Thread: Coti and Backside

So, at dinner the other night, my brother goes to sharpen his carving knife, and pulls out his "worn out old sharpening stone"
I did a double take as he started drawing the blade across a very very well used coti!

Needless to say, I convinced him to give this up to me as part of a trade. (I gave him a nice new carborundum stone)

Its way harder than I thought it would be, and looks like polished marble. Its terribly dished. The corners are after 5 minutes of circles on a piece of 220 grit emery.
I will win over this stone eventually, but, I have 2 questions...
1) should I be keeping the "dust" to make slurry with in the future? or might the metal dust mixed in with it from years of knives be a detriment?

2) the backside is heavily gouged. Is it worth it to clean this up, or is the backside not really made for honing anything and its just some kind of backing?

I don't know about keeping the slurry since the sandpaper might contaminate it. Even if it didn't. .... some guys do but mine goes down the drain as I lap in the sink under running water.

If that is a Belgian blue (bbw) it is well worth using (with slurry). If it is slate it is only a backing. Looks like blue. If you lap and slurry is purpulish it is a bbw. If it is gray it is slate. From the photo I cannot tell if the stone is a natural combo or glued. If there is no glue line it is bbw. If there is a glue line an older one would be bbw and a later (still old comparatively speaking) would be slate.

Most certainly glued. I will have to slurry it up a bit I guess, and see about the color. =)
What if I use the DMT instead of the emery? is it only the contaminate from the grit that is an issue? or the steel bits are mine enemy as well?

Originally Posted by Magpie

Most certainly glued. I will have to slurry it up a bit I guess, and see about the color. =)
What if I use the DMT instead of the emery? is it only the contaminate from the grit that is an issue? or the steel bits are mine enemy as well?

A DMTC or XX is fine for lapping and I don't think that there will be any contamination at all. If you have either of those plates by all means use one of them. Nice coticule BTW. Looking at the color on the side of the yellow it is the same as a really good one that I have.

Originally Posted by JimmyHAD

Looking at the color on the side of the yellow it is the same as a really good one that I have.

+1. If your white balance is adjusted right, you have the coti that I've been looking for.

Back side makes a wonderful purple slurry. white side is being a bear to scrub down. If you want, I can take another picture, and see how close I can get it on my screen to matching actual color. If you really think it might be "the one" I could send it to you to play with for a bit.

I never actually actually tried honing on my backside. I've got some really rough spots on my elbows and heels I can use for finishing if I have to, but I save my backside for stropping.

Originally Posted by stimpy52

I never actually actually tried honing on my backside. I've got some really rough spots on my elbows and heels I can use for finishing if I have to, but I save my backside for stropping.

You really need to flatten it .

My dad used to use my ass like a razor. Stropped the living hell out of me with that latigo!

what a nice conversation, stropping children with latigo. I will have to keep this one in mind when my girlfriend gets sassy again.

Buuuuuut what I was about to ask is,
how do you lap your coticule, if you´re able to collect dust?
Are you lapping it dry, cause I wouldn´t recommend that especially on a DMT
because of increased wear.
Instead of collecting dust you can actually go and slurry the Coti
with your DMT everytime you want to use it.

Nice Coti you have there, btw.