Preparing plastic part for painting

[Z2TT]

Hello,

I have been reading on many websites on how to paint plastic parts, and so far this is going to be my procedure. I am not sure if its the correct way so please correct me people I always like to learn.

I have good equipment and a lot of space, 2 guns one is a Devilbiss and a large air compressor with 40L tank.

I want to avoid cracks also, as my previous part has hairline cracks now.

I am painting the plastic section of a mudguard from a Z20 Soarer. It has a few chips so this is my proccess.

Please correct any of my steps, add/remove steps and give suggestions. I'm not sure if the grits im using for certain steps are correct.

I dont know what exacly i need to do before painting, do i need adhesion premoter, plastic primer, primer sealer this all confuses me.

1. Sanddown with 400 wet dry

2. Use car body filler to fill in chips and cracks

3. Sanddown car body filler with 200 then 400 wet and dry

4. Wash with Wax and Grease remover then use cloth to remove any dust

5. 2 Coats Plastic Primer (Does this need to be mixed with flexing agent to prevent
cracking?) and sanding between coats if needed, 400 then 600 and wipedown with cloth between coats to remove dust

6. 2 Coats Normal primer (Does this need to be mixed with flexing agent to prevent cracking?) and sanding between coats if needed, 400 then 600 and wipedown with cloth and wax and grease remover between coats to remove dust

7. Sanddown with 600 before applying colour coat

8. 2-3 Coats of Colour, sanding between coats if needed with 800 grit and wipedown with cloth and wax and grease remover to remove sanding dust.

9. Do I need to sand the final colour coat real finely using 1000+ grit, or just the usual 800.

11. Wax and grease remover and wipedown

10. Apply Clearcoat.

11. sand with 800 then 1000 upto 1500 then polish.

Any help and suggestions appreciated.

Thanks.

[MWP]

Sounds good.

Although maybe this thread should have been named plastic bumper/bodykit painting?
These are pretty much the only plastic part i can think of thats big enough to warrant (or be able to do) this procedure.
Most smaller plastic parts are too curvy or have too many sharp edges to be able to do the above.

Its pretty much the same as painting anything else except for the use of a different primer.

For smaller parts (like parts in the engine bay), i just clean with degreaser, and then spray with a decent vinyl paint. Vinyl paint is thinner than normal paint and will partly soak into the plastic and all the small gaps, etc giving a hard, thin & even coat with little effort.

[Z2TT]

Thanks.

What i'm unsure on if is my grits are correct and im not sure what I have to mix with flexing agent, I know i have to add flexing agent to the paint, but Do i need to add flexxing agent to the plastic primer and normal primer?

Do I need to sand the final colour coat before i apply the clearcoat, or sand only the clearcoat and not the final colour coat under it.

I use Acryllic Lacquer, is that good to use on plastic parts or is there a different paint that should only be used with plastic?

[JP]

I use a high-fill bumper-primer instead of plastic adhesion promoter and flex-add.

I sand with 320grit prior to prepwashing and priming the bumper then do a few coats of bumper prime and wetsand with 400grit, then apply the basecoat acrylic (2-3 coats) and then 3 coats of clear. I add a little flex-add to the base and clear. Dont sand the last coat of colour prior to the clear

Jason

[Z2TT]

Thanks ,

Few questions.

1.

Whats the reason for not sanding last coat before clear, does it look better not sanded?

2.
So do i only need one type of primer? Bumper primer and then after that can i put my colour coat ontop of the bumper primer?

3.
If i use adhesion premoter, can I put colour ontop of that, or do i need to put a different primer ontop of the adhesion premoter before putting the colour coat on?

4.
Does the bumper primer need flexxing agent put in it?

5.
Does adhesion premoter need flex agent, pretty sure answer is no but just need to make sure.

6.
Do ALL colour coats need flexxing agent? or only the one before clear.