Acceptable finish

[jdm61]

So I am working on yet another 270 mm AEB-L suji. What I have been doing with these lately is grinding them down pretty thin and then working my way up to 65 µm gator belts. I then scrub them down with 320 grit EDM stones with occasional trips back to the 65 µm built to get rid of some of the stubborn 80 and 120 marks that I missed. Once I am done with that I go with 400 and 600 grit rhynowet paper And end up with what is essentially a pretty slick 400 grit hand rubbed finish. It obviously takes a bit less time then the thousand plus grit finish that I put on one of my W-2 knives or the 800 minimum I put on the Damascus blade before etching. But it’s still a bit of work and as I am not a big name who can ask for top dollar for anything like say the guys at Bloodroot Blades or Cut Brooklyn, I really need to think about laborsaving methods. At the same time I have seen some finishes on some of these previously mentioned expensive blades that I really don’t like all that much. Obvious belt finishes ground at an angle and such. So what do you guys think would be a minimum acceptable machine finish for lack of a better term and what else would you use to get it? I understand that the disadvantage of not doing the thing with the EDM stones is that I have to grind my edge down even thinner because I don’t get that last little kick from the stones so that I can just go straight over to 1000 grit Waterstone just at the edge. I appreciate the input

 

[timos-]

I really like the look of Devin Thomas's belt finish as well as Butch's. Not only do they look great but they work very well and are easy enough to maintain. When I first started making blades in earnest I figure id skip right over belt finishes and do a "higher quality" hand finish. Well one day I decided to do a quick belt finish and it came out like crap....no matter what i did it came out like crap. Then I realized its not so easy to do it well, but once you have the process down it is very efficient. Lately Ive been going with 40 grit ceramic to remove 90% , then 120 grit blaze to get down to the deepest of the 40 grit marks...then a gator 160, and finally a gator 65 .... then some slow (40% speed) steady passes on a medium scotchbrite and I end up with a pretty slick finish. It seems too be a little too sticky though (irregardless of grind geometry) so I am going to get a fine scotch brite and see how that goes.

 

[kuraki]

Well, like timos said, for a while I couldn't get what I thought was an acceptable belt finish. Part of it was due to my grinding ability. When I got to the point that I could make good, full length clean passes, I'd inevitably find other issues like streaking, or something undesirable, OR worse yet, a good clean surface from a 400 grit belt on the platen left a different shape surface than the "finish" belt I wanted to use, like cork, because it was stiffer or less stiff and floated over the platen just funny enough that 99% of the bevel cleaned up well with the cork belt but because they remove so little material, essentially reprofiling the entire bevel to clean up the last teeny bit at the top or bottom was impossible.

So 2 things made a belt finish possible for me. One is the rotary platen with a glass platen behind the longest length. If my last few passes with cutting belts, say 400 or 600 are done on that, there's enough cushion that my cork belts follow really well and it cleans right up. The second thing is scotch-brite, as there's enough cushion in the belt itself to conform and make the final finish uniform. I really only use the scotch-brite on full flat grinds, as it tends to bleed over into the flats, and while it may not be a true XXX grit finish, it's definitely uniform and nice looking, especially when you use some buffing compound with it.

Example: Grey superfine scotch-brite with black compound on AEB-L no less.

You can obviously see some striations in the grind, but they are "soft" like an m instead of sharp like an M if that makes sense.

But I don't really like it for the high wear steels and stick to cork for them. Scotch-brite hardly even touches M390 or M4 at hardness.

 

[Stromberg Knives]

I'm getting pretty fast at hand sanding (I guess it's all the practice). But what sped up my process the most was when I started lengthwise grinding. It really minimizes the hand sanding a lot, if you want the scratch pattern lengthwise of course. I finished a 270mm Sujihiki in RWL34 a couple of weeks ago, and was amazed how fast I could get it ready for the finishing hand sanding.

I did lengthwise belt grinding up to Trizact A45 and then minimal work with the Rhynowet 400 grit and upwards.

Unfortunately, I don't have any good pictures of the finish. It's really hard to take photos of these long blades.

 

[Matt Rochester]

I've tried a few belt finishes but cannot get past the marks at the top of the plunge up onto the flat. They drive me nuts. Even on a full flat grind I still get a few.

 

[daizee]

Following with interest...
I'm not happy with my belt finish process yet.
Typically I'll do major grinding with 60 and 120 ceramic, then hand-sand from 180-280 before heat, then 180 or 280-400 after for finish. It's the first 180 hand-sanding after the belt grinding that's miserable...

 

[Willie71]

I’m in the same boat. My belt finishes aren’t great. I like scotch brite. A leather strip on the platten helps.

 

[JTknives]

I love the finish gator belts give me. But am wanting to try out cork and scotch bright belts. This is a A64 gator finish.

 

[lanternnate]

Not a “machine finish”, but a variable speed disc grinder will let you get into higher grits while still being “machine assisted.” Then you can start your hand sanding at a higher grit, which means less time hand sanding.

 

[E.Carlson]

The only machine finish I can pull off is on plunge less kitchen knives. I hand sand to 400 or 600 and use the grey super fine scotch brite lenghwise on a wheel. Using the front and bottom of the wheel helps blend in the lenghwise hand finish already there.
Just don't scratch it once the handle is on!

 

[jdm61]

All of my kitchen knives are plungeless. I have tried the lengthwise thing a couple of times with gator Scotch-Brite and cork. I may need to try that a few more times until I get it right as I like the look of the hand rubbed type finish

 

[Nathan the Machinist]

400 grit Klingspor 312 (the yellow J-flex) belt finish, lengthwise grind.

This won't solve all your problems, but it helps iron out shmoo in your grinds and gets you a head start on your hand finish. Or, once you dial it in, it works really well on things like A2 and simpler steels with no hand sanding. ^ that's a belt finish.

You can get a belt wet and stretch it so it will run over top another belt. Running two belts gives you a little extra cushion. So does a radial platen with a platen backing it up.

 

[butcher_block]

50 120 A300 A100 A65 fine scottbrite belt loaded with black/grey buffing compound the compound. is a 2 fer as it keeps the heat down and coats the blade with waxy finish (great for a carbon blade) and it softens the scottbrite belt marks with more even finish adn faster cut (its a win all around )
ooo and to add i finish the flats after the bevels to get that crisp look back into the grind
crappy phone pic of tight finish

 

[Jesse Latham]

I work through A100, A65, A45, A16 then go to a 400g cork. Works for me.

 

[LARRYZ10]

May I give my opinion? I am 68 years old and for about ten years now I have been doing a high polish finish of knives. I pretty much stopped about 2 1/2 years ago when I saw many professional knife makers doing a satin or brushed finish and read about how their customers wanted that look. I like a nice satin finish as well so I began experimenting on the best way to achieve a professional looking job. In my opinion to get a nice finish you should grind your bevels to 400 grit before heat treat if you are grinding stainless steel like CPM 154. then after heat treat start with a fresh 400 grit J-flex type belt and renew your finish after grinding your bevels to an edge geometry that gives a good sharpen able edge . Use a 400 grit cork belt for a few passes and then switch to a fine or a super fine Scotchbrite or similar belt. Inspect closely and see if you like the finish. If not take it back to 400 grit and if you have one a 500 grit belt to get a nice scratch pattern. If you are still unhappy then put your blade in a horizontal wood vise and hand sand the bevels longitudally until they are smooth and go back to either the 400 grit or the scotchbrite or both. I still make my hunting knives with a deep hollow grind and a high polish finish which my "older" customers love . I Like the way water just beads up on a high polish knife blade. Once again these are just my opinions. Larry

 

[JG Custom Metal Works]

May I give my opinion? I am 68 years old and for about ten years now I have been doing a high polish finish of knives. I pretty much stopped about 2 1/2 years ago when I saw many professional knife makers doing a satin or brushed finish and read about how their customers wanted that look. I like a nice satin finish as well so I began experimenting on the best way to achieve a professional looking job. In my opinion to get a nice finish you should grind your bevels to 400 grit before heat treat if you are grinding stainless steel like CPM 154. then after heat treat start with a fresh 400 grit J-flex type belt and renew your finish after grinding your bevels to an edge geometry that gives a good sharpen able edge . Use a 400 grit cork belt for a few passes and then switch to a fine or a super fine Scotchbrite or similar belt. Inspect closely and see if you like the finish. If not take it back to 400 grit and if you have one a 500 grit belt to get a nice scratch pattern. If you are still unhappy then put your blade in a horizontal wood vise and hand sand the bevels longitudally until they are smooth and go back to either the 400 grit or the scotchbrite or both. I still make my hunting knives with a deep hollow grind and a high polish finish which my "older" customers love . I Like the way water just beads up on a high polish knife blade. Once again these are just my opinions. Larry

I always kind of wondered how people were able to grind up to 400 grit prior to heat treat and then just finish with that belt(or higher than 400 grit) after heat treat. Are you grinding your bevels to near completion before heat treat? How thick are you grinding your edges prior to heat treat? I usually leave my edges at around .040” thick before heat treat. That’s a good amount of meat to grind off with a 400 grit belt. It’s also a lot of meat to start an edge from. I like to grind my bevels on the thin side(post HT) before putting an edge on them. I’ll take my chef knives down to near zero before putting an edge on them. Do you just leave yours thicker?

 

[HSC ///]

a few things for you to try out that take just minutes to do.

1) scotchbrite belt red
2) flap wheels, 240 and then 320 and then a green compound buff for a polish
3) brownells polish-o-ray on a buffing wheel, it's like liquid sandpaper at 320-400 grit.
4) Already mentioned above - cushioned platen.

 

[LARRYZ10]

I always kind of wondered how people were able to grind up to 400 grit prior to heat treat and then just finish with that belt(or higher than 400 grit) after heat treat. Are you grinding your bevels to near completion before heat treat? How thick are you grinding your edges prior to heat treat? I usually leave my edges at around .040” thick before heat treat. That’s a good amount of meat to grind off with a 400 grit belt. It’s also a lot of meat to start an edge from. I like to grind my bevels on the thin side(post HT) before putting an edge on them. I’ll take my chef knives down to near zero before putting an edge on them. Do you just leave yours thicker?

I always scribe my edges with a 04

I always kind of wondered how people were able to grind up to 400 grit prior to heat treat and then just finish with that belt(or higher than 400 grit) after heat treat. Are you grinding your bevels to near completion before heat treat? How thick are you grinding your edges prior to heat treat? I usually leave my edges at around .040” thick before heat treat. That’s a good amount of meat to grind off with a 400 grit belt. It’s also a lot of meat to start an edge from. I like to grind my bevels on the thin side(post HT) before putting an edge on them. I’ll take my chef knives down to near zero before putting an edge on them. Do you just leave yours thicker?

I always scribe to .040 but I almost end up at .020 or a tiny bit less before heat treat. I use the marks to keep me centered. Yes, I when using stainless steel I try to finish my blade very close to what it will be. This is because in many cases I have fitted and drilled my guard which I want as tight as possible before heat treat because I know that I will smooth it on the flat platen and I don't want the guard to have any space. To me a tightly fitted guard is a show of professionalism on a finished knife. I think on kitchen knives you should leave yourself enough meat to grind a nice usable edge because you don't have deal with a guard in most cases. You will know what works for you by your finished blade. Larry

 

[Justin Schmidt]

220 grit AO jflex

600 grit hand sand

Best thing that helped me was the disc grinder. I come off the grinder at 120, go to the disc at 320, then hand sand 320 and 600.
Using the disc grinder takes all the vertical scratch Mark's out and theres np problem with a stray 60 or 120 grit scratch(s)

 

[argel55]

I grind to 400 grit then black rouge on a sisal wheel then finish on extra fine scotchbrite belt.