To seal or not to seal? To prime or not to prime? These are the questions that can definitely try painters’ souls (not to invoke Shakespeare and Thomas Paine too much—but their quotes are actually appropriate!). And I’m asked these very questions on a daily basis, from both Pros and DIY finishers alike—and, as such, it is a topic that requires focus for all of us who are involved in the art of finishing. So when should you use fine wood sealer or primer?
In the eyes of paint and coatings manufacturers, a fine wood sealer and primer basically perform the same function but do so with a different visual end result—i.e., they penetrate the wood fibers and create a clear or pigmented film formation for the top coat to build upon.
Wood Sealers for Fine Wood Finishing
Common types of wood sealers are clear, translucent and pigmented. Wood sealers used in fine wood finishing, are, on average, clear in their dried/cured film formation and allow the underlying color of the wood, be it natural or a pre-applied wood stain, to show through. Examples of the clear wood sealers in the EMTECH line are the EM1000 Universal Sanding Sealer and the USH3000 UltraSeal-WB Shellac.
Some wood sealers are tinted to offer a wide array of colors, these are produced for the DIY market as “One-Step Seal/Paint” finishes—they are quick “one trick pony” type formulas—but offer limited performance values. Also, there are pigmented wood sealers that are designed for exterior wood surfaces such as architectural wood siding or on exterior decks. In the Target Coatings lab we stay focused on high performance, visually clear, fine wood sealers. The accompanying video will give you a more detailed explanation.
Wood Primers & Surfacers for Fine Wood Finishing
On the other side of the formulating spectrum are wood primers. In our case we focus on the HSF5000 Primer/Surfacer/Grain Filler. Primer/Surfacer products are offered in translucent or pigmented color formats and are used as grain filling and grain locking media to ensure that the wood grain image, be it MDF, birch, poplar or maple, does not “print” back through and become visible in the upper layers of the painted surface. The term “printing” refers to the grain revealing its texture—not its visible color—back through the pigmented or clear top coat that is applied over the base layer. Again, take a look at the video above to learn more about the HSF5000 Primer/Surfacer.
So, depending on what the wood species is you are working with, and the final function that the constructed piece is meant to perform, the selection of the right fine wood sealer or primer can make your finishing schedule a faster, dare I say, smoother, experience.
As always, please feel free to contact my office if you have any questions regarding this topic and the products discussed herein.