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My indoor walls are concrete. I've painted one room with a water-based paint. Now 12 hours later it's cracking and peeling. I think it's because two thick layers were added without proper drying in-between.

For info, prior to painting only one layer of original paint was on the wall and a primer was applied first and properly dried, so the wall was pretty much clean before the real paint job started.

What do I do now? Do I have to scrape the entire wall prior to paining again, or is there some easier solution? I'm assuming painting it over again will only make it worse.

  • Any time paint is pealing adding a second coat will just make it worse. Cracking many times can be painted over. – Ed Beal Mar 6 '16 at 10:50
  • Some parts have "alligator" cracking, but not down to the substrate. I think those are due to a second layer being applied before the first one was completely dry. So is it worth it trying to just prime and paint over that part? – Tomas Rosenthal Mar 6 '16 at 13:24
  • Where is the paint separating? Between which layers? – Harper Apr 8 '17 at 1:02
  • I couldn't tell. I ended up stripping/scraping almost the entire room and starting over. – Tomas Rosenthal Apr 9 '17 at 9:07
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Not waiting between coats would be the cause, 6 to 8-hours is the usual wait for normal evenly rolled-on coats. But, with top-quality paints like Behr or Valspar I wait a day, because of rare lift-off issues. They take a month after that to cure & solidify. Another cause would be Cold, but you didn't indicate any such situation & if would need to be below 50-degrees.

You can strip it or you can skim-coat it with drywall Joint Compound to then start over with the primer & everything. Don't run your roller dry, just try to even everything out. Paint in floor to ceiling single strips & don't do a "Z", "N", "V" or "W" application pattern. Do 3 strips & then go back over those to smooth & even them out. Typically, only 1-coat is needed unless you're jumping to the other side of the color spectrum.

  • Why the recommendation to avoid those diagonals? – donjuedo Mar 8 '17 at 23:42
  • Those diagonals are very uneven in paint thickness or uniformity and, depending on the paint, can be very difficult to keep a wet edge. They "can" turn out okay, but many of the paint/primer combos today just don't go nearly as far and have a lot of trouble filling in whatever letter you've drawn...from what I've seen. – Iggy Mar 9 '17 at 5:20
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If it's actually cracked up off the surface ( of the primer ).

Wait untill it completely dries, take a stiff broom and remove the cracked paint. After this, take a orbital sander to any areas that are still raised.

If you can apply a thin coat of primer over those damaged areas and over the non damaged areas at the same time, then WAIT for all that to completely dry.

Then paint over that..carefully and let that dry.

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