Painting - newbie needs help--latex enamel gloss and weather changes

hello, i'm new to these forums, and haven't found an answer to my question doing a search.

i've just painted my fireplace mantel surround out in my back yard (it is under cover), and it's suddenly gotten cool and rainy.

i'm not sure what to do to protect the mantel so it will cure properly. i was going to let it cure outside for a couple of weeks before bringing it in.

here's the details, if you think you need them to help me:

during the last warm days of the year (60s to 80s F and dry humidity), i decided to take our wooden fireplace mantel surround outside to skim coat and paint it. we don't have an indoor workshop, nor room in our house for painting.

i designed and built the mantel myself several years ago out of furniture grade plywood, laminated wood corbels, and various pieces of wood molding and quality trim. it has hung on our living room wall with only a primer coat all this time, waiting until i had time to finish it.

i'm using a large screen house/tent as my backyard workshop--it has good ventilation and provides protection from falling and blown debris--and a cover against rain. the mantel is laying flat on top of a picnic table inside the screen house.

on monday i skim coated it with dap premix joint compound (outdoor temps were 80 F) and let it dry overnight. i did this to hide the laminations and give the mantel a plaster-like finish.

yesterday morning i sanded down the joint compound, cleaned the whole thing up with a damp cloth to remove all the dust, then applied a high-quality latex enamel undercoat.

a few hours later, the undercoat was very dry and the weather was still good--mid-60s and breezy and dry--so i put on a coat of behr interior/exterior high-gloss latex enamel.

by the time i finished the first coat of paint, it was starting to get dark. but temps were still around 60 degrees, and forecast to drop to 48 overnight. all well and good.

my plan was to leave the mantel outside in the screen house for a couple of weeks, while the weather is still fall-like, then bring it inside and let it finish curing while hanging on the living room wall.

this morning it is raining hard! i went out to the screen house and the temperature is in the low 50s and dropping. the RH is in the 60-70 percent range. it will probably freeze tonight and may even snow. then the forecast is for it to warm up again, into the 50s and 60s.

right now the paint on the mantel looks good! the rain doesn't seem to be able to get to it through the screen (it is a big screen house). but i am concerned that such a severe weather change so soon after applying the paint is going to compromise the curing.

should i bring the mantel inside to cure now? will it hurt it to cure in these colder temperatures?

i had hoped to get a second coat on it this weekend, but i can always wait until next summer if that doesn't seem like a good idea.

thanks!!

Welcome to the forums Alice!

I can't speak for the weather in your locale but I've painted new homes here in cold weather. As long as the substrate was warm before application and the temps stayed above freezing for several hours after drying - I've never noticed any issues. It wouldn't hurt to cover up the mantel to help it retain what little heat it has so you can apply your 2nd coat of enamel this weekend.

thank you very much, mark. that is a relief.

how long do you think i should allow the mantel to cure before washing/handling it under these conditions?

40s-50s during the day, 20s-30s at night.

alice

I wouldn't think there would be any reason to wash it before it's reinstalled :confused:

After 24 hrs the paint should be dry enough to bring it in. It won't be bullet proof but a little care and common sense goes a long way ;)

well, actually, once we bring it into the house, there will be causes to wash it. we have a slobbery dog. that's the main reason i'm using high gloss enamel paint.

i want it to cure away from the dog, and the best place for that is the screen house.

so under these outdoor weather conditions, how long do you think it will take this paint to cure?

thanks!

btw, it didn't freeze last night, so maybe the weather will be moderate for another week or so.

Cool and damp conditions always slow down the paint's curing time. Latex paints can take a few weeks to cure under normal conditions. I don't know how long it would take to cure on your porch. If you can keep your dog away from the mantle piece for a couple of days once you bring it inside, I'm sure it will be fine. Before paint cures but after it dries - you can still wash it lightly, you just can't scrub it with detergents.