Painting large MDF bookcase/shelving system with latex
I am finishing a large, still unassembled custom-made bookcase (16x9feet, 100+shelves) made of MDF. My idea is to have a smooth semi-gloss finish that is resistant enough to hold books without paint peeling/sticking. I prefer to finish it while it’s still unassembled. Since I have a number of time/space constraints, I decided to go for latex enamel from Duron, even though I am aware oil-based would have been probably better. I have done and plan to do the following, which may have included some mistakes – I wonder whether my plan was/is appropriate
A) I used Duron acrylic undercoater to prime. Since rolling the primer left roughness, I decided to thin the primer with water (following but perhaps exceeding a tiny little bit the manufacturer’s recommendation) and applying it with a rug. I put a very fine coat of primer (kind of a “wash” of primer, with the MDF color still visible underneath. Hopefully I won’t get adhesion problems.
B) I got Duron “Plastic Kote” acrylic enamel, semi-gloss, ultra-white. Only after buying the non-returnable paint did I read that the product is “suitable for cabinets and shelving, but alkyd paint or Duron “Signature Select” generally perform better.” So I guess my choice was good but not the best. I have already applied 2 coats of the Plastic Kote paint (which looks very good), and I am not planning to mix products and apply subsequent coats of a different product (unless strongly suggested). I am sanding between coats to get a smooth finish, up to 220 grit (final coat will be sanded to 320 grit). I apply the paint with a brush and 1/4” nap roll.
C) As I said, I have applied 2 coats of white paint. I will apply a third coat with a little bit of latex extender, as to make it more fluid and as smooth as possible. Some shelves and some edges will be painted in pastel colors. (I am going to tint the white paint with either a bit of acrylic artist paint or a bit of dry pigment).
My questions are:
1) Although it’s too late to change now, was it OK to use water-based products for a shelving system/bookcase? It’s not going to be a heavily-used piece (it’s not like kitchen cabinets), and the shelves will not be adjusted that frequently. However, I have heard that professionals strongly suggest using oil-based paint.
2) As I said I am planning 3 coats. I am planning to sand a bit between coats and at the end to have a very smooth surface. Is that OK?
3) In order to make the semi-gloss latex enamel more like a lacquery oil-based enamel paint, would it be a good idea to mix some high-gloss latex based enamel (that does look and feel like a lacquery paint) with the third coat of my semi-gloss paint?
4) I know that latex paint “sticks”. I have been testing the paint by placing heavy books in a painted shelf ‘sample” that has all the coats of paint. So far, they don’t stick. However, in order to add protection to it, and avoid “stickiness”, would it be a good idea to also put some water-based POLYurethane?? I have heard that there could be problems in the poly chips – a future touch-up would be much more difficult. Therefore, and in order not to add too much thickness, I was panning to add just one very thin coat, applied with a rag, just to “seal” the open pores of the paint. Would that be OK?
5) It’s going to be hard to paint the borders of each shelves with pastel colors without staining some of the white-painted parts of the shelf. Putting masking tape may be too time-consuming. I am planning to again use the latex extender to allow for a quick clean up of colored paint on the white paint. Is that OK?
Thanks.
Carlos
You can use just about anything over latex....
Quote:
Originally Posted by Carlos Arteta
Jim,
Thank you very much for your reply.
Would it be then a good idea to put some water-based polyurethane over the semi-gloss latex, for added protection? If so, how long should I wait before applying the poly? Thanks again.
Carlos
....but you shoulda used an alkyd primer and finish. Carlos, when I finish MDF, I use joint cement as a filler. I trowel it on using a broad knife and trowel it off clean. It leaves a powdery residue that I sand off with a ROS and 220 paper. One coat of oil primer and two coats of alkyd finish, will make it look like glass. As Becker said, latex will remain tacky, and for years on, your books will tack to the finish. You can use a clear finish over your latex. Wait about a week and recoat. Good luck.
