leave the blade real thick.  If I go outside of those specs I need to be very careful of what I'm doing or I won't get consistent results.  Trying to harden a bowie sized knife out of 1095 in anything other than a proper quenchant or water isn't going to happen.  I've experimented enough to know the limitations of the materials I'm working with.  I'll go through the same tests when I finally do get a proper quench oil too, just so I know what will and won't work.

[DANA HOLMAN]

Lin/Jeremy
I'm useing veg oil, like when i was making them with O1, i know i need parker AAA but times are a little tough, i also know i need to get some 1080 or 1084, or 5160 steel, just have not had time to put my blower on my forge, because all i can find is 1/4" steel in 5160.
It just seamed strange that the other knife is fine, it came from the other end of the steel,
this steel is some i bought from Jantz's 1 1/2 x1/8 x18" flat bar,
i would take the bolsters off but i think i would just screw them up,and the handle would be toast, just neded to make a new one
thanks dana

[Lin Rhea]

Dana,
       Jeremy's right, in my opinion. 1095 needs a fast oil. Have you tried mineral oil? I just hardened a 10 inch blade of 1095 with an equal mix of light wieght oil, deisel, and ATF, with a pint of mineral oil in for whatever reason. It hardened the blade very well. The only problem is that it flames up pretty bad, but I just try to be careful while quenching. I might mention the blade is 5/16 thick at the ricasso. So, it is pretty hefty. Lin

[Jeremy]

Interesting mix Lin!

The addition of the diesel raises the specific heat of the mixture some, but the real benefit should be from thinning the mixture to aid in the convective heat transfer.  Try swapping the diesel out with 100% ethanol - should work a little better without raising the pucker factor any more.

Gotta say, I never considered adding something like diesel!

[Jeremy]

Scatch that EtOH... got to thinking about it in my sleep last night and although it would raise the specific heat more than the diesel and help with the heat transfer, the temerature at which it vaporizes is lower so you might cancel out any benefits.

Dana, P#50 would be the correct choice for 1095 if I remember what Karl was saying; it's close to the quench speed of water.  AAA is a slower quench oil.

I don't have much left in my supply of 1095... thinking after it's gone I'll switch over completely to 5160 (I have a bunch) and 1084 and get some AAA.  Course I haven't had any time in the shop for knives in months!!

[DANA HOLMAN]

Guys
thanks, for all your help, i think what i need to do is, step back and regroup, stop making knives until i get what i need to do it right, (oil,forge, knowhow) i'm not in this just for fun, someday i'll be a J.S., it maybe years from now, but someday it will happen.
lin, i will see you at the hammer-in, and will be full of questions( if you don't mind)
dana

[Lin Rhea]

I look forward to it Dana. Bring that brother of yours if you can. Lin

[DANA HOLMAN]

Lin
i think he will be in McAlester ok. for a draw hunt. but i'll check
dana