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.

Dynabrade 90874 2" Dia. Very Fine NWN DynaBrite Locking-Type Disc, 25/pack
3M 06728, Premium Plastic Sheeting with 233+ Masking Tape (36 mm), 16
ft x 400 ft, 7100139893
Dynabrade 10690 Filter/Regulator/Lubricator, FRL40, 1/2" NPTAssy.
Dynabrade 96101 Dynabrade Air Lube 10W/NR 24 Per Box
Dynabrade 13509 Dynastraight Finishing Tool, Rear Exhaust, 6,000 RPM, 5/8" (16 mm) or 1" (25 mm) Dia. Arbor
3M 17227, Heavy Duty Duct Tape DT11, Silver, 48 mm x 54.8 m, 11 mil, 7100158346 
