I want to cover oil base paint with acrilyc latex paint in the bathroom. Am I going to run into any problems with the paint adhering?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
By considering things like energy-efficient mechanicals, window orientation, and renewable energy sources, homes can be evaluated to meet the energy codes. Here's what the IRC has to say.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Use a good adhesive primer first and you won't have a problem. I've been told that latex paints won't stick to oil based finishes unless you prime first.
I was told the same thing until the other day when my Sherwin Williams rep told me latex will cover oil but oil won't caver latex. He said it's because oil will not expand with the latex under it but latex will expand over the oil. I don't see how things change but I like primer myself first.
Headstong, I'll take on anyone!
The oil latex thing is as post 3. Think of oil as hard layer, latex as soft layer. You can put soft over hard, but but a hard brittle layer over a softer squishy layer, and when the bottom moves, the top splits. The primer isn't mandatory. The issue being resolved is that oils dry without a lot of tooth on the surface - nice and smooth. More so the higher the sheen. So you do need to do something to remedy that to achieve a satisfactory bond. The two options are sanding to give it tooth, or in a situation where sanding (the better option) is impractical - like repainting the trim in an entire house, you can get a bonding type primer made to grip. Even at that, wiping the oil with a deglosser before priming I consider fairly important. A deglosser is just a gallon of other solvents mixed up and marked up with a nice name to it. You can use lacquer thinner and achieve the same thing. I wouldn't go as hot as acetone or MEK.
"If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain
IMHO I'd sand everything first to get some 'bite' and to get rid of the sheen. Then use Benny Moore's "Fresh Start" - an acrylic primer, but I think even an alkyd (oil) primer would be suitable. Then finish it. I disagree with 3rd poster Jemcon - latex is a good base for alkyd, as I've known for years.
All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
"latex is a good base for alkyd, as I've known for years."
Interior or exterior? Inside, it probably doesn't matter much since heat and humidity remain fairly constant. Outside, there's more expansion and contraction so it might be more of an issue.
Since I rarely use alkyd paints anyway, especially outside (where latex paints that can "breathe" have the advantage), it probably won't affect me much anyway.
When I do use oil-based paints, I try to use an oil-based primer. When I use latex paints, I use whichever primer is better suited.
I agree in essence... but being brought up to be as economical (read 'lazy') as poss with the amount of work to get by - I've used interior latex as a primer. However, acrylic is far preferable to plain latex nowadays, and, since the original poster asks about primer in a steamy area, I think I'd still use a good alkyd primer first. [note to self -ask my paintstore owner]All the best...
To those who know - this may be obvious. To those who don't - I hope I've helped.
Buy your paint from a quality paint-only store like Dunn-Edwards, Sherwin-Williams, Benjamin Moore, etc. Tell them what you're painting, ask them how, do what they say.
-- J.S.
Acrylic can go over oil, pretty much for the reason the SW rep said.
The key is in the prep for existing top coats. The new coats of paint will not bond well with the gloss in the old finish The substrate to be painted needs to be cleaned and sanded to give tooth to the new paint.
I would normally wash the surface to to painted, sand and in some cases use a deglosser in prep for the new topcoat.
On walls I might use a primer like gripper or similar bonding primer. On woodwork,I might use a bonding primer depending on the condition of the surface
the key is in the prep
I went through this same problem about a week ago. I went to the paint store (Benjamin Moore) all set to re-paint the ceiling of our bathroom with an acrylic latex. After 15 years, it was showing some pealing especially above the shower. I brought the old paint can (a flat oil) to get a color match. The sales person said that for a problem area, like the bathroom ceiling, I was better off sticking with an oil. I purchased a low-luster oil since Beni-Moore no longer makes a flat. Good luck with whatever you finally decide.
ChipTam