- Raw or Not? The first step in how to paint wood like a pro is simply to determine if the wood is raw and unfinished.
- Covering Up - If the wood has been stained or treated, or if it is already painted, then other measures need be taken. Before you get started, you'll want to be sure you have covered up the floor with newspapers, rosin paper, cardboard or plastic. You should also be wearing clothes you don't mind getting dirty.
- Ventilation - Be sure you're in a well-ventilated area. If you are working in a garage, use only water-based products. The volatile fumes from some primers and paints can pose a threat with the pilot light from your heater or hot water heater. If you must paint in the garage, take precautions by using non-flammable products as you continue.
If the Wood is Stained or Painted
If the wood you are about to paint is already stained and finished, meaning there is a clear coat of urethane or lacquer or some undisclosed finish on it, then the first step is to wash the surface with a product called TSP, which stands for Tri-Sodium Phosphate.
There are no-rinse varieties of TSP, so you might decide to use this type. The idea is that paint needs a physical or mechanical adhesion. In other words, the best way for paint to bond to the wood is to bond with the wood grain. In the case of a pre-finished surface, it impossible to bond with the wood grain.
Even worse, a pre-finished piece of wood may have other impurities on top of the finish. There will be dirt from years of use, grease from hands, or food caked on the surface, between your paint and the wood surface. Painting over the impurities is a guarantee that your first coat will not last.
1. Sanding the Wood
After the TSP has dried and is either rinsed off or not according to instructions, the next step is to sand. Important: If your wood did not have stain or a finish on it, this is the first step in painting wood. Do not wash down raw wood.
Even if the wood was purchased factory-direct, don't think that the wood is ready to paint; it still needs a fine sanding.
- Get the Right Sander - If you don't own a random orbital sander, you can either purchase one inexpensively or rent one.
- Start Sanding - Begin sanding with at least a fine grit of 150, though beginning with a 180 or 200 is even better. The point in sanding is not to mechanically strip the wood of the stain, but rather to simply provide the paint with something to grab. Stripping finishes--as opposed to stripping paint--is a process used only if you want to re-stain the wood, in which case stripping and bleaching will be needed.
- Clean Wood - After sanding, thoroughly remove dust from the surface. A great way to do that is with a Shop Vac. Don't use a blower: that will only redistribute the dust back on the surface. Another great method is to use tack cloth or to wet a cloth rag with rubbing alcohol and go over the surface.
2. Priming the Wood
Why You Prime
Priming the wood prior to painting is not just an important step: this separates the professional grade paint job from amateurs. Primer is chemically formulated to bond to problem surfaces, and to give paint an even surface to bond to. It helps avoid problems such as flashing--where parts of the final paint job will look as if they were different sheens of paint. For instance, one area will look glossy, another flat, and altogether will look amateurish. Mix the primer well, and apply like you would a paint: brush, roll or spray on.
Type of Primer to Use
Depending on your final color choice, your paint manufacturer may have a particular primer base coat in mind. A properly chosen primer can really help you get your paint job done with using less paint.
Another tip to save time: have your primer tinted toward your finish color (if permitted by manufacturer's instructions). Make sure that the tinted primer is not an exact match for your eventual paint color; you just want it tinted in that direction. The reason for this is that, during the process of painting, you actually need to tell the difference between your final color and the dried primer.
Best Brands of Primer
Use a fine grade primer. Don't use the cheapest brand and expect to get great results. A couple of good brands are Kilz and Zinsser 1-2-3. Kilz provides several options, including a handy low-odor oil. Zinsser provides several selections, but also has a great shellac-based primer.