3M Wetordry sandpaper cuts fast and smooth, and it can also be used to repair surface defects. It can be used with water or cutting oil. Ideal for sanding metal for repainting or prior to primer coat.
3M 09085, Wetordry Sanding Sheets 9085NA, 9 in x 11 in, 400 grit, 7010383681, 5 sheets per pack
$2.99
Factory Stock, 7-10 Day Leadtime, Priced Per Pack
3M Wetordry allows you to sand between coats of varnish and paint or other finishes. Can be used with water to reduce clogging and extend abrasive life. Ideal for sanding metal for repainting or prior to primer coat.

3M 22397, Roloc Disc 361F, 60 YF-weight, TR, 1-1/2 in x NH, 7000045097
Standard Abrasives 78512, Ceramic Pro Type 27 Flap Disc, 645109, 4-1/2 in x 7/8 40 Y-weight, 7010301276
3M 45038, Wheel Adapter Kit No.3, 5/8-11 External, 7000028423 
