I have never tried it, but obviously the stain would have difficulty penetrating the top coat and you may not see any change in color. A better option might be to sand the table and top coat with more poly with a dye added to it. The only downside is that any kind of damage to the table will show a difference in color, since the color is "on top of" the wood, not "in" the wood.Will oil base stain work over oil base poly. Not something I would do for myself but the alternative is make another coffee table. My son thinks the table does not go with his newly installed flooring.
Would a preliminary thin coat of poly after sanding act as a sealer and provide a more consistent dyed poly application. That is a good idea too, Bas. I never would have come up with such an obvious solution.I have never tried it, but obviously the stain would have difficulty penetrating the top coat and you may not see any change in color. A better option might be to sand the table and top coat with more poly with a dye added to it. The only downside is that any kind of damage to the table will show a difference in color, since the color is "on top of" the wood, not "in" the wood.
It's common to apply a thin coat of dewaxed shellac prior to staining with wood that is prone to blotching. The idea is that the porous areas will absorb more of the finish, so that when you apply the stain things will even out. I don't think polyurethane would be a great choice because you want to make sure the stain adheres properly. Dewaxed shellac is sort of the O negative of finishes, it's compatible with just about everything. There are many different chemical formulations for both stain and polyurethane, so you'd need to test for that. Having said that, oil-based over oil-based would probably work.Would a preliminary thin coat of poly after sanding act as a sealer and provide a more consistent dyed poly application. That is a good idea too, Bas. I never would have come up with such an obvious solution.