What's that stuff they use on clocks that's really thick and clear to
coat them? I have a clock I made in the 8th grade woodshop that has
this stuff on it. If I recall correctly (this has been some years
ago) it was in a gallon and the teacher made us stir it for half an
hour before we could use it. Don't remember if it was two parts or
not, just that it was damned thick.

He used a blow torch to heat all the bubbles out of it after it was
applied, if that helps. The clock hasn't yellowed at all, so I know
it ain't polyurethane.