A "dollop" sounds about right
Tony, it was a pleasure to meet you at the RV-12 expo!
Ditto's on the hanging chad. If one spins a rivet in pro seal and then inserts thru a hole, you end up with a spot of goo on the very tip of the rivet without much contact area for adhesion, waiting to float off into the fuel.
A "dollop" will adhere the "chad" all around the rivet and onto the inside tank surface around it. Much tougher to come loose that way.
The Synergy gang at the Expo also mentioned applying a dollop with a popsicle stick. Makes me feel much better about my firewall. It looks like I've put a "Hershey's Kiss" on top of each rivet.
Here's what I did to seal the rivets inside the tank. I dipped the end of a small piece of fuel line into the goo, then slid it over the top of each rivet and gave it a spin. Guaranteed a uniform layer of goo around each rivet even if I couldn't see it well. In fact, some of 'em I did by "feel".
No guarantees. Always looking for more ideas to make the "Mark V" tank even better!
Clear Skies,
Dave