A common question we get asked is: ” Can oil based and water based products be used over each other?” And the answer is, yes. But the underlying finish has to be absolutely dry. The first situation is a water based top coat over an oil based stain. Allow oil based products such as Java gel stain to dry at least 72 hours before coating with a water based topcoat. The reverse scenario, is using an oil based top coat over a water based stain or milk paint. Allow water based finishes to dry at least 24 hours before applying an oil based product. Dry time are always effected by temperature, humidity, application and the existing finish. Ideal conditions are 70 degrees Fahrenheit and 70 percent relative humidity. Be patient with the drying time of the first coat of an oil based product. The first coat sets the stage. It would be like laying a dry blanket over a wet sheet. If the first coat is not dry before the next one is applied, the final coats may never dry. Two things we’ll tell you if an oil based product is dry. Its no longer tacky and you can’t smell it. You can tell if a water based product is dry by touching it. If its cool to the touch, its not dry. But finally if you can sand it and get a good powder out of it, It tells you your finish is dry. Last note: Oil based top coats amber over time. DO NOT use them over white or very light colors. Here’s a door we finished with Snow White Milk Paint and them finished it with Arm-R-Seal Satin. Compared to the same piece, finished with High Performance. You can see the yellow tone of the Arm-R-Seal on the door. So to answer the question, Yes. Oil and water can be used over each other.