Homebrew PCBs

I use Adam's wet method - rinse the film and use a squeegie and hot
air gun to laminate it.  But, if you're just short of melting the
film, I think you've got that covered.

The film I use requires a 15 minute "rest" period after exposure - in
the dark and before the second cover film is removed - to fully cure.
Try to find instructions you can read.

I use NO mechanical wiping to develop.  Just drop it in the solution
and wait.

You may also have underdeveloped the film.  I got a step gauge to
calibrate with, but you may be able to calibrate without by
experimenting with a striped mask and finding the least exposure where
the exposed mask stays, and the most exposure before the covered mask
hardens.  Then choose something between the two.

Incandescent lamps may not be the best source of UV.  UV LEDs are
cheap enough to buy in bulk, or try sunlight, which is more variable
(weather) but high in UV.

If your film has two cover films, make sure you're removing the right
one first.