Question: restoring a ceramic lap

I've used acid on mine and it came out snow white as someone else described, but the problem was that it was clean and white but still performed like before. So there's more to it than just making it white. Jan's method of removing the top layer and getting down to fresh ceramic sounds like the best way to restore a ceramic lap to like-new condition.

The Method described by Jan is the same that i was using for flattening sides or walls in Casting glass sculptures, circular movements help in have a better flat uniform surface, never thinked that can be used for this purpose but is a good idea thank you for the tip!

Jan, thank you for the tip, I will try

My good GRS lap fell on the floor and you know what. Then I made the mistake of buying one on Ebay for only $100.00. It looks good but has a grit to it and will not polish like the good ones. I know I will have to spend the $199.00 soon for another good one. Don't make the same mistake I did. I'm supposed to know better but every now and then I do it again.

The manual that comes with the GRS ceramic lap says you have to clean the lap when it becomes a bit black. Also that you have to spray it with the water based diamond powder spray.
I used to do so when I started using all my new tools.
But now a days I don't see much of an advantage when the ceramic lap is cleaned. Neither do I experience any better results using a ceramic lap with fresh diamond spray.
In fact when I think about it, compared to a iron casted lap, the ceramic lap is much harder. A ceramic lap need to be "loaded" with diamond powder without water. So when the ceramic lap becomes what is called "dirty" it still polishes the gravers very well. When using the ceramic lap to polish the face and heel, I do not add any extra diamond spray. I see no reason why as it keeps polishing nicely like what the lap is meant for.
And when I think about it, at the time the ceramic becomes what is called "dirty", in fact the lap is well loaded with diamond powder. you can use it without having to add extra diamond powder.
So try not to add too much diamond spray, don't spray it every time you use it, and once the ceramic lap is nicely "dirty", you use it just like it is. Once a week I might spray once with the diamond spray.

Same with the casted iron lap, you could clean it once in a while, but I never did and it only polishes better and better. I just use a dry paper towel to clean the dust .

just my two cents, arnaud

I am fully agreed with Arnaud, just want to add from my site, that I am using metal roller to push down diamond powder.

How about a light sand blasting, would that renew the surface.

Kind of a crazy thought but what about a super heavy duty magnet, kind of like a lift magnet or an electronic magnet like the ones that hold work pieces in place during the machining process?

Now I know that the fine particles are embedded in the ceramic but some of these magnets can lift 2,000 lbs... would be interesting to see if someone had access to one of these expensive magnets.

I think running one through an MRI might not do much of anything to the surface texture of the ceramic?

Maybe remove a little metal...


They will definitely look at you strangely, if you insist that it ride through the tunnel with you.


Brian

I was wondering if Jan might be able to share a source for the 400 grit silicon carbide. I would like to try his technique. I have yet to be able to find the silicon carbide grit. I hope you're listening Jan.

This is kind of crazy discussion.
If you want more grit,go to an different stone.
Its is not an grind stone,its an polishing type stone.
I use the spyderco ceramic bench stones.
I clean with borax powder and water,sometimes a brush sometimes an finger.
The key is DO NOT use oil or grease,WATER with detergent,or just water.
They have 3 diff. grits med fine and ultra fine.

michael
P.S. You cant actually "load" the ceramic stone like the cast iron "LAP".

Andy said:

I was wondering if Jan might be able to share a source for the 400 grit silicon carbide. I would like to try his technique. I have yet to be able to find the silicon carbide grit. I hope you're listening Jan.

Click to expand...

This is really for flattening the stone,not to raise the grit.
The grit is what it is.
And as far as i know,its pretty hard to dish out an ceramic stone,especially the hard white ones.

3M wet/dry sand paper is silicone carbide
I think the Norton india stones are silicone carbide.
They also make grind stones of this.
I bet they even sell powders.



michael