Topcoat Releasing


From original questioner:

Sprayed water base stain, let dry 24 hours,applied post catalyzed sanding sealer and let dry 24 hours. Sanded and applied post cat conversion varnish. After several days of curing the topcoat released from the sealer. Any ideas?

From contributor Ro

Need more info. For instance, is the Sanding Sealer and Top Coat from the same manufacturer, and did you add the correct catalyst (# of ounces) to each product?

From contributor Pa


Here's some questions for you;

  • How many hours elapsed between sanding the sealer and topcoating?
  • What grit sandpaper did you use to sand the sealer?
  • Was the sealer sanded well - uniformly dull and smooth?
  • By "releasing" do you mean peeling? Is the topcoat peeling entirely or just is spots?
  • If spots, where?
  • How did you determine the peeling/delamination is between the sealer and topcoat?
  • Any chance of the sealer coat was contaminated with a substance that would block adhesion?
  • How many coats of sealer were applied? How many CV?

From contributor Pa

Which waterbased stain did you use?
I ask because some are not truly waterbased, but more of a hybrid oil stain that can be cleaned up with water.

From contributor ru

The sealer and topcoat are from the same brand. They are designed to work with each other specifically. Sanded with 320 and topcoated within a couple of hours. I know the topcoat released from the sealer because the stain was still sealed good. I could not get through the stain with water, thinner ,etc. It had to be sanded to cut through it. When I say releasing I mean you could get a corner of the topcoat with a razor blade and slice it off easily.

From contributor Ji

What brand and product?

From contributor Da

Based on what you describe you definitely lacked intercoat adhesion. Your topcoat may have set up too quickly to allow itself to wet into the contours of your 320 sandscratch pattern. It may have bridged the ridges of the scratch instead of allowing itself to reside in their contours.

Adding retarder might help along with going with a wider scratch such as 280 grit.

Also to note, if your scuff material was at all dull then instead of creating a nice tooth you were instead burnishing your surface, a recipe for a failed finish, one which will suffer from lack of intercoat adhesion.

Good luck and hope this helps.