Latex Paint Applied Over Oil Base Paint Without Priming

Questions & AnswersCategory: Latex Paint Over Oil Based PaintLatex Paint Applied Over Oil Base Paint Without Priming
Anonymous asked 9 years ago

I have a real problem. A contractor applied latex over oil base paint on interior doors and trim. The latex did not adhere and can be stripped off easily with a finger nail. He does not want to strip off the latex and repaint. He wants to sand and paint over with some other type of paint. I believe that the bond will never be any stronger than the present one. Must the latex paint be stripped off before repainting?

6 Answers
Crowder Painting answered.

This is a very unfortunate problem. Applying latex over oil base paint without priming first hardly never works, even when the paint can says it should. Your painter is looking at 4 options and trying to find one that will fix the mistake without causing major him financial hardship.

Option #1 is sanding off the loose paint, feathering the edges and repainting, probably with an oil base paint.

Option #2 is sanding off all the latex paint, priming and repainting.

Option #3 is using a chemical stripper to remove all the latex paint, priming all affected doors and trim, then repainting with either an oil base or latex paint.

Option #4 is replacing all affected doors and trim with new doors and trim.

Option #1 could take the least amount of time, but could easily turn into a complete sanding of all doors and trim, example option #2. Go ahead and have your painter test the sanding method to see how the paint comes off. Sanding works best on flat surfaces only and the fresh latex will have the tendency to become gooey as the friction heats it up. This is just one problem your painter will run into.

Option #3 is probably the best as it will remove all the latex paint allowing your painter to undue this mistake, but will be the most difficult in both time and materials. There is a chance that stripping could loosen the original oil base finish. In order to lessen the chance that the stripper will damage the original finish, a mild paint stripper could be used. I have used Ready Strip in the past with good results.

It seems that your painter is trying to fix his mistake and this is a good thing. I would like to see a solution that makes you both happy. You are right in assuming that all of the latex paint should be removed. After its removal I recommend applying an oil base primer then repainting. Work with your painter in order to have this job done right without breaking his wallet.

All that was needed before painting your trim and doors is identifying the original finish (denatured alcohol on a rag is all that is needed), apply a good quick drying oil base primer and finally apply 2 coats of quality latex paint. As you can see 2 steps would have prevented this problem. It is always a good idea to prime first when applying latex over oil base paint.

Anonymous answered.

I am going to fix the same problem for a client soon. My method is to take a D.A sander -orbital sander and sand off all doors and jams, the base boards and casing I will replace its cheaper in the long run. Next time hire a professional painter and you can always test your trim by using denatured alcohol- if it comes off when rubbing with a rag with denatured on it it is latex if it does not come off it is oil. Hope this helps.

Anonymous answered.

I have a door a old door with lead based paint in it. I need to paint it and then rehang it. I scrapped all I could then feathered what was left. What do I have to do to it so I can use latex paint on it?

Crowder Painting answered.

Wipe off the dust with a damp clean rag, let dry. Now prime the door with a good quick drying oil base primer. Zinsser Cover Stain works good. After the primer has dried you can paint with latex paint.

Anonymous answered.

There are latex products out the that will go directly over oil base finishes if they are properly prepared(lightly sanded with 180 grit sandpaper and wiped down to remove dust) Porter paints Advatage900 is a good example of this. I am a professional painter and have used it for years, it is a hard finish and is fairly easy to work with. I still prefer oil base on trim work when possible, it will hold up longer, but this product is the best latex alternative out there.