It’s hard to imagine starting with a piece of furniture that already looks good in its new space, and with the perfect paint color selected. Then, you start with your first coat and issues arise, such as a glossy area where the paint beads away, dust making your brush stroke feel rough, or a greasy smudge from old drawer pulls. None of these issues have anything to do with the paint color you chose. Often, they come from the surface.
Clean the furniture surface because dust on your brush is not the only thing you need to be wary of. Your hands leave residue on knobs, drawer pulls, table tops, and chair backs, and in the kitchen, even clean-looking furniture has thin greasy residue. Old wax, polish, and residue left from cleaning can also leave residue on furniture, causing primer and paint to not stick evenly. A simple degreaser, some rags, and a little time can make a big difference in your ability to make smooth brush strokes, not sliding, beading, and marking from your brush.
Before you start sanding, clean off the furniture, and pay attention to the rags. If they are leaving you a little bit of a gray, yellow, or greasy film on the rag, you need to clean it up more. Pay attention to areas you may not clean, like inside crevices, edges, chair legs, around knobs, and around drawer pulls and other hardware. Removing your knobs and pulls, using a screwdriver if necessary, can make it easier to clean them off, and there is usually a lot of gunk behind knobs, pulls, and other hardware. Leave your furniture to dry off so you don’t rub residue and gunk around while sanding. Sanding over damp, wet, or greasy areas can only move more residue around.
Sanding is not supposed to remove furniture down to its bare wood. You don’t have to sand every decorative piece until it is stripped bare to bare wood to paint it. Often in home decorating with little DIY experience, you just need to do some light sanding to dull the gloss and get a better base coat to grip, so primer sticks. A sanding block allows you to keep consistent pressure on flat surfaces, like the top of a desk, or drawers in a cabinet. Edges, and wood veneer, are more delicate; sanding over an area that has wood veneer can easily damage and remove that wood veneer, especially if you are putting too much pressure on your sanding block, causing uneven scratches, rounding over edges and corners that should have sharp corners.
It may even be worth it to do a test on a smaller, more out-of-the-way area like the edge that’s inside a drawer or behind a drawer to gauge how your furniture is reacting to sanding. Try the sanding block lightly on an edge or corner that is less noticeable and wipe away the dust with a rag, and run your hand over the area to see how it’s changed. You are not looking to feel your nail catch on any sharp edges, you’re just trying to feel the area before and after to see it is cleaner and slightly less slick. Once you are confident in the sanding you’re doing on the less-visible parts, you may want to move on to sanding the more visible parts.
Primer will also not apply as smoothly to dirty, oily, dull areas. Dusty or glossy surfaces can prevent primer and paint from bonding properly, resulting in an uneven coverage and peeling, or streaky finish, after basecoat. If you’re still having problems with coverage, do a second pass with a cleaner cloth and/or more sanding.
This doesn’t make for perfect projects or paint, but it gives you a better opportunity to do better with the other steps of your project. When you have paint applied, thickness of paint, stenciling, brush marks and dry brushing, distressing, water finish, wax finish, and final water-based top coat can be affected or made harder or impossible to do by not preparing your furniture first. The most important step is preparing the furniture before you apply the base coat for your main paint color and asking: is this piece clean, dry, ready, and not overly glossy? If your answer is any doubt or yes, then take a few more minutes now, to sand and clean this piece before you apply your basecoat.