Preparing for respray

[bas]

OK i've decided to respray my bumpers, and I have a vague idea of how to prepare them however looking all through the net for info there seems to be mixed reviews on how to do it.

Whats the best way and what do you guys recommend?

[MH999]

If the paint is faded with some stone chips then id use 320grit with a hard block(or electric sander) to feather those areas out and use a scotchbride pad to sand areas where the paint is in good nic, once done use finer sand paper to smooth
out and get rid of some of the scratches left behind.Then use wax and grease remover (prepsol) and wipe it on with one rag and wiping it off with another rag
then apply top coat,or if you want to do it properly then use acrylic primer(2 pac primer is even better) first, id say 3 or 4 coates ,then once dried use 800grid paper and wet sand.When done repeat wax and grease then top coat.After top coat if the paintwork has some orange peel,small runs then allow
up to 3 days to dry and then colour sand with 1500grit paper wet sanding with hard block.once done then use a buffing compound and polish.Thats how i would do it and i hope that all this makes sense

[bas]

Ok thanks a lot fot that MH,

is it nesisary to primer the whole thing?

[rock_it]

I was sure we use to use an additive to the paint when doing plastic.. So it would flex with the plastic..

[bduffman]

DO NOT use wax/grease remover as the final cleaner on raw plastic. it can bring out the mold release agents in the plastic and ruin the paint - or at least compromise it in the long term (cracking, flaking)
also it can build up static charge attracting more dirt to the finial paint work
if theres no damage to the paint you just need to take the clear coat off sand it back to make it look like matt colour then clean and spray over it no need to go back to bare


there was a good write up on the fiberglass site im a member of but i cant seam to find it

[bas]

Ok guys so far i have

-sanded both bumpers back using 400grit so they're nice nd dull.
-sprayed primer filler in areas of minor indentations.

Does the next step require primering the whole bumper and wet sanding back?

Or is it not necessary to primer the whole thing.

[MH999]

I would do it, but you dont have too.

[bduffman]

primer basicly is a sealer so if the plastic isnt exposed then it is already sealed by the old paint

[payaya]

Ok guys so far i have

-sanded both bumpers back using 400grit so they're nice nd dull.
-sprayed primer filler in areas of minor indentations.

Does the next step require primering the whole bumper and wet sanding back?

Or is it not necessary to primer the whole thing.

I would prime the whole bumper. Yep if your finish is not totally smooth wet sand it until it is. If your finish is not totally smooth you will have a dull ruff finish when you are done.

Make sure you spray wet and not dry!!! Read up about it if you are unsure. Make sure you use clear if spraying acrylic.