Instructables

Step 7: Step 6: Epoxy

This is the "funnest" part of the whole project.

Step 6:
-When the pennies are all glued on, it’s time to put on the bar top epoxy.
-Follow the instructions on the package and do accordingly.  For mine, I had two separate containers of Resin and Hardener.  I had to mix EXACTLY the same amounts of each for about two minutes with a popsicle stick.  This ensured the compound was evenly mixed for prime drying and finish.  This part is kind of fun to do, but after the epoxy is mixed, pour it over the pennies.  Make sure you are on a flat surface so the epoxy doesn’t dry crooked.  Take the popsicle stick, or plastic putty knives, and spread the epoxy evenly across the surface of all the pennies.  You should be able to get away with one layer, but if you have to do more, follow the package instructions. 
-Let the epoxy completely dry for about 72 hours.  This will give it time to harden and cure before use.  DO NOT TOUCH THE EPOXY!  I did, and it left a dent/ripple in one of the corners of the table, of course it’s not very noticeable, but frustrating!