Choosing paint for shelving
Choosing a paint that will be suitable for bookshelves. April 2, 2002
Question
I have to finish a built-in bookshelf wall unit to match the interior trim color in a client's home. I used poplar and MDF in its construction. After a disaster using acrylic paint several years ago (the customer's books stuck to the shelves), I switched to oil based alkyd paint. No sticking or forever-tacky finish, but it yellows in a year or so if not exposed to sunlight. I would prefer to use the acrylic paint but fear a repeat of my past experience. Has acrylic paint changed any over the past five years to solve the drying problem? Are there any pigmented w.b. lacquer finishes that I can have color matched?
Forum Responses
I have a friend that had the same problem. He ended up putting two coats of polyurethane over the acrylic paint. Worked like a champ. The surface was solid and nothing stuck to it.
From contributor S:
Make sure the color of the trim is made in a flat paint. This will give your first coat of waterborne urethane some adhesion. You can recoat over waterborne urethane within 2 hours and get a chemical bond, but anything longer and you should scuff sand to promote adhesion. Look for a non-yellowing WB urethane. If the bookshelf will be subjected to a lot of abuse, look for a two-component WB urethane. Either product should cure in about 2 weeks after application, so avoid restocking the shelves too quickly.
Lenmar makes a nice two component urethane that has been approved by the MFMA (Maple Floor Manufacturers Assoc). If it will stand up to gym floors, it will pass the test on your project.
From the original questioner:
I hadn't thought of top coating with a clear coat. What kind of cure time should I give the acrylic paint before adding the w. b. finish coat? I have used Oxford Hybrid Super-clear polyurethane before and have enough for this job. Would that fit the bill?
From contributor S:
Has the bookcase been primed? Based on your substrates, it would be best to coat both the MDF and poplar with a shellac based pigmented primer like BIN from Zinsser. Allow the BIN to dry for about 24 hours and make sure you have a lot of fresh air ventilation. You also might want to consider tinting the primer to help in the initial hiding. The topcoat should have a formula, so cut the formula in half and add that to the primer.
Then you can apply the flat latex paint. Two coats over the tinted primer should give you a uniform appearance. Allow the latex paint to dry overnight before topcoating with WB urethane.
Check with Oxford to see if they have a sheen level that will match the sheen level of the existing trim. You do not want to discolor the paint with the urethane. Also, do not use steel wool when working with the WB urethane. Two coats should be sufficient and allow the film to cure for approximately 2 weeks.
Latex paint takes about one month to fully dry. I painted shelves with Pitts Manor Hall interior semi gloss. Waited one month, and then no sticking. You might also want to look at a paint called Breakthrough (waterbase). They claim it is the most durable paint available. A good shop can tint to almost any color. Available in different gloss levels. Spray or work fast with a brush/roller/pad because it dries very fast. A problem with the system of clear coating over paint is that touch-up/repair is difficult. Someone will have to sand through the clear coat, repaint, and then re-clear coat. Better to use a top quality latex or breakthrough.
From the original questioner:
Good point - touch-up would be a problem. I would be clear coating just the shelves so if it were necessary to repair, it might be easier to just refinish the whole shelf. I've used Breakthrough before and I'll look into the possibility of matching its white to Behrs ultra white color.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor K:
I've used Breakthrough many times on interior floors and exterior wooded stairs and it really is extremely tough. Once it's dry, there's no plastic-like stickiness at all and it sands easily, like an alkyd. It smells terrible and dries so fast that it's hard to work with. I would recommend looking into using Floetrol or other additives.
