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Post by Deleted on Apr 20, 2008 2:28:19 GMT
well today i tried my first knife from 1095 high carbon steel. i tried my best to keep both sides even while grinding and they were more or less even. after getting the basic shape i annealed it 3 times the first 2 times i heated it up to non-magnetic and just took it out and set it to air cool and the third i took the air off the coals and let it sit in there for 3 hours then took it out to air cool. then i put a convex bevel on it leaving the edge about a half a millimeter wide. then i stuck it back into the coals and heated it to non magnetic while leaving the tang sticking out to keep it soft. i attempted quenching it in hot water and it cracked in 3 places. am i doing something wrong???
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Post by Deleted on Apr 20, 2008 3:50:54 GMT
Quenching in water for one:D. No need for the 3 normalising (not annealed, what you did was normalised) heats either, if it was stock removed you really only needed one, and SURELY you didn't need to let it sit in the coals for 3 hours (where'd you get that one?). SO much could have been wrong, temperature of blade, edge thickness before the quench, but most likely it was the water. It takes ALOT of expeirience and understanding to pull off a successful water quench, so be prepared that this will not be the first one you crack.
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Post by Deleted on Apr 20, 2008 5:41:05 GMT
well my understanding is that when heated the carbon molecule inter meshes with the iron molecule and when cooled SLOWLY more carbon molecules have time to escape the iron molecule further softening the metal but i could be wrong, just what my current understanding is. OK so on to the quenching part... i do know oil is a better but i wasn't sure of a few things and i felt water was a SAFER bet because it wasn't flammable. dont want the back yard to go up in flames. so what kind of oil can i use....when it bursts into flames what do i put it out with and when submerging it do i just dunk it in and hold it there until it is cool or do i do it in intervuls...i didn't have answer to these questions so i thought water would be my best bet.
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Post by Matt993f.o.d on Apr 20, 2008 19:23:05 GMT
Bad luck buddy. Try oil next time for the quench. Olive oil is slower at cooling than water, but faster than engine oil, and safer. It smells like cookies when you quench something.
The key to everything is evenness. Evenness of machining, evenness of heating, evenness of quench... Like Sam said, it could have been any number of things.
Read some background and you'll get some great tips on why these things come about.
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Post by Deleted on Apr 20, 2008 19:28:09 GMT
i also read that brine is good on 1095 carbon steel would u recomend that or should i go with olive oil...would conola work aswell?
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slav
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Post by slav on Apr 20, 2008 19:35:44 GMT
I'm not surprised that you craced your first blade, especially using water. Don't feel too badly, it happens a lot.
As the guys have said, try quenching in oil. I have used vegetable oil and it worked well. Sam tells me that Automatic Transmission fluid or Peanut Oil are good for quenching.
You should only have to normalize it a couple times. I use the same 1095 and get good results bringing it to an even bright red, letting it air cool over the fire, bringing it back to a dull red, and letting it cool over the fire. Keep it close to the fire when air-cooling so it cools off gradually. Also do not lay the blade on anything or else the difference in temperature will cause it to curve as it cools.
It just takes practice, and a few failed attempts are to be expected. That's why I told you to buy the long piece of barstock.
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Post by Deleted on Apr 20, 2008 19:52:29 GMT
after the quench how springy should a blade be?
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Post by dand on Apr 20, 2008 19:57:10 GMT
Well, right after the quench I wouldn't try to bend it at all.....it will probably snap........however, after you temper it back it should spring back to true.....however, the amount of flex depends on many things such as thickness of blade, the geometry etc. Hope this helps, Dan
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Post by Deleted on Apr 20, 2008 20:23:37 GMT
lots thanks!
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Post by Deleted on Apr 20, 2008 21:04:19 GMT
no cracks!!! or at least non that i could see or feel when i quenched it. i used a brine solution because im still a lil scared to use oil. but it did bend to the right a little is there any way i can correct this with out snapping the blade?
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slav
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Post by slav on Apr 20, 2008 21:11:24 GMT
Like Dan said, after the quench it will snap if flexed.
Temper it in the oven for about an hour at 400 or so. After that you should be able to prop it up with a block and stand on it with one foot and bounce without it even taking a set.
...at least that's how springy mine have been, despite them being DH.
EDIT: If it curved during the quench then there is no way to fix it without annealing it, bending it back in its softened state, and starting over. But if you've still got your fire going and all, then it shouldn't take that long.
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Post by Deleted on Apr 20, 2008 21:16:12 GMT
if i just normalize it will that be soft enough to bend it back and start over?
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slav
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Post by slav on Apr 20, 2008 21:22:47 GMT
Yeah, that's what I meant. Normalize it, bend it back, re-quench.
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Post by Deleted on Apr 20, 2008 21:46:47 GMT
tempering the knife wont do anything to my oven will it? bad smells, stains, or ruining it???
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slav
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Post by slav on Apr 20, 2008 22:00:59 GMT
Nope. I guess make sure to rinse the oil or brine off the blade before putting it in, but other than that nothing to worry about.
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Post by Deleted on Apr 20, 2008 23:14:17 GMT
yup its strait now and in the oven! thanks for ur help guys
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Post by Deleted on Apr 21, 2008 3:01:41 GMT
and now the blade is done!!!! well mostly 120 grit finish so far gunna go higher when i get a chance to run to home depot and get some higher up sand paper. my first "from scratch" knife what ya think? couldnt of done it with out ur help thanks!!!!!!
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slav
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Post by slav on Apr 21, 2008 3:24:45 GMT
Looks very nice for a first blade from scratch. I'm glad it worked out!
Hint: next time spend a lot more time with the angle-grinder so that you have a much wider bevel that's nice and even.
EDIT: Oh yeah I almost forgot; +1 Karma (well deserved). Welcome to the club!
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Post by Deleted on Apr 21, 2008 3:55:44 GMT
it wont hurt it if i go back and widen that bevel out will it?
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slav
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Post by slav on Apr 21, 2008 4:05:31 GMT
No, it won't hurt. Just make sure you don't get the blade hot while you do that, or else it will lose it's temper. An angle grinder will definitely get it too hot, so you will have to use a belt sander or hand files.
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