more or less pre heat treat?

ChristoDart

ChristoDart

Joined
Jun 29, 2011
Messages
750
Heyo. First thread in this area, first and foremost I'd like to thank everyone for sharing their wealth of knowledge and information with no qualms. The archives and watching current threads have taught me more than I can express. Thank you. Let me lay a base work here. I have been lurking for more than a hot minute and done some projects here and there, but (yes another one) recently allowed my long lasting addiction to grow into making my own knives. I have learned a lot through the process, from trying to work on multiples at once to trying to finish one knife at a time. I feel I've gotten a decent rhythm now and am almost at the 20 knife mark to send out for heat treat. Question time. I understand that the more you get done pre heat treat (sanding) the less you do when you get the knives back.. harder to erase the deeper scratches etc... check:thumbup:. I've got more than a couple (12) knives I've meticulously wet sanded down to 320 thinking this was the only way. Well, I recently ordered a wider grit range/higher quality of belts and have experienced how much easier and nicer it is to bring the finish of the knife to a satin with a grinder and quality belts...Not to mention how much easier it is to grind the blank itself. Now that I have improved belts (and skill :rolleyes:)would you say to grind the knives down to a rough, low grit finish, send out for heat treat, then finish my knives to a high grit finish? I had a realization today that it would be much easier to get them close to done at a low grit as far as bevels and whatnot gos, send them out to get treated, get them back and set up for final grind and finish. I realize most of this will be answered through experience when I send these knives out but I'd like to get a collective of more experienced minds before I continue. Now I do realize I will need to hand finish to get the hand finish look at the end. I Just am beginning to "think" it may be smarter to do the last of my grinding. Thank Yall! Here are a couple photos of a couple my knives off the grinder to make the thread more interesting.





 
It depends a lot on your HT procedures. If you're heating simple steels in an open forge, you're going to have some scale to grind off after quenching. So there's not much point bringing the blades to a high finish beforehand. If you're heating properly-wrapped blades in a kiln, or unwrapped blades in an oven that has the oxygen purged out of it (like they do at Peters' HT for instance), they're going to come out very clean; so you have more options.

Steel type is an important factor, too. Simpler steels like 1084, O1, 1095, 52100 etc are not that all that difficult to hand-sand after HT and tempering. Stuff with more alloy and carbides in it (CPM-154, 3V, S35VN, etc) is naturally a lot more difficult to hand-sand after HT.

I usually hand-sand my blades with a lengthwise scratch pattern like your first pic. Since Peters does my HT and they come back nice and straight with just a bit of tempering color on them, I have the luxury of taking them to final dimensions and finish before sending them out. They just need a quick clean-up with the last grit when I get them back.

If you prefer the cross-ways belt finish (or ScotchBrite/tumbled/stonewash/blasted/various coatings etc), it's entirely up to you. Lots of handmade makers (and pretty much all larger manufactures) simply remove the mill scale or "bark", profile and drill their blades, HT them, and grind the bevels and finish afterwards. The advantages of that approach are not working on the blade twice, it nearly eliminates possible problems with warping along thin areas (tip and edge) and it's easier to keep grind lines crisp.
 
Can't really add much more to what James said already, but just to emphasize his point: It really depends. ;)

I typically do most of my grinding after HT, so it really doesn't made much sense for me to take a knife to, say, a 400 grit finish when I'm gonna be hogging off a fair amount of steel with an 80 grit belt anyhow. That being said, I typicaly work with 1095 and start out with some thinner stock anyhow, so I like to leave room to remove scale and decarb if necessary.

If I was working with something like D2, I'd probalby get the knife as close as I could before heat treat andjust give it a quick polish post HT.
 
That answers my question. Thank ya'll very much. Sounds like ill bring them to 400 pre HT. They're mostly 3v and will be going to Peter's.
 
If that's the finish you want, that's the easiest way to go :thumbup:
 
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