Originally Posted by Jay1
If you use a water/woodglue mix to seal up the exterior of the box (sand smooth), then prime and paint with an outdoor type paint, it should hold up well to various abuse.
Originally Posted by Audiophile34
Pretty much any paint will do. Especially on mdf which is super smooth to begin with.
I used walmart brand cheap paint on my faces of my sub build.
This thread pains my eyes to read!
Coatings are not remotely considered equal, and shouldn't be suggested as such. For a group of people so meticulous about ensuring a flat frequency response, I find it ironic how often a build is finished with such inadequate coatings.
I am going to try to simplify sub boxes as basically furniture for the sake of this conversation. The #1 recommended finish if I were to sell to a furniture manufacturer would be a conversion varnish. They exhibit great moisture resistance, short recoat time, stain/chemical resistant, gloss retention. Downfall is they can be temperamental to environmental conditions when applying, thin dry film thickness (not good for filling voids), and smell like the devil. My choice Sherwin Williams Sherwood Conversion Varnish
My next vote would be a precatalyzed lacquer. These are typically approved for KCMA specs for moisture resistance, stain resistance, chemical resistance. Short recoat time, fair gloss and color retention, easily sandable, and imo user friendly. I say they are user friendly because any mistakes you make can be sanded away in seconds (think sanding drywall mud). Downfall is they require spraying, smell like hell (however not as bad as conversion varnish), thin dry film thickness (not good for filling voids). My choice is Gemini Precat Lacquers
In this case I may suggest an epoxy as well. And when I say epoxy I don't mean that Nancy boy waterborne epoxy. Sure it has it's place in the coatings industry, but furniture typically isn't one of them. If you're going with an epoxy I want a two part solvent borne epoxy that shows excellent moisture resistance. Call a local paint store for their specific branded recommendation if you want to go this route (and no Lowe's and HD don't count as paint stores) Positives:great moisture resistance, chemical resistance, mar resistance. Downfalls: two components mean more $, not as easily sandable, dry time mediocre typically, ideally needs sprayed, and also smells like death. My choice for pigmented epoxies PPG Amercoat, Sherwin Williams Macropoxy 646, or save your money! There are 2 part "bar top pourable" epoxies as audiophile mentioned which could also be an option depending on your set up.
My next vote good old polyurethane. I don't love it, I don't hate it. Does it work, yes. Does it work perfectly, no. Is it incredibly versatile absolutely. Positives:brush, roll, spray application. Good abrasion resistance, fair moisture and chemical resistance, priced just right. Negatives: Slow dry time, slow recoat time, mediocre sanding, propensity to yellow, mediocre gloss retention. My choice:Minwax Fast Drying Polyurethane.
If you can spray use the Gemini system. If not hit with an alkyd based primer or paint, and top coat with polyurethane.
Notice I recommended no waterborne finishes. Let your wife use those. They have their place and are incredibly revolutionary in the industry, but not for furniture!