Thread: Advice on purchasing a coticule

Congrats! Put the time into learning your stone and practicing - you will be happy you did. You will end up wanting more coticules Enjoy the stone, looking forward to hearing how the honing goes.

Congrats!

The prep that has worked best for me is to lap on 400 grit, then take the slurry stone and GENTLY rub the surface under running water, with the stone vertical. I like to use firgure 8 strokes and try to cover the surface of the stone evenly.

I usually take a 12k naniwa edge (or 8k, I have stone so I use it) and then do 50 to 100 laps.

dinnermint makes an excellent point that I too have followed.

I NEVER use a diamond plate for raising slurry on a coticule, only another piece of coticule as a slurry stone. Why? Coticules are made from larger garnet crystals (think glass) and sharp shards of diamond will easily fragment those garnets, leaving sharp pieces in the slurry or sticking out of the substrate. Gently using a cotigura (small coticule hone meant for raising a slurry) will be more likely to release the garnets from the substrate without harm and it is their round soccer ball shape that makes them work so well. I have no proof of course, but it seems to work for me, so that's my theory.

I do use a diamond plate to initially flatten a coticule (I did it once, maybe 15 years ago) and after that I have cleaned the surface with a cotigura and only use that for cleaning, raising a slurry or refreshing the surface. My coticule is rather hard and does not seem to auto slurry like many of them do, so it has not dished on me. But even if it did, it would have a long way to go based on the old hones we occasionally find that were used until they looked like a saddle.

Regards

Christian

Originally Posted by kaptain_zero

dinnermint makes an excellent point that I too have followed.

I NEVER use a diamond plate for raising slurry on a coticule, only another piece of coticule as a slurry stone. Why? Coticules are made from larger garnet crystals (think glass) and sharp shards of diamond will easily fragment those garnets, leaving sharp pieces in the slurry or sticking out of the substrate. Gently using a cotigura (small coticule hone meant for raising a slurry) will be more likely to release the garnets from the substrate without harm and it is their round soccer ball shape that makes them work so well. I have no proof of course, but it seems to work for me, so that's my theory.

I do use a diamond plate to initially flatten a coticule (I did it once, maybe 15 years ago) and after that I have cleaned the surface with a cotigura and only use that for cleaning, raising a slurry or refreshing the surface. My coticule is rather hard and does not seem to auto slurry like many of them do, so it has not dished on me. But even if it did, it would have a long way to go based on the old hones we occasionally find that were used until they looked like a saddle.

Regards

Christian

I do remember reading and seeing a magnification of the garnets when broken up with a DN vs coti slurry stone. It was advised not to use a DN for slurry, though many do and either don't notice a difference or don't know the difference.
It is in the article grinding and honing part4 belgian whetstones.

On my other stones I've only used sandpaper since at the time I didn't have a diamond plate, and that info is a good reason not to use one on the coti either. Generally I used 600 grit sandpaper followed by 1000 grit for the later stones.

Originally Posted by kaptain_zero

dinnermint makes an excellent point that I too have followed.

I NEVER use a diamond plate for raising slurry on a coticule, only another piece of coticule as a slurry stone. Why? Coticules are made from larger garnet crystals (think glass) and sharp shards of diamond will easily fragment those garnets, leaving sharp pieces in the slurry or sticking out of the substrate. Gently using a cotigura (small coticule hone meant for raising a slurry) will be more likely to release the garnets from the substrate without harm and it is their round soccer ball shape that makes them work so well. I have no proof of course, but it seems to work for me, so that's my theory.

I do use a diamond plate to initially flatten a coticule (I did it once, maybe 15 years ago) and after that I have cleaned the surface with a cotigura and only use that for cleaning, raising a slurry or refreshing the surface. My coticule is rather hard and does not seem to auto slurry like many of them do, so it has not dished on me. But even if it did, it would have a long way to go based on the old hones we occasionally find that were used until they looked like a saddle.

Regards

Christian

Now I kind of wonder if that isn't why my coticule is extraordinarily upset with me. Tried taking an edge up to 12K, then bumping over to my coti. Shave was awful. I lapped it flat with a diamond lapping plate, then 'burnished' it with the rubbing stone to get rid of the scratches. Maybe I still have broken garnets exposed. Hmmm...now the question is, how do I go about fixing that. Might be worthwhile to scrub it with the rubbing stone some tonight under running water.

Originally Posted by Marshal

Now I kind of wonder if that isn't why my coticule is extraordinarily upset with me. Tried taking an edge up to 12K, then bumping over to my coti. Shave was awful. I lapped it flat with a diamond lapping plate, then 'burnished' it with the rubbing stone to get rid of the scratches. Maybe I still have broken garnets exposed. Hmmm...now the question is, how do I go about fixing that. Might be worthwhile to scrub it with the rubbing stone some tonight under running water.

Just keep using it the right way and over time it will forgive you.

After lapping a coticule will be more aggressive and faster. It will calm down with some use and using the slurry stone under running water can help tame it again.

OK, dang it!!!!

Now you made me buy one

This place is FULL of enablers...................

Originally Posted by Dieseld

OK, dang it!!!!

Now you made me buy one

This place is FULL of enablers...................

Shoulda waited until I got home and finished messing with my coticule so I could tell you I hate these @#$% rocks.