I run the batchmaking department for a large paint manufacture. 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. ... View related article.
