Doors and Windows - Oil Base over Latex

My steel insulated doors were originally painted w/ latex almost a decade ago.
Can I apply an oil based enamel over it?

In my experience, and I'm no expert, oil based paints will go over latex , but not the opposite. However, with the high quality exterior latex enamels available... why risk it?

It is unwise to apply oil based paint to a steel door, due to thermal expansion of the door.
Latex remains flexible, whereas oil becomes brittle, & has a tendency to split (alligator).
There is no other reason to avoid oil-based paint on the door.
The old latex on oil & vise versa "rule" is misinformation, & is unjustifiable.
I believe that because of the rubbery nature of many latex paints, they were not sanded properly. The next paint job delaminated, so the new paint was blamed. It would have failed no matter which base paint had been applied.
We now have bonding primers that largely eliminate the adhesion problem, but sanding is advised even under them.

I personally prefer oil-based on interior trim, due to quality of finish, ease of prep for "the next guy", & a thinner buildup of paint on moldings.

I prefer oil paints in general, but many exterior applications dictate the use of latex. Steel doors being one.

In my experience, and I'm no expert, oil based paints will go over latex , but not the opposite. However, with the high quality exterior latex enamels available... why risk it?


other way around. latex over oil, not vice versa. oil needs to penetrate to stick. latex creates a film and prevents penetration.

Musta been after 9am when I thought about it :cool:

I know I have problems with one or the other bubbling/crackling/orange-peeling when applied over the first.... last time I re-painted baseboards it ended up a nasty mess and I ended up replacing them... Now I stick to latex.... though I may be thoroughly misinformed.....

According to the Paint Quality Institute: The rule of thumb is that, given proper surface preparation, for exterior use you can apply quality latex paints over oil-based, but not the reverse. However, if you have many layers of oil based paint, stick to using oil on oil. For interior use, generally you can use one over the other. Some manufacturers of latex products will recommend a primer when going over oil-based paint.