Home Paint and plaster.

[Ryan]

Hopefully someone can help me out. The plaster on my window keeps blistering. It is absorbing moisture and the metal frame underneath is rusting and expanding. Not sure if it is getting moisture through the surface or from behind the wall somehow. This is a picture of a few months after I scraped out the old plaster. Used some rust kill on the frame then re-plastered and painted it. It is starting to blister again. Wondering if the paint has something to do with it. Would a semi or full gloss keep it more moisture out? Would Killz help. Live in Hawaii so its a bit humid and the window stays open all the time. Would appreciate some advice. The blister is actually vertical not horizontal. Cant get the pic to rotate.

 

[TRICKSIXPA]

How long did you let the paster cure before the new paint? Did you use primer sealer specific for plaster prior to painting?

 

[Ryan]

Not sure how long I let it dry.....think I let it dry overnight. The paint was a paint with primer in it.

 

[TRICKSIXPA]

Plaster is sensitive when it comes to paint. I had an old house in Philadelphia all the rooms were plaster. The best thing I would recommend is getting some good paint from a Sherman Williams store. Use a decent primer and a semi gloss on top. Let the plaster dry completely before any paint.

 

[psycho6cyl]

I manage an apartment building in the city and plastering is just like.doing bondo on a car. Prep is key. Use name brand,I prefer benjamin moore and def have one primer one paint. Does any one live above you? Possible leak or ac condensation? Also.make sure you scrape it and let it dry best you can with the humidity. And as stated make sure its complety dry.

 

[Ryan]

How long should I let the plaster dry? What should I do with it now? Sand it down smooth....re-skim it or do I have to dig out all the plaster I put on?

 

[Ryan]

What if I used exterior paint? Is that bad?

 

[John Larkin]

If you can, remove the plaster and sand the metal frame as smooth as possible. Plaster absorbs moisture and the cycle will never end. You need to treat the metal frame with a rust preventer like Ospho, then coat it with a thick enamel primer that will build thickness to fill the pits. An automotive primer like DP40 would be good but it's expensive. It needs to be oil-based. Maybe a few coats of Kilz would work also. Then you should top coat it with enamel paint. You can get some flattening agent if you don't want it shiny. Paint store will have it.

 

[Ryan]

Thanks..... how long should I let the plaster dry? Will the gloss prevent moisture better than a semi or flat?