Need help painting plastic armour

[RvanAken]

Here's my problem. I'm building a custom mandalorian armour for the Dutch premiere of star wars ep7. If been working on it of and on for about a year now just for fun but the next movie gives me a nice death line.

I've made the chest, back and shoulder pieces from new white plastic buckets which gave the plates a nice curve to fit my body and painted them using spray paints for cars. At least the groundcoat and a layer of chroom paint to give it a nice metal look. I used the liquid latex technique to get the paint chipping effect using acryllic spray cans for the rest of the layers ending with a few coats of clear.
The effect was great.

But now (about 10 months later) I decided to add a few straight green lines to the armour parts using masking tape. I used tape special for delicate paints minimizing the change of damaging the paint job I already had. And you guessed it, it took the paint clean of.

I forgot to do a smal test piece first so all the pieces need to be painted again.

I've been testing a few basecoats this weekend using the same paints I used for my helmet because I didn't have any problems with making tape on it.

But again the tape removed al the paint from the plastic.

Any tips on how to prepare the plastic before painting, I'm kinda out of idea's right now and I really need some advice.

Thanks
-R-

 

[division 6]

Did you sand the plastic first?
Most plastic containers don't take paint very well since they are made to resist stuff adhering to them so you need to rough up the surface to give the paint something to grip.

I've read of many getting good results with using Krylon paints made for yard furniture as a base.
Don't know if they sell that product on your side of the world.

 

[Trooper_trent]

Yup, sand the plastic first and use a good primer. The primer will hold to the plastic and the paint holds to the primer.
I've had more than my fair share of pulling the paint off with the tape.
If you don't want to redo the whole thing, the good news is you can always just paint over the flaked parts with silver and a wash or two to make it looks like weathering.

 

[RvanAken]

Oh, I sanded the plastic all right, and I used two different primers. I've got one last primer to try and if that doesn't work ill need to find another way of masking without using tape.

I'll give it a try tonight and let the primer cure all night before I'll put the first test layer on tomorrow. And I'll let that cure for a day and test the tape again.

-R-

 

[RvanAken]

I just asked myself the question: Did I use a to fine a grit of sandpaper? I used a 180 grit paper before so for this test piece I used a 60 grit paper.

We'll see what happens

-R-

 

[division 6]

Let the primer cure several days, a week is better.
Same with your base silver layer.

 

[RvanAken]

The can says that the curing time is about 2 hours but I'll let it cure for a few days, thanks for the advice. Fives me time to get new liquid latex, half the bottle dried out. But I had it for about 4 years now

-R-

 

[usajdm]

I'd like to also add that you must clean the plastic very well.
Those buckets are sold with the release agent still on them.
I suggest a strong degreaser.

 

[superjedi]

You could try to find an "adhesion promoter." This is a spray that goes on the raw surface
before the primer. In the states, there's a widely available brand of auto paints called Duplicolor
and they make an adhesion promoter that works really well. I just used it on a Boba Fett
helmet that I'm working on.

 

[RvanAken]

superjedi , thats worth trying. I'll try to find something like that. Any Dutch people around who could point me in the right direction?

As a test I put son acrylic primer on a a piece of chroom foil, just to see how it will stick

-R-

 

[Wade Vox]

Check out the mandalorian mercs for help as well. They specialize in custom mandalorians.