Painting - Oil over Latex vs Latex over Oil

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View Full Version : Oil over Latex vs Latex over Oil


telemaler
12-23-02, 05:13 PM
I am a decorative painter and seeking advice on the oil over latex, latex over oil quandry.

For years we backgrounded wood in oil-based paint but now use latex or acrylic paint for backgrounds. Many of us do the decorative art in artist's oil paints and have always used an oil-based finish over the top to protect the piece.

Some artists are now using water-based finishes over oil-painted art if the manufacturer indicates it is safe. Those of us old-timers are reluctant to do that.

Can you offer an opinion and rules for the oil over latex and latex over oil quandry and if you think water-based finishes over oil-painted art is a safe alternative?

Thank you for your assistance.


chfite
12-23-02, 09:10 PM
For artwork, I doubt that it matters. In the long run, the only differences between alkyd and latex finishes are in the way they 'cure'. Alkyd paint oxidizes over time into a rigid, impervious film. Latex dries and bonds into a semi-permeable, flexible film. These characteristics make them different, but not necessarily imcompatible.

If you want a finish that is tough and ready to go tomorrow, then alkyd will be there in 24 hours. Latex takes about 7 days to reach maximum hardness. Moisture will be trapped behind alkyd finishes due to the impermeability. Latex on the other hand will allow moisture to transpire through the finish and escape. The new water-based finishes wear as well as any alkyd finish, once the drying time is past.

The drive to develop more serviceable and durable water-based finishes has come from air quality restrictions on the amount of volitaile organic compounds that can be released into the environment. Or course, ease of cleanup and resistance to chemicals are matters of necessity in choosing one finish over the other.

Some water-based polyurethanes are almost impossible to remove with chemicals.

So, the choice is up to you.

telemaler
12-24-02, 08:23 AM
Thank you so much for your comments. I truly appreciate your assistance. You have convinced me to try it.