Painting - Is that previous paint oil-base or latex?

We're preparing to repaint some exterior metal doors and plywood porch ceilings that were painted 13 years ago when the house was built. We'd really like to use latex semi-gloss, but we're afraid the existing paint may be oil-base. Is there a way to test the existing paint and find out for sure?

I know of no simple test to determine oil from latex other than each has a distinctive look about it.Homeowners now have an option with waterborne enamel.This material will bond to oil or latex and has the properties of latex.The only thing you will encounter is it tends to dry a little fast.Let the doors be the last thing you do so you are up to speed on your painting skills.Sherwin-Williams and Devoe both have a very good product.

In any case, oil or latex, you will need to prime first. I suggest using Benjamin Moore's alkyd oil primer ( it grabs to anything ) and top coating with Benjamin Moore's MoorGlo- premium exterior latex. It's real paint! Good luck!

There is a very simple test to determine if an existing coat of paint is latex or oil. Put some denatured alcohol on a rag and rub an inconspicuous spot. Latex paint will dissolve and leave a residue on the rag, and oil paint will not be affected at all. Denatured alcohol is great for removing spatters of paint off of hardwood floors or stained woodwork, too. It will not affect varnished or shellac-ed finishes.