Good question; but I don’t think a properly prepared and applied paint (even barrier coat) will cause any blistering problems.
Originally Posted by Extemporaneous
1. As everything in this world equalizes, I'm sure there is some effect ...
... 2. I would also think that if the moisture is making it to the interior face or your hull and it's NOT condensation
, your hull must be saturated.
1. Since everything allows some water
vapour to diffuse through it to some degree, the newer term "Vapour Diffusion Retarder" is more accurate than the old “Vapour Barrier” terminology. The ability of a material to retard the diffusion of water
vapour is measured by units known as "perms" or permeability. A perm, at 73.4̊F (23̊C), is a measure of the number of grains of water vapour passing through a square foot of material per hour at a differential vapour pressure equal to one inch of mercury
. Any material with a perm rating of less than 1.0 is considered a vapour retarder.
Some application tips to prevent bubbles & blisters:
Avoid painting in direct sunlight or application to hot surfaces. When any paint is applied to a hot surface the solvents vapourize very quickly. At the same time, the paint is drying, forming a film and becoming resistant to the transfer of the solvent underneath. This creates a bubble. Excessive thinning combined with heat will increase the chances of this condition occurring.
Allow the surface to dry completely before priming and painting. Obviously, moisture underneath the paint film can cause a lack of adhesion.
Allow 4 or more hours of drying before predicted adverse weather
. Exposure of the paint film to rain, dew or high humidity shortly after application, and during the drying phase, can also cause paint blisters.