Primer Over Epoxy:
Taking Forever To Dry

Question:

Thanks for a really great website.

I read your article about repairing rotted wood with LiquidWood and WoodEpox from Abatron. I decided to buy some from Abatron to do repairs on an exterior door. I did some repairs about 2 weeks before I applied the oil-based primer (SuPrime 8) from Pratt and Lambert. I did some repairs about 2 days before applying the primer. I took the door off the hinges and put it on a sawhorse in my house for the last repair and application of the primer since the weather was pretty variable. So the climate conditions were more controlled.

The primer dried within a couple of days on the areas repaired 2 days before. However, on the areas repaired 2 weeks before with the WoodEpox, the primer is still tacky after 5 days (it's slowly drying I think). Abatron says they have not heard of this problem. Before I started this project, I called Abatron to find out if there was a window of time to apply the primer and they said just wait until the WoodEpox is hard. I did sand all of the WoodEpox repairs. Do you know what could be the problem? Thanks for any help.

Debbie B.

Reply:

Debbie:

I have experienced some problems with Abatron's products not hardening fast enough, but I can't recall any problems with primer drying too slowly.

The Abatron kits I have bought came with a can of solvent for thinning their products, and for cleaning up tools. I have found that even a tiny amount of their solvent added to WoodEpox greatly increases the time needed for WoodEpox to harden. Since you said that all of the epoxy was hard, I don't suspect that adding solvent was a problem.

I have had problems with oil-based paints not drying when applied over spots or stains of other chemicals, such as oil, grease, or paint stripper.

My approach to your problem would be to scrape off the tacky primer (a heat gun works wonders) and apply some Zinsser B-I-N primer/sealer to the spot. This is a shellac-based primer and is alcohol-soluble (instead of being soluble in mineral spirits) so it works well at sealing in oil-based stains. Then you can prime and paint the bad spot.

Note that brushes used with BIN sealer can be cleaned up in household ammonia or denatured alcohol, but rubbing alcohol won't work.

Bruce Maki,
Editor