I put the final skim coat of 90-minute hot mud on the walls this afternoon, how long should I wait before priming? I've seen everything from overnight to 3 days, and the manufacturer's website doesn't have a number.

Using Sheetrock Brand Easy Sand Lightweight Setting-Type Joint Compound: http://www.usg.com/sheetrock-easy-sand-lightweight-setting-type-joint-compound.html

Going to use Zinsser 1-2-3 primer if that helps at all.

  • Setting type compound is usually only used for the base coat. Whipped GP compound for finish coats. Setting compound tends to have a lot of air pock and is hard to sand to a smooth finish. Hope your's comes out good. Apr 21, 2013 at 7:43

3 Answers 3


I usually give it a full day to dry. In general drywall type compounds turn to a lighter color when they dry so you can gauge from that if it is too soon to paint over.


It depends on thickness, temperature and humidity. Most of the time, overnight is sufficient. Latex primers are more forgiving of any subsurface moisture.

I have a moisture content meter I use after water damage repairs. Interior MC should be under 15%, exterior under 25%.

You would want a full dry before sealing with a shellac or oil based primer. Blistering would be the likely result otherwise.


I always wait for a FULL 24 hours for a light skim coat, provided the humidity is low and the fans have been running in the room non-stop. For freshly-mudded joints or thicker coats of joint compound, you'll need at least a week of low-humidity dry time and good air flow in the room. If there's still moisture in the wall, the paint will peel off in sheets.

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