View Full Version : More questions about prepping cork belts


Jamey Saunders
02-18-2004, 01:45 PM
I received my first cork belts today (from Pop's -- great guy to do business with. Even recognized me as a prior customer!)

I have to admit that the belts I received were not exactly what I was expecting. The 600 and 800 grit belts look more aggressive than the 36 grit belts I have at the house.

My question is this -- I've been reading the threads about prepping cork belts. I'm supposed to push the edge of a piece of steel into the surface for ten minutes. Is this to remove *all* the grit, or just the high spots? Looks to me like doing that would remove all the coating. I was under the impression that I'm just supposed to knock down the high spots on the belt, but unless they're a helluva lot tougher than they look, I'm going to strip the belt clean in ten minutes.

So what am I after? Just knocking down the high spots, or stripping the belt entirely?

Messinger
02-18-2004, 01:51 PM
Perfect timing! I am wondering EXACTLY the same thing. (planning to hit the grinder tonight)

-Ben

ps - I've read ALL the threads on this.

Jamey Saunders
02-18-2004, 03:29 PM
Yeah, I've read all the threads, too. I guess what's throwing me is that the cork belts look *nothing* like what I was expecting. I guess I was expecting a belt that was 1/16 to 1/8 of an inch thick, being coated with the kind of cork you find on a bulletin board. Don't know why, but that's the picture I had in mind of a cork belt.:rolleyes:

wildbill254
02-18-2004, 03:38 PM
I have the same question..

Also are we supposed to use the "edge" lying flat on say a tool rest or are we to use the side of a piece of steel like we are hollow grinding a blade?

Thanks

Bill

Steve
02-18-2004, 03:42 PM
They normally look like 36 grit or so. They are pretty thick. One I have here is .050" and another is .065" thick.

Get them running fairly fast, apply some green chrome compound and push that edge of the steel into it, using a work rest if you have one. I guess you could strip the coating off but I doubt it. Be gentle on the edges. They need to be worn slightly around teh edge of teh wheel, but carefully, this can strip the coating. I'll try to post a photo, soon, of a broken-in belt.

Just smooth them out some, it really does take ten min. Take it slow, and get back to us, here, oK?

Thaks and have fun, wear a mask, glasses.

Jamey Saunders
02-18-2004, 04:01 PM
Thanks, Steve. I can see now that by using the compound while breaking in the belt, I'm not as likely to completely strip the belt. I'll give it a go and see how it works tonight.

Thanks again!

Darren Ellis
02-18-2004, 04:22 PM
You know, I've wondered the exact same thing, even after having read the various posts. Given the excellent results claimed by the people who use this technique, and the obvious confusion of the written word in describing this process, it seems that this would be a great topic for a visual tutorial! hint, hint... :)

-Darren

SteveS
02-18-2004, 04:28 PM
Steve - Please post a picture! I'm wondering the same thing.

Do you use a round piece of metal or a sharp edge?

I've had some success with this and ATS-34. But some metal dust or old grit from the bench or something got on the belt. Now it leaves marks. I tried stripping the compound and starting over, but it's still there.

So guys, once you have your belt working go out of your way to keep it clean.

I've bought a new belt and am starting over. Hope I get it right.

Steve

george tichbour
02-18-2004, 05:02 PM
These belts are just hitting their prime when there is little or no texture showing and they work well until the weave of the cloth shows through.

The intent of breaking in the belt is to flatten the tops of the grains of cork leaving a little of the black silicon carbide grit surrounding a button of cork. This allows the cork button to carry the compound and the little bit of silicon carbide left on the belt removes scratches. They can be broken in dry and this way you see the cork grains opening up more easily but use green compound before you begin using the belt.

They are not susceptable to cross contamination so odds are if there are scratches showing after you have used the belt they were there before you started and now you can see them.

Bill Vining
02-18-2004, 05:14 PM
I have read through several of the "cork belt" posts and tried it myself. I took a new 400 grit cork belt put it on my KMG with he platen and a tool rest. I then used a 1 1/2 x 12 wide piece if stainless and started wearing off the grit. One warning............wear a respirator and if you have dust collection, turn it on. It makes one hell of a mess.

I actually leaned on it pretty hard to the point where I thought I would tear the belt. No such luck, this thing just kept on going. Afetr about 10 minutes (in spurts if 2 minutes) the belt was fairly worn down and smooth. I applied some Green Rouge and tested it out. As we say in the software business, "Works as Designed". I was very happy with the results.



Thanks................
Bill

SteveS
02-18-2004, 06:05 PM
Originally posted by george tichbour

They are not susceptable to cross contamination so odds are if there are scratches showing after you have used the belt they were there before you started and now you can see them.


George,

Hmmmmm.... Last time I used them it was after I hand sanded lengthwise. So I know all the marks came from the belt.

Now I'm puzzled.

Steve

Steve
02-19-2004, 01:10 AM
Bill (Cigar Man) tells it the way it is.

Just use a flat piece of steel, I don't care what kind it is. Turn on the machine and push the edge steel into the belt, it makes a lot of dust, but eventually, like after 10 min. the belt will start to have some smoothe, shiny flat spots, when this happens, you're about there. Use compound on the belt for a little less dirt. I think I've mentioned more than once in the above posts that it's very dirty and to wear a mask, etc.

Here's the turorial:

1. Put belt on grinder that has a tool/work rest.
2. Turn it on - fairly fast speed.
3. Take a piece of 1-2" wide x 1/8 or 3/16" or 1/4", or whatever thickness
steel and push it against the belt. After the first min. or so, you can push
kinda hard, like Bill says above.
4. Do it for 10 min. (Put green chrome compound on belt at any stage.
Use it, green chrome, when polishing blade once belt is "broken in.")

I'm not trying to be a smart aleck, that's really just all you do.

You might try, perhaps, the piece of steel against the belt again, to clean off that scratchy thing. I've had that happen, drives you nuts! Can't tell you what the cause of the problem is, really.

Two entries following this one, in this discussion, you'll find a photo of a "broken-in" belt alongside a new one. Hope this helps.

By the way, I never cover any of my belts or buffing wheels. Just wipe them off with a glove as they are starting to run when you put them on the grinder. Rake the buffing wheels if you feel it necessary, though I seldom feel the need. That's just what I do, you do what works for you. You're the boss in your shop. Keep an open mind. Experiment. Then please tell us of any better ways that you may come up with.

Jamey Saunders
02-19-2004, 08:38 AM
Well, I did it. I prepped the belt, loaded it with buffing compound, and polished a blade. Worked really well. Those belts really are tougher than they look! Thanks again for being patient. I was just thrown by what I received not being what I was expecting!

Thanks again for the great advice, Steve.

Steve
02-19-2004, 10:37 AM
Great! Glad it worked. You'll get to know that/those belt(s) well. They last for years, literally. For me, life is better with them.

Have fun!

http://www.srjknives.com/pics/belt.jpg
Left belt is a well broken-in 400 X cork belt that is about a year old. Right side is a brand new 400x Cork belt. Note the large, smooth, shiny surface area that has been smoothed out, leaving some valleys/low spots here and there. Yours, Jamey, will probably not have this much "smooth area" yet, most likely, just the tops knocked off the high points, so to speak. That's fine, so long as it works.

Thanks, Alex, for postng the photo!

Darren Ellis
02-19-2004, 04:24 PM
Thanks Steve, as they say, a picture can be worth a thousand words! :)

-Darren

Steve
02-19-2004, 06:23 PM
Thanks for your patience Darren. I hope it helps. Like I say, don't try to get that much smoothness at the start, just wear some of the roughness off, so the belt is cutting smoothly and cleanly, no ripples in the blade, etc. 10 full min. pretty much odes the trick, pushing fairly hard.

Messinger
02-19-2004, 07:42 PM
The posts in this particular cork-belt thread have answered quite a few questions I had after reading the other threads. Now I think I might have messed up. After reading the older threads I thought "Well why pay for the grit if you're just going to strip it off when breaking in the belt" so I ordered my cork belts plain (no abrasive). You think they're still going to work as described if I follow the same break-in and load them with green-chrome? Anybody using them this way?

-Ben

Steve
02-20-2004, 01:29 AM
Didn't work for me. The green chrome is working more as a lubricant than an abrasive. The silicon carbide embedded in the cork is what cuts, the compound just keeps it smoother and helps it run cooler, I believe. Not that I've scientifically studied any of this, just my thoughts.

Steve
02-26-2004, 09:50 PM
OK Jamey and Darren, how goes the polishing?? hope everything is working out OK.

Thanks, whenever you can drop a line.

Jamey Saunders
02-27-2004, 08:37 AM
It worked pretty well. I'm still getting some scratches from the grit on the belt, but I expect that to go away as the belt starts to hold some more buffing compound. I manly wanted to use the polishing belts to bring the blades to the point where the hand-rubbing involved would be at a minimum...;)

Frankly, it's been to cold, rainy, and just plain nasty down here the last week to get outside and do any knifemaking...:(

Darren Ellis
02-27-2004, 09:03 AM
Originally posted by Steve
OK Jamey and Darren, how goes the polishing?? hope everything is working out OK.

Thanks, whenever you can drop a line.


Hi Steve,

I like it! I'm glad you turned me on to this, so far I like the results! :)


Originally posted by Jamey Saunders
Frankly, it's been to cold, rainy, and just plain nasty down here the last week to get outside and do any knifemaking...

outside!?, ohh, yuck! :( Best thing I did for my shop was to put a heating/air conditioner unit in there, 19,500 BTUs, keeps me cool in the Summer and warm in the Winter! :D :D

:)

-Darren

Steve
02-27-2004, 09:33 AM
Thanks for the report.

Don't be afraid to wear on it a little more with the edge of the steel bar. That might smooth things out a bit, maybe for another 30 seconds to a minute longer. If that doesn't get rid of the scratches, do it a little more.

Cold huh? It's warm here, almost up to freezing for a change. All month it was about 15-20? every morning at this time, 0800-0830.

My shop has 6" fiberglas in the walls, 1" of foam and a heater and also an air cond. in one wall. The temp is good most of spring early summer and fall. Need heat in winter and air for about a month in hottest part of summer. I'm spoiled. My first shop, in the milk shed, was never warm when it was cold and never cool when it was hot!

Keep working with them, you'll work out the kinks. Thanks again.

Jamey Saunders
02-27-2004, 09:42 AM
Originally posted by Darren Ellis
outside!?, ohh, yuck! :( Best thing I did for my shop was to put a heating/air conditioner unit in there, 19,500 BTUs, keeps me cool in the Summer and warm in the Winter! :D :D

I have a shop. Unfortunately, my brother has been in control of it for the last three years restoring his 69-70-71-82 Chevelle SS. Wish he'd hurry up and finish it so I could have my shop back. I don't think he'd appreciate grinding dust on his Viper Red paint job!:eek: :eek:

Originally posted by Steve Cold huh? It's warm here, almost up to freezing for a change. All month it was about 15-20? every morning at this time, 0800-0830.

Anything below 50* is cold here in the Deep South...;)

Frank Niro
02-29-2004, 11:40 PM
I found that without the green chrome polish the pores in the belt will load and then the belt will end up doing little or no cutting. About a dozen yeas ago when I was using these for a lot of ,major cutting I was told to use belt grease on them. When I asked why, they didn't have an answer but I found that without the grease they appear to have a very short life because of the pluging up problem,which of course is the opposite. I also found that they cut better on hardened steel better than on the soft stuff. Just a note that may be an answer for someone. Oh buy the way you can still get the grease to use but man, what a mess it makes when you put it on. It was a big day for me in my shop when I found the polish worked. Frank

Jerry Shorter
03-01-2004, 09:45 AM
Steve, If the green chrome is acting as a lubricant, Then maybe some belt wax/grease would work in the same way, or have you tried that?
Jerry

george tichbour
03-02-2004, 07:14 AM
I will use the same belt for months before they wear too smooth to cut. The grit on the belt is necessary to remove scratches and leave a smooth surface. The cork grains are to hold the compound.

I have experimented with Scotchbrite Type T Low stretch belts which are a white polyester felt belt with no grit at all but they give an irregular surface, much like the surface that has been buffed to death.

Jerry Shorter
03-02-2004, 12:57 PM
Steve, We are proably thinking of the same thing, I think that I just called it wax because that is what it looks like. Sorry for the confusion.
Jerry

Steve
03-02-2004, 03:13 PM
Originally posted by Jerry Shorter
Steve, If the green chrome is acting as a lubricant, Then maybe some belt wax/grease would work in the same way, or have you tried that?
Jerry

The wax lubricates, for sure, but seems to be not as slick as the compound, a bit more messy, too, perhaps. Whatever works best for you is the way to go, after giving other ideas a shot. (I modified your quote to include "grease" and then deleted my question, since we're probably talking about the same thing here. Hope that's OK).