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I "restored" a bathroom that had had a heavy wall paper that did not come off neatly. I repaired the walls and ceiling and skim coated much of the wall. I also sanded and repainted a shower ceiling. I found numerous recommendations for Zinsser BIN primer and rolled that over all of the prep'ed areas. There were one or two coats on the primer, depending on initial coverage. The primer was allow to dry at least a day. The walls and ceilings were then painted with at least two coats of normal household wall paints.

Three months afterwards, the shower ceiling started cracking and pealing. A year or so later other areas started to do the same. From the chips, it looks its the primer that pealed away, not the paint from the primer.

So, I now have to redo the entire bathroom.

Did I get a bad batch of primer?

Is there a better product to use?



Even in areas that from a distance look good, a closeup reveals that the cracks are everywhere.

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And an unrelated question ;-) all of the pictures got rotated 90 degrees when I uploaded them. Is that normal here?

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  • Usually caused by surface contamination, incompatible products, or too heavy/thick application. How did you prepare (e.g.clean/rinse) the original wall surface(s) prior to application of the shellac primer? How many coats of shellac did you apply, and how thick? How long did you wait prior to applying the paint, how many coats did you apply, and how thick? Edit the info into your question. – Jimmy Fix-it Jul 19 '20 at 18:18
  • Updated. Define "how thick". It was rolled on with a 1/4" - 3/8" roller. – Mike Smith - MCT - MVP Jul 19 '20 at 19:15
  • When a paint manufacturer says a paint will cover, for example 400 sq.ft/gal., it means that it should be applied at that rate. When paint is applied in coats that are too thick (or if recommended drying times between coats are not heeded) it can form a film across the top with wet paint beneath. The film starts to cure and stretch/pull with wet paint beneath which can cause cracking and crazing similar to that seen in your pictures. – Jimmy Fix-it Jul 19 '20 at 22:08
  • Are you sure it is separating at the primer, and not the skimcoat? Was the skimcoat allowed to dry thoroughly? How was humidity at the time? – Harper - Reinstate Monica Jul 19 '20 at 23:09
  • Skimcoat was good and dry. One - two days. – Mike Smith - MCT - MVP Jul 20 '20 at 1:13
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When you say redo the entire bathroom does that just mean redo the sections of exposed wall? Because if it doesn't you should consider the opportunity to pull the old drywall entirely, replace it with a modern bathroom wallboard (such as densarmor or similar) and refinish the walls. Sanding and reskimming are messy and laborious, replacing the wallboardb would give you a better result and maybe afford more opportunities along the way.

But let's say you're not going to replace the wallboard.

You should sand them down aggressively. Get a mechanical sander that you can attach a vacuum or dust manager to.

Then you need to seal the walls. Old wallpaper walls are notorious. I recommend you use zinsser gardz for this (you can order it from big orange hardware store). Gardz penetrates and seals any residual wallpaper, adhesives, etc. Two coats will be safe even if not necessary. The second coat goes on fast so be careful of runs.

Then I would use an adhesion primer such as inslx stix (it's a Benjamin Moore product so should be able to find it at those retailers). Urethane primers are really sticky, but follow the directions carefully regarding dry and topcoat times. You may want to scuff sand this primer before topcoating it being very careful to clean all dust from the walls.

Then you can paint a bathroom paint over the urethane primer. Again, follow application and recoat timing instructions carefully.

After it dries and before recoating, vacuuming is your friend. Dust removal is important. It may feel like extra steps but it's nothing compared to your teardown and do-over.

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