Hi All,

I spoke to MinWax and the women was extremely knowedgable. She said
the following:

1: The stuff on the bottom of the can that was so hard I didn't know
it was there was only the flattening agent (silica)
2: The solvent in spar urethane is mineral spirits, it soaks into the
fibres first and can take a while to off gas
3: What it needs is air circulation - eventually it will cure
4: Wiping the surfaces down with mineral spirits now can help it cure
faster

So, I'm going to leave these table tops (1 at a time) outside until
they have cured. I still have enough table space with 2/3 of my desk
(my whole desk is about 60 square feet!)

Thanks to all for your help in this matter.