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The Newbies Arena Are you new to knife making? Here is all the help you will need. |
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#1
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Finish prior to heat treat and after process
Doing my second knife, graduated to 1084 from lawnmower blades. Finished knife to 400 grit satin and then heat treated. Brought to non magnetic and two trips to the oven at 450 for an hour each. Was excited to remove the tarnish and get my blade looking good again. Start to take off scale with 400 grit couldn't move it. Moved to 220 grit barely moved it. Moved to 150 grit and one and half hours later back to 150 grit satin. Holy guacamole there must be an easier way. Any suggestions?
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#2
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Well, I just do all my grinding after the heat treat is finished and that saves me a lot of trouble. But, you didn't say you have a grinder so I'm guessing you may be doing this by hand.
No point in finishing to 400 grit before HT as you've already discovered. There are some anti-scaling compounds you could put on your blade to prevent some of the scale. Finishing to 220 is about as far as I'd go before HT. After that, using fresh belts or fresh sandpaper or whatever it is you're using and backing up one grit to, say, 120 grit is where you would start your finish work. If you are doing this by hand then, yes, it is difficult but it can be done. That's where you are until you're ready to buy a good grinder ... |
#3
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You could try pickling the blade in white vinegar overnight to eat the scale and then scrub with a wire brush before returning to sanding.
Doug __________________ If you're not making mistakes then you're not trying hard enough |
#4
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Thanks. 220 makes sense. Then grind off at 120 (I have a ####ty little 1x30 Thanks again.
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#5
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Quote:
Note: Don't plunk the blade into the container, set in gently or you'll knock the bottom out of the jar (don't ask how I know this). I have a disc of rubber matting in the bottom of my jar just encase one slips. Also, if you have longer blades, those tall spaghetti jars work really well and have a screw on cap for when you are not using. ?? - you didn't mention a hardening quench after reaching critical temp, before tempering. Hope that's just a typo. __________________ Carl Rechsteiner, Bladesmith Georgia Custom Knifemakers Guild, Charter Member Knifemakers Guild, voting member Registered Master Artist - GA Council for the Arts C Rex Custom Knives Blade Show Table 6-H |
#6
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I brought it to non magnetic in a charcoal make shift forge and quenched in vegetable oil Also the information on tempering 1084 is all over the place. It seems many temper at 350 to 400 degrees. The one official looking chart showed you have to do 500 degrees to get to 59 rc
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#7
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Tempering a carbon steel at 500F or just above can create embrittlement, or so I've read. You use different tempers to achieve different results which is why various sources may quote different temperatures but 500 is too much. Try about 400 - 425 ...
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#8
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Agree with Ray. Best thing to do - make it a learning experience. Draw temper at 350 then test the edge (will most likely be too hard if you got the quench right), re-temper at 375 and re-test, then again 25 deg higher until you get the performance you want. Worrying about actual RC hardness is a waste of time until you start getting the results you want .... then it's just a number for techno's to banter about.
Bottom line is if a knife performs as designed then it is right, otherwise just a crummy poorly designed screwdriver. Note: Tempering temps is also subject to what you use to do the tempering and how you go about it. __________________ Carl Rechsteiner, Bladesmith Georgia Custom Knifemakers Guild, Charter Member Knifemakers Guild, voting member Registered Master Artist - GA Council for the Arts C Rex Custom Knives Blade Show Table 6-H |
Tags |
1084, art, back, belts, blade, blades, buy, carbon, degrees, finish, forge, grind, grinder, grinding, hand, heat, heat treat, knife, make, plastic, quenched, sanding, scale, steel, white |
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