Learn How to Paint Wood Smoothly Like a Professional

Painting wood chair
Exterior items like chairs benefit from an annual paint job. Michael Möller/EyeEm/Getty Images

Are you painting wood? You may be doing it the wrong way. One reason is because wood painting seems like such an elemental, basic foolproof task. What could go wrong?

With the advent of paint-ready surfaces like wallboard and pre-primed trim and casing, wood painting is slowly becoming a lost art. Mastering these techniques can transform you from a amateur weekend painter to a professional-quality painter, in no time at all.

1. Cover Up the Right Way

Treat the covering up stage seriously. Use the right materials and take time laying it all out. Also, use the right kind of protective materials.

  • Wrong: Plastic sheeting, cardboard scraps, newspapers, bed sheets do not work well because they are either too slippery or they permit paint to seep through the material.
  • Right: Use canvas painter's dropcloth or inexpensive kraft paper called contractor's or builder's paper. Put plastic sheeting below to prevent paint from permeating through and onto the flooring.

2. Clean the Surface the Right Way

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, the first step is to wash the surface with a product called TSP (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 good 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. So, make sure that these types of surfaces are especially clean.

3. Sand the Wood the Right Way

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.

    4. Prime the Wood

    Priming the wood prior to painting is not just an important step: this separates the professional grade paint job from an amateur job. 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, a condition where parts of the final paint job will look as if they were different sheens of paint. For instance, one area will look glossy, while another will look flat. Combined, it has a very patchy, unattractive appearance. Mix the primer well and apply by brushing or rolling it 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 high quality 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 version.  Zinsser provides several selections, but also has a great shellac-based primer.

    5. Sand a Second Time

    You will need to re-sand after priming raw wood or even if you're painting wood that has been stained. Primer isn't going to be smooth, it will need to be sanded down smooth. Not a lot of pressure will be needed.

    Your final piece should be nice and smooth to the touch when you're done. This step will really pay off. Like the last step, you'll want to get rid of the dust either with a vacuum or with a tack cloth.

    6. Paint the Wood

    Choose the Paint

    Be sure that you choose the right paint for the job. Don't use an exterior grade paint indoors or vice versa, and don't use flat paint unless you don't care how dirty the surface will look after a while. At least go with an eggshell or satin, if not semi-gloss or gloss. There are new washable flats on the market that are preferable to the traditional flats.

    Purchase the Correct Painting Tools

    Purchase a quality brush. Recommended is a Wooster 2-inch brush, the kind that will paint latex or oil, or a similar brand. Beware of generic brands, as they may shed their bristles all over your wet paint.

    Get a bucket with a roller screen for large-scale projects. For single room jobs, purchase a paint tray, paint tray liner, and screen. Screens force more paint out of the roller and conserve paint, thus saving money.

    Make sure the roller pad or roller cover you get won't shed, especially if you're using a higher gloss paint.

    Begin Painting

    Get your roller arm damp by rolling it down onto the surface of the paint but do not submerge it. Then roll it out onto the screen in the bucket.

    Spread the paint on the wood by using a "W" pattern, then quickly take your brush, with the tips only dipped in paint, and paint along the direction of the grain. The trick is speed, and not to re-work what you've painted once it's begun to dry.

    Avoid Tackiness

    If you have a hard time with the paint being tacky or wanting to drag your brush, then you can either pick up the pace or buy a product that extends open time. You also want to be sure you're not painting underneath a fan or heater vent, or in open sunlight or wind. These can all contribute to faster tackiness. One product that extends open time is Penetrol, strictly for use with oil paints. An extender to use with latex paints is Floetrol.

    7. Sand and Paint Again

    You can usually achieve an even smoother coat if you opt to sand and paint one final time. Sanding your previous paint coat brings down bumps and inconsistencies introduced by the roller or brush. Use a very fine grain sandpaper, such as #220. Attach the paper to an orbital sander and run it lightly across the surface. Do not apply pressure to the sander other than the weight of the sander itself. 

    After sanding, open up your tack cloth, bunch it up but keep it loose, then lightly run it across the surface. Too much pressure on the tack cloth will be counter-productive, as this will press wax onto the surface. Now, the wood should be clean and smooth to the touch.

    Finish with a final coat of paint.