Flame test posts
Take a look at Dan Horton's posts regarding his flame tests. Date was around 13 June 2011. Takes a while to read, but very informative.
I've about given up on my "neatness score" with Proseal and Flamemaster, but here's what I ended up doing for sealing the shop heads of pulled rivets...
Get a syringe. Use a drill bit and slow drill speed to open up the hole so the material will flow thru easier. Otherwise its VERY hard to extrude the material as it begins to set up.
I used a short piece of 1/4" OD plastic tube and widened one end by forcing it onto an awl and heating it with a heat gun. This way the tube fits over the end of the pulled shop heads with a little room the spare. Install the non-expanded end of the tube onto your syringe.
The syringe can be loaded from the rear using a popsicle stick. Put on your nitrile gloves, loader 'er up, insert the plunger and go to work. Place the expanded end of the plastic tube over the shop head, extrude enough goo till you see it coming out around the base of the rivet. Spin the syringe once around to be sure sealent is applied all the way around the base, then pull it straight off and move to the next one. After a bit of practive, I was able to "seal-by-feel" even in areas of the tank that I could not see because the short tube keeps the rig located on your rivet as you sqeeze the material. Worked for me. Your results may vary.
Embrace the goo!