I’m having trouble painting a replacement exterior door and casing on my house near Tucson, Ariz. The acrylic latex paint I’m using (Sherwin-Williams Emerald Exterior) dries almost as fast as I apply it with a brush. When I run the brush over a long piece of trim to even the brush strokes, the paint drags, leaving deep brush marks that don’t level out.

I’m working within the manufacturer’s temperature range for the paint and the area is in shade. I’m concerned about thinning the paint as the instructions don’t address this. How can I increase the working time? I’ve used the same paint in New England without any problems.

— Mike Guertin; East Greenwich, R.I.

Dennis Fiorilli, Director of Product Excellence at Sherwin-Williams, Replies:

If you’re able to paint the replacement door in a garage, shop, or other controlled environment before hanging it, that is the best scenario. You mentioned staying out of direct sun, which is a good idea. I also suggest painting earlier or later in the day, avoiding midday when temps are highest.

Don’t paint hot substrates and store paint and primer in a temperature-controlled area until you’re ready to use it. Avoid over-working the paint, which is likely to accentuate brush strokes. Paints that withstand temperature extremes, like Sherwin-Williams Latitude, will help with workability.

A lack of humidity may be contributing to the drying. We don’t typically recommend thinning our paint, but in extremely dry (desert) conditions you can thin up to 10% with water, or use a latex paint extender, such as M-1 Latex Paint Additive and Extender. Don’t add more than the recommended amounts of water or extender. Adding too much extends drying and curing times and can negatively affect appearance and durability.

From Fine Homebuilding #327

RELATED STORIES

• How To Finish an Exterior Wood Door
• Painting and Refinishing Exterior Doors
• Brush-Painting a Steel Door

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Need help with figuring out what to do if your acrylic latex paint is drying too quickly or have a different question? Get answers you can trust from the experienced pros at FHB. Email your question to [email protected].

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