Cork belts?

H

Happychicken

Joined
Nov 14, 2018
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176
Hi all I just purchase cork belts with abrasive in them from 400-1200 grit. Do you break them in the same way as the cork belts that have no abrasive? I was also told to add green compound to all the belts is that a good idea? Thanks
 
Yes they need a full break-in . Take a piece of 1/4" steel bar and press it against the belt moderately hard. Grind the steel for 10 straight minutes. Set a timer, because it will seem like 30 minutes. When done the belt will last for hundreds of blades. You can use a greaseless compound of matching grit on the belt to "freshen" it up every now and then. Cork belts are a lot of work, and have a learning curve, but they will polish like there is no tomorrow. You want a good 400 grit finish before moving to a cork belt.
 
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A quick word of caution: Even though there are no sparks and seemingly hardly anything is going on while you break them in for a very boring ten minutes, the steel will still get very hot. Don't ask me how I know this.
 
Ok thanks everyone I thought the ten minute thing was for the pure cork belt (the belt with no abrasive). Thanks for clearing that up! Where exactly do these fit into the progression? I see above 400 grit. Can I go to cork belts after surface conditioning belts? Thank you!!
 
Happychicken said:
Where exactly do these fit into the progression? I see above 400 grit. Can I go to cork belts after surface conditioning belts? Thank you!!
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I have had success with Trizact A30, then cork. It took me a long time to get a uniform finish with cork belts. That's not the cork belts' fault, but my fault for not getting an even enough grind before going to the cork belt. When I first started, it would take me a long time to hand sand a kitchen knife at low grit to get the waviness out. I tried cork belts to reduce hand sanding time but that obviously did not help. As my grinds became more uniform, maybe seven or eight blades into this adventure, I was finally able to get a uniform finish with cork straight off the grinder. At the same time, it did not take much time anymore to hand sand a blade because I could go to 220 or 400 grit straight off the grinder. I spent some time trying to convince myself that a vertical scratch pattern is an acceptable finish on a kitchen knife, but was not entirely successful at that. I think it's not so bad on carbon steel knives as the patina hides the vertical scratch pattern. Recently, I spent a lot of time trying to get a uniform finish with cork belts in the lengthwise direction without success while the Scotchbrite belts works well for this. The Scotchbrite belts seem to have a lot of give and conform to the blade, the cork belts not so much. I like the cork belt finish better, though. It is hard to describe the difference, the Scotchbrite has a texture with longer scratches. They both give a nice satin texture, maybe you could call the cork belt finish "creamier".

Ok, that was a long back story to answer your question "where exactly do cork belts fit into the progression". For me, the answer is unfortunately nowhere. I cannot get a uniform lengthwise texture with them and while I like the surface finish they give me, I cannot bring myself to like a vertical scratch pattern. The progression I am currently using is P60/P120 ceramic, then Trizact A100/A65/A30 on glass and/or felt lined platen. I then use a medium and a super fine Scotchbrite belt in the lengthwise direction with a contact wheel. This gives a pretty nice satin finish, is quick to do and does not involve any hand sanding at all.
 
Hubert S. said:
I have had success with Trizact A30, then cork. It took me a long time to get a uniform finish with cork belts. That's not the cork belts' fault, but my fault for not getting an even enough grind before going to the cork belt. When I first started, it would take me a long time to hand sand a kitchen knife at low grit to get the waviness out. I tried cork belts to reduce hand sanding time but that obviously did not help. As my grinds became more uniform, maybe seven or eight blades into this adventure, I was finally able to get a uniform finish with cork straight off the grinder. At the same time, it did not take much time anymore to hand sand a blade because I could go to 220 or 400 grit straight off the grinder. I spent some time trying to convince myself that a vertical scratch pattern is an acceptable finish on a kitchen knife, but was not entirely successful at that. I think it's not so bad on carbon steel knives as the patina hides the vertical scratch pattern. Recently, I spent a lot of time trying to get a uniform finish with cork belts in the lengthwise direction without success while the Scotchbrite belts works well for this. The Scotchbrite belts seem to have a lot of give and conform to the blade, the cork belts not so much. I like the cork belt finish better, though. It is hard to describe the difference, the Scotchbrite has a texture with longer scratches. They both give a nice satin texture, maybe you could call the cork belt finish "creamier".

Ok, that was a long back story to answer your question "where exactly do cork belts fit into the progression". For me, the answer is unfortunately nowhere. I cannot get a uniform lengthwise texture with them and while I like the surface finish they give me, I cannot bring myself to like a vertical scratch pattern. The progression I am currently using is P60/P120 ceramic, then Trizact A100/A65/A30 on glass and/or felt lined platen. I then use a medium and a super fine Scotchbrite belt in the lengthwise direction with a contact wheel. This gives a pretty nice satin finish, is quick to do and does not involve any hand sanding at all.
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I really need to find a supply of this felt here, or a replacment.

I've tried a couple of things for the platen and neither has worked satisfactorily.
 
Mcmaster carr has the hard felt. I am trying to get an extra platen assembly so I have glass on one, hard felt on the other and a plain metal one.
 
Thanks again!
Hubert I am using a very similar progression now only I was ending with the non abrasive cork belt with green compound.
I also can’t get along with the vertical scratch pattern. I also can’t stand hand standing. I am sure Hitler is hand sanding in hell right now as eternal penance.
 
Hubert S. said:
I thought y'all have more sheep than people? Should be easy to find some felt, no?

I have a left-over piece (8"x2") that I'd be happy to send you if you cannot find any locally.
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Haha yeah should do. Probably send it all off shore!

I'll keep looking but may end up taking you up on that
 
Hubert S. said:
I have had success with Trizact A30, then cork. It took me a long time to get a uniform finish with cork belts. That's not the cork belts' fault, but my fault for not getting an even enough grind before going to the cork belt. When I first started, it would take me a long time to hand sand a kitchen knife at low grit to get the waviness out. I tried cork belts to reduce hand sanding time but that obviously did not help. As my grinds became more uniform, maybe seven or eight blades into this adventure, I was finally able to get a uniform finish with cork straight off the grinder. At the same time, it did not take much time anymore to hand sand a blade because I could go to 220 or 400 grit straight off the grinder. I spent some time trying to convince myself that a vertical scratch pattern is an acceptable finish on a kitchen knife, but was not entirely successful at that. I think it's not so bad on carbon steel knives as the patina hides the vertical scratch pattern. Recently, I spent a lot of time trying to get a uniform finish with cork belts in the lengthwise direction without success while the Scotchbrite belts works well for this. The Scotchbrite belts seem to have a lot of give and conform to the blade, the cork belts not so much. I like the cork belt finish better, though. It is hard to describe the difference, the Scotchbrite has a texture with longer scratches. They both give a nice satin texture, maybe you could call the cork belt finish "creamier".

Ok, that was a long back story to answer your question "where exactly do cork belts fit into the progression". For me, the answer is unfortunately nowhere. I cannot get a uniform lengthwise texture with them and while I like the surface finish they give me, I cannot bring myself to like a vertical scratch pattern. The progression I am currently using is P60/P120 ceramic, then Trizact A100/A65/A30 on glass and/or felt lined platen. I then use a medium and a super fine Scotchbrite belt in the lengthwise direction with a contact wheel. This gives a pretty nice satin finish, is quick to do and does not involve any hand sanding at all.
Click to expand...

I am just venturing into kitchen knife making and feel the pain with having to hand sand my way out of poor grinding skills. On the belt progression you state at the end of your post are you grinding all the way through the trizacts in vertical (perpendicular to cutting edge) orientation then switching to lengthwise grinding just for the scotchbrite belts, and that is eliminating vertical grind lines?
 
Colby L. said:
I am just venturing into kitchen knife making and feel the pain with having to hand sand my way out of poor grinding skills. On the belt progression you state at the end of your post are you grinding all the way through the trizacts in vertical (perpendicular to cutting edge) orientation then switching to lengthwise grinding just for the scotchbrite belts, and that is eliminating vertical grind lines?
Click to expand...
Yes, that is correct. I spent a good bit of time trying to get that to work and started a thread about it here: Lengthwise belt finishes on kitchen knives.

To summarize, I ended up buying a new medium grit surface conditioning belt and that belt does indeed take out the vertical A30 Trizact scratches. I use the Scotchbrite lengthwise on the bottom of a contact wheel. It takes a few passes with medium pressure. After the medium belt, I use a super fine to get a nicer scratch pattern. I got the belt only recently but have used it on four blades and got consistent results.
 
Hubert S. said:
Yes, that is correct. I spent a good bit of time trying to get that to work and started a thread about it here: Lengthwise belt finishes on kitchen knives.

To summarize, I ended up buying a new medium grit surface conditioning belt and that belt does indeed take out the vertical A30 Trizact scratches. I use the Scotchbrite lengthwise on the bottom of a contact wheel. It takes a few passes with medium pressure. After the medium belt, I use a super fine to get a nicer scratch pattern. I got the belt only recently but have used it on four blades and got consistent results.
Click to expand...

Thanks! I just read through that thread. Very informative. I'll add it to my list of things to try once I get a bit more adept at freehand grinding. I am glad you figured out a progression that is working for you!
 
Here’s a new Hermès RB515X Cork Silicon Carbide Polishing Belt 400

After an eleven minute break In. Does this look correct?


Webncth.jpg


i did a quick little test on a w2 blade
You can see the middle section where I ran the cork belt with Ultrapol compound
Next to it are Trizact A65 belt finish

Lp19ZYl.jpg
 
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