So I've got my raw hard maple butcher block countertops and I've been experimenting with poly finishes on the underside. I have been using Minwax clear and satin oil based poly, trying some patches of wood with full strength and some with poly diluted with mineral spirits. So far I don't see much difference between the two although the diluted obviously goes on thinner. I have 3 coats of clear poly full strength and it doesn't look all that different from the diluted test patch, except you can feel the difference to the touch. I'm beginning to wonder what the point is if I put on 3 full strength or 6 diluted and end up with the same thing? I'm concerned that too few coats of diluted poly won't provide the protection I need. How do you know when enough is enough, and is it usually recommended to lightly sand the final satin poly coat?
And finally, concerning wood protection I am finding out just now that poly isn't really impervious to liquids. I'm hearing from Minwax directly that the oil poly is more resistant than water based, but it is not going to protect the wood from all liquids such as a wet glass of ice water. Now I'm wondering if I'm barking up the wrong tree with poly. I'm being told now that the only true ironclad treatment to protect the wood is conversion varnish that has to be applied with a compressed air spray application, which I cannot really do practically. I've called a couple of guys to get a price on this, but may just end up with the poly after all, and I guess just cross my fingers that the poly will do OK. Maybe I need a couple of extra coats...
Any thoughts or advice on this long winded message are appreciated.
dwhite