Chalky residue on paint job
I recently finished painting the exterior of my new garage. Sort of fancy with lots of trim. The trim was 1x green treated pine, then water-base primed, then two coats of burgundy colored Pittsburgh Paint latex exterior semi-gloss. Most of it done in 35-55 degree temps (the can says 35 degrees for at least 24 hours minimum and I watched that carefully).
Days after drying we had temps around freezing with a little frost here and there. The surface of the paint developed a blotchy chalky resudue. It easily rubs off and looks fine underneath, but seems to return each time there is frost.
I assume the effect will eventually go away, so I can live with it. Maybe I’ll give it a good wipe down in the spring. But I would like to know what’s going on here for future reference. Was it applied too cold? Is it the chemical in the treated wood leeching out? Something else?
The trim was 1x green treated pine, then water-base primed, then two coats of burgundy colored Pittsburgh Paint latex exterior semi-gloss
Someone will probably ask, so that everyone understands what is going on, how long after installing the green treated pine did you paint? It is my understanding you need to leave treated wood by itself for about six weeks to help it dry completely before painting.
I used treated wood before as trim and left it alone for at least that amount of time and have had no ill effect after painting......... years later.
But, I am not sure what would happen if you did paint treated wood too early. I just assumed the paint would not stick and come off. Maybe some else will chime in.
The trim was only on for a week-10 days before painting. Who knows how long at the lumber yard. But I remember it wasn't wet to the touch. I remember reading other threads on this "when to paint green wood" topic and the gist was that you just need to make sure the surface is dry for the sake of adhesion. And adhesion is not my problem here. But I'm open to the notion that I may have not waited long enough. Seems odd though, since I've painted many green treated projects in the past right after the last nail was put in and I've never had this problem before.