Do not use them over white or very light colors.
Oil based clear coat over water based paint.
Oil based over water based when using an oil based topcoat over a water based stain or milk paint allow water based finishes such as hp topcoat to dry at least 24 hours before coating with an oil based product other tips oil based finishes amber over time.
Polyurethane can be oil or water based and you can use either kind over latex paint.
Luckily there are ways around this when it comes to applying finishes.
If you already laid down a water based finish and decided to go for an oil based one do not fret.
Jim carroll explains why it s not only acceptable to use a water based finish over and oil finish provided you do it correctly but that it can be the best solution when you want to bring out the natural character and color of the wood.
Apply at least two coats of water based paint over oil based paint.
In particular painting with acrylics over oils usually has poor results.
Polyurethane finish over oil based paint it works well but be aware of the re coat window.
Oil based products and water based products typically do not work well together.
If you desire a truly clear coating over your latex painted surfaces and wood the use of water based poly will be better than oil based.
You should never put a water based finish on top of an oil based finish.
Question can an oil base paint be coated by a polyurethane clear coat finish.
As an example acrylic paints should not be used over oil based paints.
Play it safe and seal the stain with shellac.
The water based coating comes with a clear transparent coating while oil based have amber hue which yellows and will continually dry with time.
This is mainly because the drying times of water based products and oil based products are different.
With a little bit of extra time and preparation you can apply the oil based finish right over the water.
I would suggest just scuff sanding the oil based.
However the curing time can be several days especially with an open grain wood such as oak where the stain can sit uncured deep in the pores.
Oil and water are famous for repelling one another and not mixing.
What would the process be to correctly coat this project.
Oil based polyurethane will not bond to water based paint.
Using a brush roller or paint sprayer apply at least two coats of a high quality water based latex or acrylic paint e g.
However oil based polyurethane tends to yellow as it ages whereas water based varieties stay transparent.