Home Improvement Expert Danny Lipford

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Can Primer Be Used as the Finish Coat When Painting?

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I am planning to paint my shed. Could I use some leftover primer as the exterior finish coat? -Aaron

Hi Aaron,

Primer is not formulated to stand up to the elements and should be topcoated within several weeks to ensure proper bonding. If left uncovered for an extended period of time, primer will tend to deteriorate and chalk, which could prevent future coats of paint from adhering properly.

Also, primer comes with a flat sheen to promote bonding between the substrate and top coat, which does not hold up as well to sun, rain, and dirt as satin or glossy paints.

Good luck with your project,

Danny



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16 Comments on “Can Primer Be Used as the Finish Coat When Painting?”

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  1. Jacky Says:
    December 30th, 2009 at 10:24 pm

    Can a primer be used as the finished coat in a bedroom?

  2. Jacky Says:
    December 30th, 2009 at 10:32 pm

    To be more specific…I painted my room with a primer and then a finished coat. After a few thoughts, I realized that I like the colour of the primer more. Is it possible to repaint the room with the primer over the finished paint?

    Thanks

  3. Official Comment:

    Ben Erickson Says:
    December 31st, 2009 at 12:14 pm

    Hi Jacky,
    While primer should not be used as a finish coat, you could paint a scrap with it, let it dry, take it to a paint store, and have the color and gloss matched to a finish paint.

  4. barbara Says:
    August 25th, 2010 at 9:52 pm

    I stripped my cedar siding to bare wood and then put a coat of oil based primer on it. That was 3 months ago. We have had hot, dry weather since then. What do I need to do to prepare it for painting in the next couple of weeks?

  5. Official Comment:

    Ben Erickson Says:
    August 26th, 2010 at 10:03 am

    Hi Barbara,
    Since some outside primers can degrade over time if not painted promptly, read the label carefully (or contact the company that made it) to see if they indicate a time period during which the primer should be topcoated. If your primer has been on longer than that, you might need to apply another coat of primer before topcoating. Good luck with your project.

  6. Sara Says:
    October 25th, 2010 at 11:56 pm

    Hello,
    My boyfriend has just painted the bedroom with primer. I am trying to talk him into putting a finish coat over the top, but I don’t have any solids reasons to give him as to why that needs to be done. So I’m hoping for a good explanation of why primer cannot be used as a finish coat. Also, primer was applied to the interior of the downstairs about a year ago. Do we need to prime again, or can we put a finish coat of paint over that?

  7. Official Comment:

    Ben Erickson Says:
    October 26th, 2010 at 11:00 am

    Hi Sara,
    Primer is not formulated to be used as the final topcoat, that includes both inside and out. When left uncoated inside, primer will not clean up well when it gets dirty, will have a no sheen, and isn’t available in a range of colors and sheens. As far as covering over year old primer, it would not be as big a consideration inside as out, where the primer would have degraded over time due to exposure to the elements. If your year old interior primer is in good shape and isn’t dirty or stained, you can probably topcoat over it, though it wouldn’t hurt to prime it again. In the future you might want to consider some of the new paints that combine a primer and topcoat in one such as Behr Premium Plus Ultra, which we did a Best New Product segment on. Good luck with your project!

  8. Jennifer Says:
    November 13th, 2010 at 4:21 pm

    Exterior latex primer that was applied to our home a few weeks ago is turning yellow. Will the yellowing get worse over time if the topcoat isn’t applied? Other than the yellowing, what other problems can occur if this primer is left uncoated? It may be a while before we can apply the topcoat since the weather is now too cold to paint.

  9. Official Comment:

    Ben Erickson Says:
    November 13th, 2010 at 6:39 pm

    Hi Jennifer,
    As Danny’s article above says, primer that is not topcoated over within a few weeks can chalk and degrade over time, resulting in possible failure to adhere properly to the topcoat when it is applied.

  10. Dane Brewer Says:
    October 11th, 2011 at 8:12 am

    I am preparing to paint a block wall that has old white paint on it,that is weathered a lot. Do I need to use a primer and if so what kind. This wall is 5ft high and sees a lot of sun and rain
    Thanks
    Dane

  11. Arline Says:
    October 13th, 2011 at 10:45 pm

    Hi,
    I am repainting our dining table and chairs to a lighter color.I already applied a coat of primer, however,it looks very thin to me,is it OK to apply another coat of primer?Thanks

  12. Charlie Says:
    November 2nd, 2011 at 10:00 am

    We replaced the T-11 siding (fir) on one side of our house in early June. We started applying oil-based primer but it got so hot that the primer was the consistency of glue. We tried some additives to thin it out and, over the course of the summer, we got most of the surface covered when weather permitted. (We also had a lot of rain this summer, besides being extrememly hot.) We still have some small areas to cover around where the electric lines, telephone, etc. come into the house – plus some of the grooves in the T-11.

    We looked at the can last night and now we see that we should’ve applied the top coats within 30 days of applying the primer! After reading your advice to Aaron, we understand why but we’re not sure how to proceed from here. Should we go ahead and apply the primer to the remaining raw wood before winter or are we wasting our time and the primer? Will we need to remove and reapply the primer next year before we apply the latex paint we plan to use for the siding? What is your advice? Thanks!

  13. Louis Says:
    August 18th, 2012 at 2:52 pm

    20 years ago my dad used Benjamin Moore’s exterior latex primer on the stucco walls of my house without using any topcoat. Still looks good and has held up amazingly well. I guess the primer alone might look a bit chalky and the brushmarks show more, and is not quite as abrasion resistant as a paint finish, but on rough stucco surface you can’t really see it and the stucco area starts at the 2nd story where nothing touches it or rubs against it anyway.

  14. Chaston Says:
    August 1st, 2013 at 5:54 pm

    Hi i have built some fenders out of wood for my trailer. I didn’t realize i was not putting primer first instead i was putting the actual exterior paint the last coat i put on was the primer/sealer. I am going to put a coat of regular exterior paint on top but underneath is it OK if i just leave it like it it with just the regular exterior white paint?

  15. Char Knipper Says:
    August 13th, 2013 at 7:47 pm

    I have a pressed wood bathroom cabinet that needs painted.Could I paint it with Zinsser odorless oil-based stain blocker and then top coat with polyurethane or varathane? Thak you1d

  16. Official Comment:

    Ben Erickson Says:
    August 26th, 2013 at 4:29 pm

    Hi Char,
    Your question about how to paint a particle board bathroom cabinet was answered in the rapid fire segment in the first hour of our radio show. You can listen to the show on our website at http://www.todayshomeowner.com/radio/2013/08/24/todays-homeowner-radio-show-for-august-24-2013/
    Thank you for your interest!

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