When you come back to the jar, you should find the bits all
dissolved and you now have a creamy paste which can be used to
fill the seams and any other imperfections in the parts. It can also
be used as a cement to glue reinforcements into the parts, such as a
ring inside the front of the cowl around the hole you cut for the
prop shaft. I smoothed my filler into the seams with a palette knife.
A flat blade screwdriver would also work well, or even a small flat
piece of wood. I filled the inside of the seam on my cowl to add
extra strength, also. The goo will come off of your tool pretty
easily with a paper towel while it’s still wet, or it will peel off when
it’s dry, but it welds itself to the plastic parts... it actually becomes
“One” with them.