nice big lapping plate

[kohalajohn]

Finally got the stuff to build the lapping plate I want.

Acrylic one inch thick, and the size of a full sheet of 400 grit sandpaper, being 9x11

So I can slide the stones all over it and not worry about missing out on edges.

A 12x12 floor tile would also work, but I like that the acrylic is transparent and I can see what grit it is just by looking through the back.

photos attached

 

[David]

Is the acrylic flat?

 

[Slash McCoy]

Nice. David brings up a good point tho... did you check it for flatness? I am almost positive that it will be flatter than a floor tile but nice to know for sure. I never thought of that, being able to see the print on the back of sandpaper. I think maybe I will make up a couple of them when I get home. 1" thick, good move I think. Hey, it can't wear out or go bad on you. Should last forever so cost isn't a dealbreaker. And still way cheaper and handier than a granite lapping plate even if it isn't flat to the nearest .00001" LOL.

 

[kohalajohn]

Yes it is.

These are cast acrylic plates. They are not ground flat like stones are, but are poured as a liquid, so are flat the same reason a sheet of glass is flat.

Cast Acrylic Sheets Cut-To-Size : TAP Plastics

I also buy them in 3x12 inch size. put 1200 grit sandpaper on it and you have a bevel setter than never dishes. You can use acetone to remove the used up paper and the glue, and it doesn't harm the acrylic.

put your pasted balsa strops on it and the balsa is held firm and also you can hone in the air without risking nicking your fingertips. same benefit for really thin finishing stones. protect yer fingertips

I used to use tiles and wood for this, but I now like acrylic better.

photo of several of the 3x12 cast acrylic tiles, that just arrived. the paper on it is just for shipping. you peel it off.

 

[Seveneighth]

Nice. - very clever.

 

[eKretz]

Having personally flattened plenty of glass plates, glass is often far from flat. Check them.

 

[kcb5150]

If you were made out of money or had to lap enormous numbers of rocks, paving a flat slab tile or flat slab of metal with replacement atoma blades into some massive continuous surface would be glorious. Overkill, but glorious.

 

[David]

If you were made out of money or had to lap enormous numbers of rocks, paving a flat slab tile or flat slab of metal with replacement atoma blades into some massive continuous surface would be glorious. Overkill, but glorious.

I’ve thought about doing this a hundred times. A flattened slab of granite and a whole sheet of atoma 400 would be pretty freaking awesome.

 

[timwcic]

A nice, big lapping plate courtesy of the dumpster at the local granite countertop fabricator. Ground and polished, 20x30x1.5 Inches. Hold a hole sheet of W/D with room to spare. The down side is it is not very portable or comfortable in the rain

 

[kohalajohn]

Ok, Tim, well, that is a big damn lapping plate. You could flatten a golden retriever on that.

About the flat question. I had replied about the flat question before I saw Slash's response.

And yes, I had assumed the acrylic would be flat, because they have been flat before. But yeah, I should have checked for flatness anyway.

So I just now went downstairs and put my square on it. Not a carpenter's square, a good machinist's square. Held it up to the light, turned the square this way and that way.

Yup. It's flat. As the eye can see. And my eyesight is good and the square is good. I mean you take anything enough decimal points to the left and you find quantum weirdness. But it's flat. The square was flat on it on all the planes.

I"ve got a big pack of 400 grit sandpaper sheets. I don't need to think about lapping plates again.

Hey you soft synthetic stones, welcome to a world of flatness, of no more dishing on me, ever. How do you like being the bitches of acrylic now huh?