how easy is the cap to remove with teflon tape on the threads?

right now i can take the cap off with my hands and i dont need a wrench, will i need a wrench with teflon?

Sorry, i didnt explain my self well enough.

1.First I put the plug in the end but i dont ram it.
2.Then I put the fuel in and screw the cap on.
3.Then I ram the plug down (I had heard theis compresses every thing and makes it work much better, on my first gun i always did this with out problems so ...

Has any one had problems with fumes leaking out the back of the gun when they ram the projectile down?

I built a BBQ igniter into a cap for my gun and sealed the holes for the wires and such with RTV. When I ram a foam plug down the barrel there is a hissing noise and the plug goes down way too ...