View Full Version : What grade paper to remove metal by faux-lapping?

09-03-2006, 05:46 PM
Lacking a surface grinder, I need to put a clean, "ground" appearance on a 3" x 6" rigid steel part.

I need to first knock off about 0.0005 - 0.001" to clean up the previously ground surface before finishing with 400 - 600 grit paper on a surface plate.

What grit paper should I start with to knock off 0.001" in say, a half hour of patient grinding/lapping?

I realize that these are not lapping numbers but more of a light "belt sanding" magnitude of removal. Den

Your Old Dog
09-03-2006, 06:01 PM
I don't know if this answers your question or not but let me throw it out there.

When prepping some rifles for engraving I used to draw file the flat parts past the pitted areas. Then, using 1/4 ounch stiff leather belting as a backer, I use 220, 320, 400, very brief with 500 and then Happich Semichrome Polish on a hard felt pad. I could have your 3x6 inch piece of crs mirrior bright from a draw file finish in about 1 hour. Just make sure each change of sandpaper is applied 90 degrees to the previous and make sure you go thru each sheet until no 90 scratches can be seen from the previous grade. I used a black colored paper with a blue jean (indigo) color cloth backed purchased from the automotive store. I used wet sanding with water techinque. Some times I would use a new carborundum stone before going with sandpaper just to knock off some really high spots.

The secret is not to try and cheat.

good luck