This may be old news to some but i just stumbled on the best putty filling idea that works flawlessly.
I never could get the edges to feather up nice a clean before \
On the L-700 TAT build im doing, i was using the putty to fill in the area i put the cab hinge tube in and thought to myself,Self, that putty looks porus?
So i thought why not cover the putty in water thin ca,cure over night and see how it works and sands
I take Bondo spot glazing putty and apply it to the seam or what ever else needs filling.
Let that cure over night.
Cover the putty aera in ca,cure over night and wala!
It sands and works almost like its styreen