Steve Johnson cork belt technique

jdm61

jdm61

itinerant metal pounder
Joined
Aug 12, 2005
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So do any of you use this technique for finishing blades? I have been playing around with it a little bit the last couple of weeks and it seems to work fairly well even for somebody like me who has never done highly polished blades other than say a 1000 grit hand rubbed finish. It even works for CruForge V which as many of you know, it a PITA to finish. I have used a very worn 400 grit cork belt with gray compound and a worn 1000 grit cork belt with the green chrome and both do cool things. I have read that the technique works especially well on hollow grain with wheels. I have been using my 72 inch Nathan platen on a couple of blades and the combo of 120 Blaze after the rough grind, a couple 0f flavors of Gator starting with 160 and typically ending with 30 micron and the cork just lock right in. I will be interested to see how much closer to a mirror finish I can get by going finer on the Gator belts, like to 15 or even 5 if they make them.

The other interesting thing that I did this past week was to finish a damascus chef knife using almost all grinder belts. Because it was plungeless grind, I was able to do the "cross sanding" and make sure the previous grit scratches were gone. That is not easy on a big blade at high hardness if you are dong it by hand. The next to last grind that I did was lengthwise with the 30 micron Gator then the same way 400 cork belt with the gray compound. I then gave it a quick set of like 20 straight hand sanding pulls per side with 1500 grit Rhynowet just to "open up the pores" and etched. i used the same 1500 on a micarta block to clean off the tops and it turned out great. I have been a big fan of the Gators for a while, but now I need to get a few more cork belts.
 
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Steve Johnson pioneered the use of cork belts in knife making. I have been using them for years dry and with compound.

If you want a mirror finish then get a "Cork" belt with no grit. Prepare it like the others and then apply green chrome compound.

That will get you a mirror finish or close enough to where a couple of minutes on a buffer to get it to mirror.
 
Im interested in this. Where do you find this technique? I just bought a full set of cork belts. So far the best thing I have come across is the 3M microfilm belts from pops with a leather backer. I can go from 220 to 2000 in 15 to 20 minutes. The nice thing about them is using them wet. Once you get to 400 it's hard to use any pressure with a dry belt. I'm hoping that the cork is more precise than scotchbrite. I have to admit that I'm not sure that I'm using them right.
 
Noted. Title changed. Not sure where I came up with John Young. Isn't he an astronaut? LOL Where do you get the no-grit cork belts?
AVigil said:
Steve Johnson pioneered the use of cork belts in knife making. I have been using them for years dry and with compound.

If you want a mirror finish then get a "Cork" belt with no grit. Prepare it like the others and then apply green chrome compound.

That will get you a mirror finish or close enough to where a couple of minutes on a buffer to get it to mirror.
Click to expand...
 
Tru Grit has the plain cork belts
 
I do not use bar stock for breaking in. I use round stock to break in. I find it will smash the cork down and not strip it off.

You do have to do the break in 10 minium by the clock. Push firmly and watch the clock

"To break in the cork belts, put them on the grinder with a tool rest in place. Using a scrap piece of blade steel, or whatever, wear on that belt for a good 10 minutes. Be careful not to "break" the corners, or edges, of the belt too aggressively, or all the cork and polishing media will peel off. Buffing compound helps here, I think, in making it easier to "fold" around the edge of the wheel a little. You do need to slightly break or round the corners of the belt around the edge of the wheel, however, but be careful not to overdo it. It is smelly and dirty for that 10 min, but it takes that long (10 min. by the clock) to break the belt in.

A new cork belt looks like a 36 grit belt, it's so rough. When it's broken in, it has some smooth spots, some valleys and starts taking on a smoother, slightly shiny appearance. Use the buffing compound during the "break-in." Be advised tht it takes some pressure, and time to do the job. You don't want to peel off cork, you are trying to just smooth out the surface of the belt somewhat.

These belts will then last you 2-3 years, assuming that you do 50-100 knives per year. Take a little care with the edges, as I've noted above. Use ample compound. Hopefully, you might be as happy with this process as I am. The cork belt is the best thing to come along in many a year, as far as I'm concerned.
-Written by S.R. Johnson-Knifemaker"
 
AVigil said:
I do not use bar stock for breaking in. I use round stock to break in. I find it will smash the cork down and not strip it off.

You do have to do the break in 10 minium by the clock. Push firmly and watch the clock

"To break in the cork belts, put them on the grinder with a tool rest in place. Using a scrap piece of blade steel, or whatever, wear on that belt for a good 10 minutes. Be careful not to "break" the corners, or edges, of the belt too aggressively, or all the cork and polishing media will peel off. Buffing compound helps here, I think, in making it easier to "fold" around the edge of the wheel a little. You do need to slightly break or round the corners of the belt around the edge of the wheel, however, but be careful not to overdo it. It is smelly and dirty for that 10 min, but it takes that long (10 min. by the clock) to break the belt in.

A new cork belt looks like a 36 grit belt, it's so rough. When it's broken in, it has some smooth spots, some valleys and starts taking on a smoother, slightly shiny appearance. Use the buffing compound during the "break-in." Be advised tht it takes some pressure, and time to do the job. You don't want to peel off cork, you are trying to just smooth out the surface of the belt somewhat.

These belts will then last you 2-3 years, assuming that you do 50-100 knives per year. Take a little care with the edges, as I've noted above. Use ample compound. Hopefully, you might be as happy with this process as I am. The cork belt is the best thing to come along in many a year, as far as I'm concerned.
-Written by S.R. Johnson-Knifemaker"
Click to expand...
Thanks for that. I would have given the edges a bit to round over and called it good. They look like they are going to be great a polishing. Will they remove much metal? Compared to a gator belt how much heat do the generate? Also would wax work as well for this as compound?
 
They do generate heat, but nowhere near as much as a Gator.
Storm W said:
Thanks for that. I would have given the edges a bit to round over and called it good. They look like they are going to be great a polishing. Will they remove much metal? Compared to a gator belt how much heat do the generate? Also would wax work as well for this as compound?
Click to expand...
 
Dry they leave a finish very similar to a gator.

With green compound they will remove scratches and more material but slower then other belts.

Take your grind to 400 gator then switch to cork 400 green compound to refine and find tune the grind, plunges and move up with other 800, 1000 cork with compound to polish
 
jdm61 said:
Noted. Title changed. Not sure where I came up with John Young. Isn't he an astronaut? LOL Where do you get the no-grit cork belts?
Click to expand...

John Young is a knife maker that lives near and learned from Steve Johnson. He’s a very good knife maker.

Hoss
 
Ah. Hence the confusion. Thanks for the info, sir. The other John Young was also an astronaut. He was the only guy top walk on the moon and fly the shuttle. :D
DevinT said:
John Young is a knife maker that lives near and learned from Steve Johnson. He’s a very good knife maker.

Hoss
Click to expand...
 
Adam, do you just use green chrome compound for all of the grits in your cork belts?

I only have used one cork belt so far and I think it's a 400 grit cork that I apply some either 220 or 400 grit compound to (I have to recheck, it's been awhile). I'm pretty sure I got the idea from Nick W for using a lower grit "polish-o-ray" compound for a nice lower grit & user-friendly satin finish and wanted something other than gator belts, and it works nicely although my compound is a different brand, but I've been meaning to experiment a bit more with them for a higher polish.

~Paul
My Youtube Channel
... (Just some older videos of some knives I've made in the past)
 
I use the technique of Master S.R. Jhonson for several years and I can assure you that it works well. Over time I have seen that it works on CPM154, RWL34 and other similar steels. The concept of mirror finish is very special, we carry out a long series of increasingly thinner scratches until we no longer see them .... this is to say that I do not see them and I am satisfied with the mirror polish effect achieved but with another eye, different brightness may not be satisfied. A advice I can give is to look at the surface of the knife with different inclinations and with different types of lighting, when you are satisfied with the result, stop!
 
TRIVIA. Steve Johnson worked with Bob Loveless back in the early 70s in that little one car garage in Lawndale Ca. and made some nice knives back then. WB
 
Wild Bill 1 said:
TRIVIA. Steve Johnson worked with Bob Loveless back in the early 70s in that little one car garage in Lawndale Ca. and made some nice knives back then. WB
Click to expand...

Trivia question: what steel did they make knives out of when Steve first worked for Bob?

Hoss
 
I dont know the answer to the trivia... but I feel like cork belts are a hidden gem in the knifemaking world. Not enough makers are taking advantage of them.
 
does anyone have a video link on this technique? i'm interested now =)
 
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