DMT 325 Question(s)

[Bertilak]

OK, got myself a DMT325 as a lapping tool.

The directions don't make it obvious which side is the working side. I'm pretty sure it is the rough side not the shiny side but the directions confuse me. They show pictures of the working side as a lot of circles, but mine doesn't look like that at all, not even under magnification.

So, before I do something stupid, please confirm my belief that it is the rough side!

Second question, marginally related. Does a brand new Ardennes Coticule need to be lapped before use?

Thanks!

 

[Hawkeye5]

Correct, the rough side is the one to use.

I suspect any new stone needs to be lapped. I found my Shaptons needed it.

 

[Bertilak]

Correct, the rough side is the one to use.

I suspect any new stone needs to be lapped. I found my Shaptons needed it.

Thanks. Rough side it is.

About the coticule. It has obviously been worked on as the corners and edges are nicely rounded. The surface also shows marks as if it had been worked on as well, but that could be just from whatever they use to cut out the individual pieces.

Unless someone can jump in and say that the Ardennes definitely come pre-lapped I will give it a tune up with the DMT.

 

[huntmol]

The only way I can tell on some DMTs is to use whichever side makes the writing face up.

 

[ouch]

It's very hard to tell grit size with your fingers. As noted, the writing on the side should face up. Attach the little rubber feet so you never have to think about it.

And every stone needs to be lapped when you get it.

 

[Bertilak]

The only way I can tell on some DMTs is to use whichever side makes the writing face up.

It's very hard to tell grit size with your fingers. As noted, the writing on the side should face up. Attach the little rubber feet so you never have to think about it.

And every stone needs to be lapped when you get it.

Ahh -- the writing on the side. Another clue I should have heeded.

And thanks for the tip on the rubber feet. I didn't even know they were there. Had to pull apart the packaging to find them.

 

[SavantStrike]

Ahh -- the writing on the side. Another clue I should have heeded.

And thanks for the tip on the rubber feet. I didn't even know they were there. Had to pull apart the packaging to find them.

The other nice thing about the rubber feet is they are small enough not to get in the way if you use a hone holder, but just tall enough that you can stack the DMT with other hones .

 

[chess1]

use pencil mark to check your coticule lapped or not.

 

[Bertilak]

use pencil mark to check your coticule lapped or not.

I just lapped a Swaty I got off of eBay a while back. I figured I'd practice on the Swaty which I paid very little for before doing anything to the Coticule. As flat as it looked it was way off.

I drew some pencil lines on the Swaty and used the DMT325 on it. The lines came off of the center long before they eventually came off at the edges. I didn't time it but it probably took at least 40-45 minutes. Did it by holding both in my hands and working it in the sink next to running water which I periodically used to rinse away the "mud".

By the way, I emailed Ardennes and asked if their stones came ready to use or needed lapping. I was told no lapping needed right out of the box.