Thread: "Refreshing" a stone?

Came across info in another thread that it was necessary to periodically "refresh" a hone/stone. It specifically discussed a 12K.

I understand lapping, and I understand the need to periodically clean a stone. But what does "refreshing" a stone entail? How often is it done? Does it apply to all stones or just 12ks?

Thanks.

If i'm not badly mistaken lapping a stone is what is meant by refreshing.

I'm wondering if it may not also refer to breaking a glaze on a hone: breaking up the abrasives on the surface of the hone which have been smoothed and rounded through use.

Originally Posted by Bruce

I'm wondering if it may not also refer to breaking a glaze on a hone: breaking up the abrasives on the surface of the hone which have been smoothed and rounded through use.

That's what I was guessing too. But wouldn't lapping, which involves an abrasive material all across the face of the stone, do this? I don't want to lap anything too often, though. Would there be anything wrong with taking an old toothbrush and some shave soap to it once in awhile?

Some stones, shaptons for instance need to be lapped every time they are used. The polymer binder changes with temp and humidity variances and the surface moves. Some stones don't need to be lapped as often as that but I tend to lap them before use anyway. I can feel a difference. IMO water stones don't glaze if used properly, i.e. with plenty of water. I normally run water over the stone and rub with a plastic bristle brush when I am done. I think it is a good idea.

Originally Posted by Bruce

I'm wondering if it may not also refer to breaking a glaze on a hone: breaking up the abrasives on the surface of the hone which have been smoothed and rounded through use.

Yup, that's my take on it. Lapping is done to restore flatness while refreshing is done to improve the cutting power of the surface. They are done exactly the same way, it's just a matter of extent. That is, it takes little to refresh a surface, IF the stone is already flat. If you try to refresh the surface of a hone that is not flat, then you are only refreshing the high spots of the hone until you lap it back down to flat. The Norton stones benefit from frequent refreshing/lapping both because use causes them to become non-flat and because the surface quickly can fill with swarf.

The Chinese hone seems to be the most prone to glazing. Its minimal cutting power is reduced further without occasional refreshing. I don't know if it's due to razor swarf or to the surface breaking down. On the bright side, the stone is so hard, once it's lapped, it should stay flat so it should take minimal effort to continually refresh it. Finally, frequent refreshing also provides the added benefit of continually keeping the hone flat.

Originally Posted by pcb01

That's what I was guessing too. But wouldn't lapping, which involves an abrasive material all across the face of the stone, do this? I don't want to lap anything too often, though. Would there be anything wrong with taking an old toothbrush and some shave soap to it once in awhile?

That's not going to remove the glazing. Refreshing removes very little stone surface. Unless you go into uberhoning, your hones, even with frequent refreshing, should last longer than you will.

The first suggestion I came across that talked about "refreshing" the surface of a hone was a collection of articles on woodworking. The author told how and why he would periodically "refresh" his Arkansas stone. He wanted to remove any built up "swarf" and also to resharpen the cutting edges of the grains. In an Arkansas stone, which is so hard, the quartz edges become smoothed over, rounded, rather than fracturing and exposing a new edge.

From that article I learned that a stone can accumulate debris, swarf, that reduces the cutting power, abrasiveness, of the hone and also that an abrasive grain can become "rounded".

So, I started lightly lapping my hones. I used various grits to accomplish this. I have finally settled on using a 1000 grit Norton that I have to lightly lap my hones just before each honing session. I perform maybe 10-15 laps under running water until the surface is uniform in color and texture. Now, I find that I may also refresh the hone while I am honing. That normally occurs when I am using the Norton 4K which is my workhorse hone.

I will probably start refreshing my finishing hones with a 4k in the future. A 1k texture/surface seems to be a bit to much ....maybe.


Hope this helps,