: I need to knock down some drips/runs before final fill coat of epoxy. I
: scraped the most obvious offenders, then attempted to sand, using a ROS
: hooked to a shopvac. It works, but.... that epoxy plugs the filter very
: quickly. Any suggestions? I'm thinking I might be better off wet-sanding
: this. I presume a respirator is still necessary, even with the 'wet'.

Scrapers are wonderful tools which remove tiny curls of resin. For many drips and blobs a scrape is too delicate of a tool. While they epoxy is still young, use a sharp plane to get rid of the bumps from runs and drips. You'll get shavings of plastic rather than a fine dust.

Wet sanding helps prolong your sandpaper, but probably won't keep the shop-vac filter from plugging up. But it won't hurt to try. Another thing to try is using a coarser grit sandpaper.

There are special shop-vac filters to use when sanding drywall. One of those might handle the fine powdery epoxy.

Or, forget the vacuum and the power sander. A sanding block with fresh, coarse or medium grit sandpaper acts like a big eraser to rub out those errors. Keep a damp rag in your other hand, and wipe the area you are working on when you start building up dust. Hand sanding puts less dust in the air, too. I'd throw away the rag after using it for this.

A big yes to using a respirator.

PGJ