If for some reason it becomes necessary to re-coat a Waterlox Original Tung oil finished surface with another type of coating, you can apply a surface finish over top of our Waterlox Original Tung oil finishes, keeping the following details in mind.
- If the last coat applied was our Waterlox Original Sealer & Semi-Gloss Finish, you will want to clean the surface with TSP (tri-sodium phosphate) and water, let dry. Do a clear-water rinse, let dry. Then, re-coat.
- If the last coat applied was our Waterlox Original Satin Finish, you will want to clean the surface with TSP (tri-sodium phosphate) and water, let dry. Do a clear-water rinse, let dry. Then, you’ll want to pad the floor with a Maroon pad and tack the floor to remove any residual sanding dust. Then, re-coat.
Since all types of finishing scenarios cannot be tested, the only fail-safe way to ensure that there won’t be an inter-coat adhesion issue is to conduct a cross-hatch test.
A cross-hatch test is an industry test for adhesion. Waterlox Original Tung oil finishes are penetrating oil finishes and are therefore best used on bare wood (does not refer to stain coat(s) if used). Sometimes, sanding the surface is not an option for a project. To test the adhesion properties of a combination of finishes, test on an inconspicuous area first.
Directions to test for adhesion: Scuff sand a small inconspicuous area with 320 grit sandpaper. If you will not be sanding the surface to bare wood in the actual project, clean the area with TSP (trisodium phosphate) and water and complete a clear water rinse. Apply 1 coat of Waterlox Original Sealer & Semi-Gloss Finish. Allow the finish to cure for 4 days. Scratch a “tic-tac-toe” board into the cured finish by cutting through the film and into the wood. Place a piece of Scotch® tape over the cross-hatch and press it down firmly with your finger(s). Pull one end of the tape off with a steady motion. If there is any film on the tape, other than the pattern of cuts you made into the substrate, this finish combination will not have adequate adhesion.
If the test fails, the system is incompatible.
