We bought this door:


I've primed it using Zinsser and then gave it 2 coats of Behr Marquee Exterior.

Looks great. Alas, 24 hours later, I can take my fingernail and scrape of the paint.

It's been a bit humid/rainy. Do I just need to give it more time for the paint to fully harden? Or did I do something wrong with this fiberglass door?


Another day and the problem remains. I can confirm it's the paint. The paint can be scraped off with a fingernail, but the primer stays.

I'll give it another day or so (it's been humid) and hopefully it fully 'cures'. But if not, do I have options short of stripping the entire door? Is there any sort of top-coat I could apply to give it a stronger surface?

  • 1
    Sounds like you did everything right. When you scratch it with your fingernail, is it just the topcoat or both that and the primer that are falling off? If it's primer as well, I might theorize that the primer bonded poorly due to dust/contamination/etc. Jun 2, 2015 at 1:09
  • @AloysiusDefenestrate I can confirm that it's just the paint...the primer is adhering fine.
    – DA01
    Jun 2, 2015 at 18:09
  • 1
    Having just experienced a bad batch of caulk (wouldn't set!), my only guess is bad paint. Maybe this needs a bounty to attract some attention from real paint experts. Jun 3, 2015 at 0:55
  • I can honestly say I've had no end of problems with Zinsser products. But that's a different story. I hope you find a suitable paint that holds fast.
    – hookenz
    Jun 4, 2015 at 23:10
  • @FreeMan I don't know. We sold that place and built a new house. :)
    – DA01
    Jul 29, 2020 at 22:07

4 Answers 4


I have lots of questions!

  • Is the door installed in place? If so, is there a storm or screen door?
  • Did you paint both inside and outside surfaces? If so: Did you use the same paint on both? Are they both experiencing the same problems?

If there is a glass storm/screen door in front of the door, this could lead to problems with paint on the outside where the paint is trapped between the door and the glass. If you could answer these questions in your question or as a comment, I can provide a more targeted response.

This paint has a 4 week cure time and should will take longer to set if applied in higher than 60-70% humidity.

For expert advice, you may consult with a BEHR Certified Coatings Professional, call 1-800-854-0133 Ext. 2 in the US.

  • "This paint has a 4 week cure" = wow! That could be the issue. We took the storm door off when we installed the door and replaced with a plain screen door, so that's not the issue. We did paint both sides. The inside is a different paint, but does seem a bit 'harder' than the exterior paint.
    – DA01
    Jun 4, 2015 at 16:36
  • Yeah - if the paint dried (no longer wet or tacky) but was easily damaged by scratching it, this could be a time to cure issue. I'd expect a harder film before the 48th day, but perhaps not the same week it was painted.
    – Ben
    Jun 4, 2015 at 21:56
  • The Questions should have been asked in the comments in the OP. The last paragraph sure feels like spam...
    – FreeMan
    Oct 17, 2023 at 13:15

I am a painting contractor. Do not try to scrape anything off with your fingernail until it is fully cured. This is something all the wannabe or new painting contractors run into...and they are so naive they want to blame somebody before the paint is even cured.


Paint pealing off is usually a sign that you have layered an oil based paint over a water based paint or primer. A good sign that this has happened is if it peels of in strips.

Your paint may also have gone bad before you bought it, if it was not properly stored for instance, it may alternatively have been mixed with the wrong dyes (using an oil based dye on water based paints can do this), and various other reasons. If the paint is chalky, or just scrapes off than this may be the case.

You can strengthen a a layer of bad paint by using a peel stop and strengthening product such as Zinsser Peel Stop. This may solve your problem.


I have had bad luck with painting fiberglass doors with latex based paint. The problem is it doesn't bond well to smooth impermeable surfaces and it's tendency to stretch like a balloon is a bad combination. I have had good luck with oil based paints that adhere well and dry much harder. I know that some manufacturers say that oil based paints will damage the fiberglass layer, but I have not found that to be the case.

  • 1
    I would imagine that proper preparation, including the proper primers would allow your latex paint to work just fine on a fiberglass door.
    – FreeMan
    Oct 16, 2023 at 23:29

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