wet grinder/polisher?

[mikeina]

Hello Everyone!

This is a bit off topic for this forum, but I'm having trouble finding information and hoped you all would be willing to help out. I am an artist and paint on rock, a variety of different kinds of rock but mostly limestone. I take a fairly flat rock and grind a smooth area for the painting. I am not trying for a high polish, just smooth with no visible scratch marks. I am looking for a better tool to suit my purposes, and am trying to figure out if a wet grinder/polisher would be it, before I put out the $.

To date I have been using an angle grinder with a masonry wheel and then sanding with a palm sander. It's satisfactory but I wish it were better and it's very slow to get the results I want.

So...a few questions:

1) Will the addition of water make a big difference? How?

2) I assume I will need to use the diamond polishing pads, any guess on what grit to work up to? Maybe 200? or would that still leave marks? Would a higher grit be too polished?

3) Would I benefit from having a variable speed grinder/polisher?

4) Is there a different tool or process that would suit my needs better?

That's all I can think of for now,

Thank you for your time, and any advice you may have.

	Polishing Polishing: This is the final stage, which leaves the surface with reflective characteristics.

	grit GRIT SIZE: Applies to the size and number of particles per square inch which are used to determine the abrasiveness of sandpapers, grinding stones etc.

	limestone LIMESTONE A sedimentary rock composed of calcium carbonate.

[cheesedog]

cant go wrong with something like the FLEX waterfed variable speed. its about 400 bucks, but has a waterfeed through the center and goes from 800-2000 rpm, should be fine for what youre doing. i like water because there is no dust, but if youre in someones home you have to tape off walls and such.
depending on what stone youre working on you can start to get a reflection after 200-400. on limestone you probably wont see it till 800. if you looking for just a flat smooth finish with no reflection 400 should be fine. a copper bonded disc would be good for light shaping, rounding corners etc. for a very even, smooth finish with no marks you can finish with honing powder.

	Honing Honing: This is the third and sometimes last stage. At the hone stage, the surface is ~65% scratch free. There are several degrees of hone. All will leave the stone looking clean but aged.

	limestone LIMESTONE A sedimentary rock composed of calcium carbonate.

[mikeina]

Thank you for your reply. I'll have to learn about honing powder, thank you for the suggestion. Could I get away with using the honing powder in place of or after my sanding step and skip the wet grinder/polisher completely? Once the stone gets to the reflection stage I think I will begin to have problems with the paint adhering, I need to leave a little "tooth".

Originally Posted by cheesedog

. for a very even, smooth finish with no marks you can finish with honing powder.

	Honing Honing: This is the third and sometimes last stage. At the hone stage, the surface is ~65% scratch free. There are several degrees of hone. All will leave the stone looking clean but aged.

[cheesedog]

the honing powder is used as a final finish, like polishing, but for a satin finish, it is not designed to be used in place of any diamonds. for the paint, the honing powder may be too smooth, maybe you can paint after 200-220 grit, then sand smooth then paint from there.

	Honing Honing: This is the third and sometimes last stage. At the hone stage, the surface is ~65% scratch free. There are several degrees of hone. All will leave the stone looking clean but aged.

	Polishing Polishing: This is the final stage, which leaves the surface with reflective characteristics.

	grit GRIT SIZE: Applies to the size and number of particles per square inch which are used to determine the abrasiveness of sandpapers, grinding stones etc.

[mikeina]

Ah, got it, thanks for the clarification. I can't paint, sand, paint. I'm starting to think that it is the diamonds that will make the difference from what I have been doing.

[Huligar]

Here is my 2 cents, keep the tools that you have. Add a ridged backer, grits 50 - 1000, and get a get a spray bottle. With this set up you can get a low hone with out any scratches to a high hone with a reflection but not a polish. If you wish I can recommend some great and inexpensive diamonds to this job.

[cheesedog]

for the sake of saving money....^ what he said ^

[mikeina]

Thanks, I don't mind spending the money, if I could know it would do a better job.

cheesedog, thank you for all your input, I appreciate it.

Huligar, yes, please make those recommendations, sounds like a good compromise for now, might show me I really do want to spend the money on the better set up.

The angle grinder I have been using is single speed, probably 10,000 rpm, will I be able to use it?

[Huligar]

Here are the pads that I would use on a 10,000 rpm
http://www.nsraweb.com/store/cart.ph...ct_detail&p=21

[mikeina]

Thanks for your indulgence folks!
Now back to your regularly scheduled programming