A mate of mine who used to do restoration paint jobs and I have no experience with 2 things.

1. how do you use plastic primer? There is no specific instructions on it.

2. how long before you apply clear coat after the metallic? any specific number of coats?

The plastic primer may have dozens of different ways it needs to applied, depending on many things. What brand primer, what name primer, what colour primer, what type of plastic. I would be doing web searches based on a bit more info.

Clear goes on top of metallic after the coverage of the base coat is complete and there is no signs of transparency, mottling or too dry a finish. This may take 2 coats of base or up to 15 coats to get right depending on many factors. Unfortunately experience with using the product is one of the main factors.

plastic is PP. the primer is paint mobile's own brand. they said just spray it on the plastic. duh

its clear and smells like thinners, pretty much looks like thinners to me. looks like an adhesion promoter to from what I have seen in screen printing?

ok practice panel on the clear then.

If it is a clear plastic adhesion promoter, then you just spray it on. It sometimes has a metallic additive so you can tell you have put a coat on everywhere.

Ideally plastic being a very flexible product does not finish well with thicker layers of finishing products on it. So by using hi Fill which is a solid stable hard product, it will eventually crack and fail. The time it takes depends on the rigidity of the base plastic. The difference in flexibility between the original plastic and the thickness of the harder product on it are so varying, it all depends on how thick the product is and how long you want it to last.

PolyUrethane parts last about 12 months with more than two coats of paint.
PPE parts can last many years.

Just too many variables to have a simple list.

its on non flexible bulk of the bumper. they don't move much at all, if it does on this car then you have crashed it lol

the marks are very minor, mostly me struggling to get the paint off even with strong paint stripper trying to be careful with the scrapper. is it best i try to block sand them out rather than hi fill? plenty of plastic except it doesn't sand easy, feels greasy when sanding.

there was hi fill already under there in one spot so far, I couldn't see the point though as the plastic was perfect there.

whats the temps and humidity limits that are safe to paint in for the different products I am using.

etch primer, wattyl brand

high build primer, paintmobile brand? maybe protec rebadge?

color top coat, protec

Clear, paint mobile (relabeled protec brand?)

All are acrylics

The weather is rapidly turning back to winter (Victoria for ya)

So I just want to know whats still safe and wont cause issues and if I ran out of time is it ok to sit in primer for 7 months for the next round or warmer weather?

afaik acrlic primer can not be left for that long without top coating
etch primer not needed on plastics ( the plastic primer is your etch primer)
ones i have used say lightly scuff plastic surface after cleaning with wax and grease remover
high build primer should be alright but light coat only..as above .finished surface needs only enough paint to cover
thick is your enemy
assuming coverage of colour coat is adequate clear goes on when base dry so same day
make sure you have a filter in line to trap moisture before going through gun especially if humid
high teens temps should be fine

ok thanks for that. Ok I should be ok for another month I think. yes i run a water trap/filter works well.

minor wobbles in the metal should be spot putty or fine filler? if finer filler do i go on the primer or does it need to be bare metal?

The worst of the wobbles are about 1 -1.5mm thick.

I am trying to find a good bumper thats had no repairs. no luck yet. if the color is mixed up, can the remainder be stored long term, like the 7 months? ie. do everything but the bumper then do that latter from the same mixed batch for correct color consistency?

I am not sure if I will find a perfect bumper in time to paint.