Well, there are some products you don’t have to abrade between coats but let’s start with the finishes that do need abrasion.

Oil Based and Waterborne Polyurethane

This finish is in my opinion the best breakthrough for the clear finish world since clear finish has been used. This product was designed to mimic varnish. However varnish isn’t waterproof. Polyurethane is. The best way to describe oil based polyurethane is to think of it like liquid plastic.

Before you recoat this product you would need to abrade it or lightly sand between re-coats. Skip this step and your next coat will simply peel off the floor. It’s one of the most important steps because the light sanding allows the second coat to grip the coat under it.

The same issues apply to waterborne polyurethanes.

Chemical Bond Finishes

There are some clear finishes that don’t need to be abraded. Waterlox makes a tung oil varnish, which is a great product for high traffic areas. When a heavily trafficked area wears out you can just wipe an additional coat on that area. There is no need to abrade the floor first because the coats dissolve into each other. This is called a chemical bond. However it’s not foolproof, sometimes it will need to be lightly sanded just to clean it up a little and smooth out the scratches.

~ Floorman