granite surface plate

Dunno if it's a good price either, and I don't know how hard it is to come by stuff flat to 0.0001"

I'm gearing up for Scarey Sharp, and I'm using a lot of chunks of what I think are granite counter backstop. Happens to be the right width for pre-cut 1/3 sheet sandpaper. It's as flat as my straight edge, however flat that is, and it was free. Dumpster behind a custom stone counter place. They throw away about four cubic feet of this stuff every day.

I'm heading that way tomorrow, to see if I can get enough chunks that I can have one dedicated chunk for each grit.

Want some? :)

Hi Todd, MSC Industrial offers the same size and tolerance for $23.99 plus shipping.

i consult for a granite and marble place here in MI. i strongly suggest you walk into a local facility that does stone countertop fabrication and ask for a scrap before you pay for a piece of stone.

our company pays $150 per day to discard tons of large, flat "scrap" pieces. so much material, in fact, that i am seriously considering building a large router table out of 2 1/4" thick granite.

good luck,

--- dz

todd wrote:

Hopefully, they'll ship that big piece of granite for $6 or less, otherwise you'll be better off getting it at Woodcraft.

todd

If you take two plates, spread some rubbing/polishing compound between them and slide one over the other, they'll polish out to flat (or spherical, one or the other). By working with successively finer compounds, you'll be able to get any degree of flatness and smoothness you want. Trade off cost vs work.

Mike

Hmmm...$30 or hours of rubbing two stones together, plus polishing compounds of various "grit". I guess if you want to make a point that it can be done you could go this way.

todd

If you do this with two plates, you'll get spherical surfaces, guaranteed. If you do it with three, you'll eventually get three flat plates.

Brian

you need 3 plates to make it flat. with only 2 plates you can make one match the other, but they won't be flat.

I'm getting the idea that $30 is a bargain.

todd

Pardon the newbie question, but what are the main uses/benefits of a granite reference plate?

The size of plate you are talking about in this thread seems too small to lap planes. All the scary sharp fans seem to go for a large piece of glass as backing for the sandpaper. I googled granite reference plates and see there are many sizes and "grades", but not much about the main uses a woodworker would make out of having one. Any feedback is appreciated. I have already learned LOTS by lurking on this NG for a few months. Regards, - Al

-- Mark

surface plates.

Judging by the reflections on those surfaces they are just a couple of granite slabs - the type that you would use for a countertop. Not the type that is flat to the 1/1000". Still they are rather flat.

-Jack

"JackD" wrote in news:bkpsi8$n7$ snipped-for-privacy@news01.intel.com:

Even better, judging by the thickness, or lack thereof, they are definitely

Those suckers are *thick*, like 3 or 4 inches for small surface plate.

Still, really nice pieces of granite, and a nice shop, to boot.

Regards, JT