Painting MDF and popular

[Larry Dublin]

I built a small cabinet of popular and MDF. Primed with Zinzer 1-2-3 Primer (brushed and rolled) and painted (sprayed) with Valspar latex. Coating looks great but after one week everything is still "tacky."

How long should this take to dry? What did I do wrong?

Thanks,

Larry

[Roy Hatch]

Larry, Valspar latex should be dry within hours at the most - should never take a week. If the reaction is with the MDF as well as the poplar, then it's not the wood. Suggestion - try spraying some of the latex without the primer and see if it will dry properly. If it does, then perhaps you have a compatibility problem. Is the latex very old or has it been subjected to freezing?

If your cabinet won't dry, I have no suggestion other than remove the paint and start over. If you're lucky someone may have a better solution.

Roy

P.S. It never hurts to test your finish on something other than your project.

[Greg Funk]

All of our interior doors were poplar with MDF panels. They were painted with an oil based primer and then a couple coats of acrylic latex. We tried latex sealers and I didn't like it. The latex sealer was more difficult to sand. I don't know anything about Zinsser 123 but it doesn't appear to be oil-based. Not sure what to suggest other than waiting to see if things harden up and if not then redoing with a different combination.

In general I found the water-based sealers raised the grain far more than oil-based and I couldn't get them as smooth as the oil-based versions.

Greg

[Larry Dublin]

Thanks for the replies.

Roy - the reaction was more with the MDF than the poplar. Primer and paint were fresh "off the shelf" from a new Lowes. Scraping down and recoating seems to be working.

Greg - I agree with your observations. I never thought about using oil based primer. Figured water based over water based. Just did a mantle and fire place surround out of MDF and did not have these problems. The water based stuff did raise the grain and sanding was a pain.

Humidity has been really high lately and that may have added to the problem.