Replies

1. 
   fivebirdscustom | Nov 08, 2020 10:06am | #1

   I put grain filler in over shellac a lot of the time. But, I can't guaranty anything.

   You could try more of the same WB Poly with some colorant. Maybe some epoxy?

   Best advice is to contact the finish manufacturer to get the honest, accurate answer.

2. 
   bilyo | Nov 08, 2020 12:27pm | #2

   My first inclination for problems like this is to use clear epoxy. However, I'm not sure how well it will adhere to the WB urethane. I suggest that you take a piece of scrap, apply 2-3 coats or the WB and then try appying some epoxy and see how well it adheres.
   If this was bare wood, I would have no hesitation. However, not knowing how thick your veneer is or what was used to glue it down, I will not advise you to sand off the finish. However, if adhesion is not a problem, you can fill the cracks with clear epoxy, sand it smooth, and apply additional coats of finish and the repairs will virtually disappear.

   Follow-up: Having said all of the above, unless those cracks really really bother you, I think you should consider leaving them alone. They are part of the wood and the character and they have a natural beauty of there own. Trying to "repair" them has the risk of ruining the beauty the top already has.