I should have researched first

[Wayne Elliott]

I think I followed the directions in the book "Understanding Wood Finishing" by Bob Flexnor for finishing mahogany. With no other preparation, I brush applied a varnish, Zinsser Bulls Eye Spar Varnish. After four days, it's still not dry, so I tried to lightly sand it with a 400 grit paper. I've now made a complete mess of this table - see two attached pics211498211499. Obviously, I should have done my research before rather than after (what did we do before the internet?), but does anyone have a suggestion about how I can save this project.

[Bill White]

I've not used that exact product, but a heavy brush coat will take a while to fully cure. Don't get impatient. Wait a week or more, then test for hardness. I would then sand with a surface lube such as an oil, buff to a nice satin sheen, then wax.
Bill

[Dale Cruea]

I used Zinsser Spar once. It took a very long time to dry. I put way too much on. I remember from someplace that you can/should reduce spar by about 25%. I can't find where I read that though. This should sand out when the finish dries completely. You can use a little mineral spirits to sand with.

[Scott Holmes]

I have some not so good news for you...
Spar varnish is for EXTERIOR use. It is softer and LESS water resistant than interior varnish.

I suggest you use a chemical stripper and start over.