Thread: Restoring an old Coticule

Thank you all for the really useful tips! I found amazon uk sells a 4 sided diamond block for around 11 pounds, grit range from 200 - 600.
Have purchased it and will see if I can salvage coticule waste.

Thanks thebigG for comment on BBW... I am a little worried that if I take too much off I could end up with a very thin stone that might break... I am considering very small X strokes to get around damage on stone... Hmmm

Just use wet/dry sandpaper. Do most of your work with a 120 grit and finish with a 220 & 500.
The flaws in the BBW an be sanded down ( smoothed over) or lap it all the way out.
I would forget about trying to save the slurry. It will be contaminated no matter what you use.
Besides, there are much finer abrasive powders you can purchase.

Just my 2¢

I save slurry from my Jnats for other use, an broken in DMT or any good diamond plate won't contaminate it in the first place.
Make sure the diamond plate is broken in (no loose or high diamonds), no dirt on the stone, clean hands and a bucket of clean water.
Lap the stone under water or well wet at least, let the powdered stone collect in the bucket, pour of as much water as you can and let the rest evaporate.

Had a girl over helping me clean once, she cleaned out lots of small plastic containers with "some dirt" in them... Nakayama dirt!

Lots of life left on that stone, lap with a diamond plate on a cookie sheet. That stone will lap quickly, cover with a cloth, let the slurry dry and you can collect it, there won’t be that much powder, though.

If you use sandpaper, even wet & dry, Randy’s right, the powder will be contaminated with the grit from the sandpaper.

100 -120 grit drywall sanding screen on a cement slab is the fastest way to get to flat, finish on a diamond plate. Smooth is more important than perfectly flat.

Once lapped, you can begin to learn the nuisances of the Coticule. There is a lot written on the Coticule and much to learn.

Enjoy

Hmmmm, diamond plates do not wear down? I must have purchased some bad ones.

Originally Posted by randydance062449

Hmmmm, diamond plates do not wear down? I must have purchased some bad ones.

They don't?
Mine do but if they are broken in and used with water they don't release any stray diamonds!
That's until they get really old and used up...

Originally Posted by Lemur

They don't?
Mine do but if they are broken in and used with water they don't release any stray diamonds!
That's until they get really old and used up...

My point is that the diamond plates do release fragments of the diamond grains thruout their use. I am not saying that the entire diamond grain is released, just a fragment. Thus there will be some that ends up in the slurry.

Originally Posted by Euclid440

Once lapped, you can begin to learn the nuisances of the Coticule. There is a lot written on the Coticule and much to learn.

I hope you meant "nuances." But Lenahaad, be forewarned, not every coticule is a great coticule. Some aren't even very good. But if yours was dished, then someone really liked it and it's probably a good one.

About your four-sided diamond block--check each side with a straight edge before you touch it to any hone. I bought a lower-price plate once and discovered it was quite far from flat. I'd have ruined hones, or at least lost a lot of them before getting them flat again, if I had used it without checking. The DMT plates are reliably flat, as are the more expensive Atoma and some others. DMTs are probably the least expensive reliably flat ones. (DMT = "Diamond Machining Technology"). Beware lapping at 600 grit; the diamonds that small are more likely to get sheared off their plate by lapping. Do the heavy work at 350 or coarser, then just put a light polish on with the 600 if you want to.

Best wishes.

Spell Checker victim, though as you said… they can be. And then there is the collecting…problem.

Be careful with inexpensive diamond plates, you can use them to hog off material or bevel edges, but they can have diamond clumps on them. Run them on some hard steel first to knock off any high spots and prevent gouging, an ax or shovel tip.

Finish on a good diamond plate like a DMT or wet & dry sand paper. That stone is not that bad and I would not risk it. Sanding screen and Wet & Dry is the most economical answer.

I have seen 2 of the DMT plates that were not flat. Be sure to check them.