Preparation is the key to a good paint job and plywood is no exception. Before you start painting, take your dustpan brush and give the plywood surface a good dust down to clear away any debris.
To get a smooth surface, you need to fill up any holes. Mix some builders bog up with some hardener on a piece of cardboard with your scraper or putty knife. The more you use, the quicker it's going to set so you need to work fast.
Once you've mixed it together, use your scraper to fill the holes with it. If you're fussy about the edges of your plywood and don't want to see the end grain, apply the builders bog to that too.
Once the wood filler is dry, give the surface a light sand to make it smooth. Make sure you wear your dust mask and ear muffs for this step. When you're finished, wipe away any excess dust with your dustpan brush.
Mask any areas that you don't want covered in paint with some painters tape. We want to keep the raw timber look around the edges, so we've masked them. This will prevent paint splatters or smears.
Before you start painting, put down a drop sheet to help keep the area clean. Then give your paint a good stir. Depending on the paint, you might need to apply a primer, but we don't need to do that with the paint we're using.
Next, apply your topcoat. We just want to apply one coat, because it's an outdoor workbench, which only needs waterproofing. Remember to apply the first coat in the direction of the grain for a smooth, even finish.
To apply more coats, leave the paint to dry first. For a better finish, give it a light sand between coats and wipe away any dust. Also, paint in a cross-hatch a pattern.