Latex Over Oil Base

[Brian Buckley]

I want to paint an exterior door with high gloss latex paint. It is currently painted with oil base paint. Do I need to strip the oil base (would rather take a beating)? Can I get away with lightly sanding the surface and then applying the latex paint?

Thanks

Brian

[Bob Noles]

Brian,

I think anyone you ask who works with paint will pretty much tell you that latex over oil will not work well. The reverse would be your friend, but in your case you need to take the up hill road. You may want to consider repainting with oil and save yourself some hassles.

Sorry......

[Richard Niemiec]

I'd sand the old oil paint heavily, as you don't have to strip it, then prime with a good quality exterior primer, then two coats of latex paint. Primer is important as it gives the latex something to hold on to. That's what I did about 15 years ago and the paint held up fine. Nowadays the latex paint has gotten even better.

[Nick Clayton]

Brian,

A couple of questions:
1) Why not use oil? 2) What kind of condition is the current door/paint in? 3) What type of sun exposure does the door receive 4) What type of weather does the door receive (ie, is thier a storm door over it).

Painting is something that I unfortunately have experience with; I grew up in a family with painting business. We all have an aversion to oil since it is a pain to clean, sticky and smells, but it lasts longer and will lay flatter and thin better. As you mentioned you want to go with a high gloss on the door, no latex is going to match the lustre of an oil gloss no matter what any manufacturer tells you. If this is an entry door, this is the focus of what people see as they enter your house, if you have the space and security, pop the door/hardware off and lay it flat so the the paint will settle smooth as it dries.

But before all of this happens prep! prep! prep! Bleach mildew, sand, prime bare wood, use automotive body filler to fill dents, sand/prime filler, and caulk joints. Gloss is sooooo unforgiving and will show every imperfection and a high gloss will only act as a catalyst to amplify them further. Feel free to pm me with any ?'s I'd be happy to help.

Cheers,
Nick

[Dennis McDonaugh]

Brian, latex won't be as glossy as oil, but I've used latex over oil with good results. First, make sure the oil is still adhering to the door well. This is probably the most important step. If the oil base is loose, the latex will cause it to peel off. Sand the oil well with 150 grit, then prime with a good primer. Kilz is good and I use their oil base primer because I can sand it before applying the top coat. Then sand with 220 and 320 because glossy paint shows up any imperfection. Then apply the latex.

[Cliff Rohrabacher]

You will want to consider the latex and whether it wants a primer first or not.

Benjamin Moore has upgraded from latex to 100% acrylic.

I'd start with Moore If I were thinking paint. .


On the other hand I am Comming to a position where I think that paints are all alike in one respect: They begin to fail the instant they are applied.

Thely don't do anything more exciting than sit on the surface grabbing a few lousy fibers for adhesion. That's not much.

Stains can be thinned with additional VOCs and penetrol and oil to increase penetration and adhesion and should last longer than any paint.
Better still are the industrial urethanes and epoxies.

There are single and two part urethanes as well as epoxies that will penetrate and seal the wood for more than twenty years never needing re-coating. The wood will have to decompose from the inside before those coatings fail.

I am about to do a 10 year old beat ~deleted~ weathered PT spruce deck (20*40 feet) with just such a urethane.

[Art Mulder]

You will want to consider the latex and whether it wants a primer first or not.

Benjamin Moore has upgraded from latex to 100% acrylic.


Cliff, Brian, everyone,

I just posted here about my http://sawmillcreek.org/showthread.php?t=35278 horrendous experience with trying to paint latex directly over oil without priming. And Cliff, it was acrylic latex, by CIL.

Now, this was an inside room, not an exterior door, but in my situation, washing and two coats of original Kilz primer (I wanted a good job, and so I just painted until the can of Kilz was empty) did a good job of prepping an oil surface for latex.

best,
...art

[Steve Schoene]

I'd second the suggestion to use oil based enamel. Buy the very top of the line. You will get better gloss, an easier time of avoiding brush strokes and more durability. So what's the cost? Cleaning a brush? For $15 bucks you can buy a perfectly good brush for enamel, and throw it away when done. You want good ventilation for latex too. It has stuff you don't want to breathe either, just not so noticable.

And, I also second the advise to be meticulous about preparation. Any ding or scrape that you barely notice now will stand out like a sore thumb under high gloss varnish. An exterior door will have picked up lots of stuff from the air, so before sanding anything, scrub it thoroughly with a solvent, using lots of paper towels so you remove it not smear it around. Sanding does not remove these contaminents, often just drives them deeper.