stoning the table

[bigtoad170]

I've always used old broken very fine surface grinder stones to stone off any nicks and dings that may be in a table this probably isn't the true tool to use any tips on the proper tool and procedure to do this.

[toastydeath]

The material itself is called an India stone, and they come in pairs or singles (slips). They are ground pretty darn flat to keep the machine table/whatever in good condition. You rub a pair together to keep the stones themselves flat and clean.

[bigtoad170]

do you usually use some kind of oil with the India stones or just dry

[toastydeath]

Dry. You can use water to clean them, but let them dry before you use them again.

[holbieone]

wd-40 works good

don't put a lot of pressure one the stone

just let it glide over the table ,and it will find the nicks and dings

work that area until the stone glides there too

[mxtras]

Using a fine India stone, it would take a few years of constant rubbing in the same area to remove enough material to be detrimental to the table, but it will take a high spot down pretty fast. It's a common practice to use a medium bench stone for this. The medium stone will cut, but the flatter the surface gets, the less the stone wants to cut and the more polishing it does. The idea is to identify and remove high spots, not remove material from the table. Even using a medium bench stone, it would take quite an effort to remove much material from a flat surface - even .0005" would take quite a while.

Dry is fine but the stone will plug up. A splash of light oil is all that's needed to keep it clean - WD-40 works.

Scott

[bigtoad170]

thanks fellas

[HuFlungDung]

Originally Posted by toastydeath The material itself is called an India stone, and they come in pairs or singles (slips). They are ground pretty darn flat to keep the machine table/whatever in good condition. You rub a pair together to keep the stones themselves flat and clean.

Has anybody owned a pair of these India stones long enough to find out that rubbing two together does not guarantee flatness? For that you need to have 3 stones lapped to one another.

[toastydeath]

Originally Posted by HuFlungDung Has anybody owned a pair of these India stones long enough to find out that rubbing two together does not guarantee flatness? For that you need to have 3 stones lapped to one another.

Good thing they come with four surfaces.

[HuFlungDung]

Doesn't help, since you cannot lap one side to the other side of the same stone, it is not possible to guarantee that one has not become concave and the other double sided stone has two convex surfaces (or vice versa).

[toastydeath]

Originally Posted by HuFlungDung Doesn't help, since you cannot lap one side to the other side of the same stone, it is not possible to guarantee that one has not become concave and the other double sided stone has two convex surfaces (or vice versa).

You can generate four flat surfaces with two stones, you just need all four surfaces to do it and the process is more complicated.

[HuFlungDung]

Nope

One stone will have both sides identically concave, and the other one will have both sides identically convex.

Its probably better to reserve one side of one stone for use only for table stoning and never use it for anything else. Chances are good that it will stay as flat as the machine table.

Given stones of approximately equal size, working one stone on top of another inevitably renders the top one concave and the bottom one convex. This is due to the natural force of gravity, plus the effort of the man doing the pushing, overworks the center of the top stone, and the edge of the bottom stone.