Thread: Naniwa Bulge

did you check your dmt with a straight edge my 1200 is out pretty bad a flat piece of glass is better with wet paper

if only lapped for a few seconds the center could only be up a tiny bit; a few more seconds may show flat.

it could be your technique. Is it two hands under faucet? try using one stone stationary bench top method. (just because the grid is gone does not insure flatness. I think we can trick it with hand pressure etc unknowingly)

the longer you go between sharpening the more the stone can move. especially if you are soaking as it goes from super saturated to EMC.

you can use a granite tile to check the plate(and stone) by grafite_ing the tile and rubbing over.

lots of possibilities listed by all of us, start eliminating and let us know what's left

I believe my lapping plate and my technique are both ok. I don't get this bulge-pattern on my GlassStones.

I let the Naniwa dry out for a day and now it has a slight hollow in the middle where the bulge was. So I'm becoming more convinced it is related to wetting and drying, perhaps aggravated by the fact that it is a thick and porous stone. I think I will start lapping it as dry as possible and use it with as little water as possible. Maybe that way it will maintain a more stable surface.

Originally Posted by matt321

I believe my lapping plate and my technique are both ok. I don't get this bulge-pattern on my GlassStones.

In that case it isn't the diamond plate. I hope you get it sorted out.

Originally Posted by matt321

I believe my lapping plate and my technique are both ok. I don't get this bulge-pattern on my GlassStones.

I let the Naniwa dry out for a day and now it has a slight hollow in the middle where the bulge was. So I'm becoming more convinced it is related to wetting and drying, perhaps aggravated by the fact that it is a thick and porous stone. I think I will start lapping it as dry as possible and use it with as little water as possible. Maybe that way it will maintain a more stable surface.

Not knowing if you're talking about the Superstones or the Choseras...
But I personally deal with the issue the other way round. I only lap and use my Naniwa Chosera 10K when soaked at least 15 minutes (usually longer). Beware: Naniwa advices NOT to keep the Choseras submerged all the time, so I don't do that.
I find the Chosera's performance less good when they are not properly soaked. Don't know about the Superstones.

Bart.

I think most of us assumed it was polymer movements. Hate that when it crops up as I usually try to ignore it.

Technically even nats are polymers.. I wonder what sort of movements occur that we don't keep track of

I also wonder if the base contributes to the problem any?

if you live in a very cold place (sub zero) water in the stone will expand when it freezes just my two cents.