How to get paint to stick!!

Hey team, i'm restoring and adjusting a few G1 junkers i have lying around and most of them need a repaint. I've been using automobile touch up paints and they just don't seem to stick. They scratch easily and chip with minimal movement.
What paints are the best and how do you go about getting them to stick.
Ive been preparing the area by removing all the old paint, then sanding with a 120 grit sand paper. I then apply a grey base coat and then 2-3 layers of the colour i've selected. Is this correct?? Do i need to apply a clear coat as the finishing touch? Will this method work on plastics also?

well i wouldnt be using 120 grit thats really coarse i used 800 grit minium (get the wet and dry stuff) try autopro or a hardware store to find some

tamiya's spray cans are pretty good ive used one on a classics hot rod and havent had any problems, clear coat is up to you depends on how glossy you want it

Depends on the severity and colors.

Tamiya gloss white paint has been very good for me when it comes to restoring white die cast Autobot cars such as Jazz, Prowl and Red Alert. Tamiya gloss red has also done wonders with red die cast cars such as Sideswipe.

The trick is not to paint over the whole surface but with a fine brush, you simply cover up all the scratches. Once it dries, the result always amazes me as it blends in really well; what once looked like a horrible surface with multiple scratches ends up looking very smooth and minty and with minimal effort too.

Unfortunately this methods fails badly when it comes to plastic surfaces so you are better off using H2O2 or if the plastic originally had painted detailing, the matching tamiya color with a thin brush. Reprolabels also do wonders when revitalizing old toys.

WARNING: Don't spray a G1 metal surface with spray paint, it will act more like paint remover and 'wipe' much of the paint off. G1 Die cast isn't really painted on and looks more like a weird form of vacuum metalizing as the 'paint' is 'wrapped' tightly around the metal surface and when it chips or flakes, it is in noticeably thick bits.



BTW: Since this is a 'repair' thread it will most likely be moved to that section in the near future by one of the admin staff.

(moved topic, with a 4-day redirect for people to still see it in the higher traffic Qs section)