Tips for Spray Painting Baseboards With an Airless Sprayer
Spray Painting Baseboards vs Paint Brush Application
If you don't want to spend the day on your hands and knees painting baseboard trim with a brush, use a paint sprayer instead. Even for a newbie, baseboard trim is easy to spray paint, using an airless sprayer, equipped with the right size spray tip.
Spray painted baseboard has a smoother finish, and while you can certainly achieve a smooth finish too using a quality paint brush, the sprayed look is superior when done right.
Unlike spraying door jambs, where airborne paint particles blow all over the place, the over-spray from spray painting baseboard is low to the ground and easier to control.
Carefully protecting surfaces not being painted is important when spraying indoors, but masking is fast and easy with the right tools.
Prepping Baseboard for Paint
Unless the base trim you're painting is brand new and recently installed, the surface should always be cleaned and sanded before painting.
Clean baseboard with a cleaning agent that also de-glosses at the same time. Dulling the gloss of existing paint helps the new paint stick better to the surface for maximum adhesion. A good product for this purpose is Krud Kutter Gloss Off, or their TSP (tri sodium phosphate) substitute in the spray bottle.
After cleaning and de-glossing, scuff sand the surface with sandpaper, or a sanding sponge. When I sand, I wrap sandpaper around a sanding sponge. The rectangular shape of a sanding sponge makes it easier to sand.
Calk cracks in the baseboard with paintable caulk. I use the Quick Dry caulk from Sherwin Williams.
Sometimes the edge where base trim meets the wall isn't caulked, or the old caulk has separated. If your baseboard includes quarter round, caulk the crack between the two.
For filling nail holes, dabbing a little Easy Sand joint compound over the holes (powder form, not pre-mixed) works well, or Crawford's painter's putty (orange can).
Large gashes, or chips in the wood, are best repaired with a fast drying, durable wood filler that dries hard with low shrinkage. I use Bondo wood filler for this purpose. The filler smells bad, but dries fast and hard without shrinking.
Prepping Stained Oak Baseboard for Paint
Stained oak baseboard involves a couple extra steps before painting. The surface is porous and usually coated with a protective clear coat that needs a little paint preparation. These extra steps don't apply to pre-primed trim (white) from the store, or trim that's already painted.
The tiny pores and holes in oak show through paint if the surface isn't filled before spraying primer and paint. After cleaning and sanding, apply a wood grain filler to fill the deep cracks and pores in the wood. Aqua Coat wood grain filler works good for this purpose. Wood grain filler won't totally remove the oak pattern, but it will level out the holes in the wood so they're no longer visible when painted.
Unpainted oak baseboard should always be primed with a solvent primer. Oil primer works really well, or a shellac primer. The primer I use the most for priming unpainted wood (trim and cabinets) is Zinsser BIN.
Priming Baseboard for Paint
Unless your baseboards are unpainted, or painted, but in really bad condition (water stains, bleed-through from wood tannin), primer isn't needed if you use high quality paint.
Pre-primed baseboard from home improvement stores can be spray painted without the need of a separate prime coat. Two coats of paint provide the best looking finish.
The Best Paint for Baseboards
I've used many different paints over the years for interior trim, but my two favorites are Pro Classic acrylic and Emerald urethane, both from Sherwin Williams. I've sprayed Pro Classic on trim and doors throughout my painting career, but now I mostly use Emerald urethane because the paint is a little more durable than Pro Classic. Both products level really nice when sprayed for a super smooth finish.
There are many excellent paints on the market for trim, including Benjamin Moore and PPG. Sherwin Williams is what I've used the most over the years and it's the paint that I'm the most familiar with. The paint you choose for your interior trim should be one that's durable and meant for use on trim. Don't paint your base trim with cheap wall paint. The paint won't dry hard enough for durability.
Masking and Spray Painting Baseboards
Masking baseboard for spray painting is one of the easiest parts of a room to mask, but you need to use the right tool. The best tool for masking off floors below baseboard is the 3M hand masker tool. As a painter, I use this tool almost on a daily basis. This awesome tool saves a ton of time when masking floors, walls, and windows for spraying.
Move furniture out of the room, if possible, or move it to the middle of the room and cover everything with plastic.
The best painter's tape to use is green Frog tape. This tape has almost completely replaced the blue painter's tape I've used for many years. Frog tape is more expensive, but I rarely get paint bleed-through when I use it. Use painter's masking paper and green Frog tape to cover the floor below.
You can use a smaller cup sprayer (HVLP), but an airless sprayer is best if you have a lot of trim to spray. With an airless sprayer, you can siphon paint directly from the container instead of having to refill a cup constantly. Another issue with an HVLP sprayer is that the paint must be thinned to the right viscosity, or the spray gun will clog.
You can rent a quality sprayer from a paint store, or a home improvement store. Brands to look for are Graco, or Titan. I have a Graco 495 airless sprayer that I use for everything, interior and exterior spraying.
I really like the green spray tips by Graco. These are the FFLP fine finishing tips, which work great for spraying trim. The two best spray tip sizes, when using the green Graco tips, are either 210, or 310, depending on the width of your baseboard. The 210 tip produces a 4-inch spray fan and the 310 produces a 6-inch fan. If you use the Graco FFLP tips then you must also pair that with their blue RAC X tip guard.
Spray the baseboard in one direction, starting from side to the other. Don't start, or stop, in the middle. Hold the spray gun about 12-inches from the surface when spraying and move at a steady pace to prevent paint runs. Apply two solid coats for a smooth, uniform finish.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
I used the Bondo spot putty and wanted to see what you prime it with? I sprayed a primer and 2 coats of the solo from Sherwin Williams and you can see the red glaze. Also in some of the area where the Bondo is the paint runs.
I've never used Bondo putty or Solo, but I use Bondo wood filler a lot to repair cabinets I'm painting. I prime the wood filler with either BIN shellac primer, or oil-based primer, followed by Emerald urethane enamel. I've never had a problem with the filler showing through. You didn't mention what type of primer was used (latex/oil). If latex primer was used that could be the problem. Try spot priming the putty with oil-based primer and repaint.
© 2019 Matt G.