Primers have a wide variety of time frames for topcoating. If you are using a stainblocking primers, it is usually within one hour for the least. If you are using a slow dry oil, it could be as much as 24 hours before topcoating. Latex primers can usually be painted in four hours of less. Each primer will tell you on the can the drying time and recoat preference. It is best not to wait longer than 21 days to topcoat. Once primer is dry, sanding is usually not recommended because it breaks down the primer, especially if it is a stain blocking primer.

As for the number of coats of primer, one is sufficient, and use two coats of a topcoat, unless it is a very deep color that you are painting. You can also make your job easier by having the primer tinted to 1/4 to 1/2 formula of your final color. In the case of really deep colors, use a deep tint primer that is specifically made for the application. If you are painting topcoat of oil based finish or a gloss latex finish, you need to recoat within 48 hours. If you wait too long (ex: one week or more) the product will begin the cure process and the second coat may not adhere.

If you leave the primer on too long, be sure to wash or vacuum the walls before painting, as dust will settle and could mess up the paint job.

Thank you everyone for this information that I am saving.

I've never heard of a maximum time for topcoating over primer. I've never had a problem even waiting months, so long as the walls are free of grease, dust and dirt.

The walls in the main hall of our home were repaired and primed in March 07 by the previous owners. (they offered to paint but having seen their other color choices, we declined...)

We had planned on topcoating right away but more pressing issues came up (i.e., we had a bathroom problem, then realized we needed to do more work on the woodwork, then we had another baby...), and I just got to the topcoating last week. Paint seems to be adhering just fine. I did, however, scuff the primer with 220 grit before painting.

I oil primed my 28-year-old lattice-topped cedar fence, but rain is keeping me from putting a latex topcoat on it (also because I'm priming both sides and it's a long fence and I want to topcoat all at once). Part of the fence was primed 17 days ago and I can see not getting that first topcoat until at least 20 days has passed. The weather has been very moderate and this may be in my favor. I was told by someone that the primer cures over time and too much time--beyond the recommended 14 days--simply makes the primer "unfriendly" to a topcoat. I don't want to re-prime those areas, but.... Anyone really experience with such a situation? Thanks.

Hi,

If you use an oil primer and have it tinted dark, you will need to add some Japan Dryer into it for it to dry at all. Green and black colorants are the worst. I have run into this feature many times, because both dark green and black doors/shutters are popular in my area.

Casey