I have a CNAT that is developing some small cracks in the ends. I am afraid that it will split one day if I do not seal the stone. I also have a couple of other natural stones that might benefit from sealant as well.

I know that the traditional sealant for natural stones is Urushi, but it is difficult to obtain and may cost as much as the CNAT I am trying to protect.

I know people have used fingernail polish, but I would prefer to avoid the acetone fumes.

I wondered if anyone has tried using Minwax Polycrylic which is a water-based combination of polyurethane and acrylic. I have used it successfully as a wood finish, but do not know how it would work on stone.