And yet you still used Bullseye latex? Really? I.......have no response.........You've stupefied the Pacster!

 

I have a front door that I stripped to bare wood, primed with Bullseye Latex, allowed 24 hrs. dry time, and finish coated with a factory tinted, deep-toned latex enamel. All work is was performed when the door was out of direct sunlight and temps were 70's with low humidity. One week later the temps get to the 90's and the door bakes big time in direct sun for most of the day, I get blisters the size of quarters in several spots. I've repeated this but with an oil primer with identical results. The bubbles are to the bare wood and only appear after the door is finish coated, and only after it gets to the 90's, the primer alone exposed to the high heat didn't blister, but as soon as the top coat bites into the primer and it bakes, boom it blisters. Both times the door was stripped to bare wood and final sanding was done with 120 paper. The door is sealed on all edges and the inside is stain and poly. Oh btw, I'm the third contractor who's said they could stop the blistering on this door, ha I couldn't resist that challenge. Any advice or product suggestions would be appreciated here, thanks!

It has nothing to do with the paint brand or primer. It's the heat, you can either put a storm door on with tinted gass. Or you have to pick a lighter color. In other words, a color that will reflect the heat and light versus absorb it. Something white base prob

 

In terms of gasses, pressure is proportional to temperature. Some sort of solvent in the wood, i.e. water, turpentine, etc., is causing the paint to bubble when the temperature rises. Surface contaminates like salt, can draw in moisture through permeable paint films. They are not noticeable once the moisture is condensed. But as the temps rise and the liquid changes state to a gas, the pressure can cause bubbling if it doesn't evaporate through the film structure. .

The question is, how can moisture permeate into the paint film but not escape? It's more than likely the moisture is in the wood already. Have you taken a moisture test?

 

the 3 main causes for blisters are surface contamination, moisture or thermal.
stick a moisture meter on it. primer is more permeable than your topcoat which is probably why its not blistering. that doesnt mean moisture isnt present. I doubt it but a mm will rule it out.the only other idea is that the blisters are thermal which indicates that your top coat is drying too fast, maybe high temps?or multiple coats are being applied too close together trapping moisture in...ive had problems with breakthrough because of this...i tried to rush a finicky product

 

If its an exterior door, the weatherstripping is probably doing too good of a job, unfortunatly!! A dark color door will create a great heat absorber, causing moisture inside the house. This moisture will want to escape via the door and the latex enamel cannot release the vapor fast enough. Best bet, is to use an true oil enamel or paint the door with a flat.

 

I used to see this kind of blistering on a fairly regular basis, but i haven't seen it at all in quite some time. Why? Because i quit working for companies that sell Kilz and Zinsser primers. Coincidence? Maybe. There are lots of reasons why cheap primers fail. But what do you blame? The primer or the substrate? If that door had been primed with a quality long oil alkyd, this wouldn't be happening. So where does the blame lie?

 

He does say that after his first attempt, he sanded the door down again and then applied an oil based primer. Doesn't specify which one.