painting plastic

Irish · Full Member Joined: Jun 12, 2007 Posts: 250

Is there a special paint or technique to paint motorcross fender/tank type plastic?

KYLEPRESTON · Posted: September 30, 2007, 6:40 am Post subject: Re: painting plastic

I believe you need to us an acid etching primer first to get a decent result. I can ask my cousin he actally does plastic welding.

Cheers KYle

Irish · Full Member Joined: Jun 12, 2007 Posts: 250

that would be great, thanks

racer7x · Full Member Joined: Jul 27, 2006 Posts: 30

Krylon has paint specific for plastic in a rattle can.

grizld1 · Posted: October 4, 2007, 9:23 pm Post subject: Re: painting plastic

Right, Krylon Fusion; limited color choice, but it adheres great, rubs out nice, flexes with the plastic to resist cracking. If you're shooting out of a gun, buy an additive for plastic where you get the paint.

Irish · Full Member Joined: Jun 12, 2007 Posts: 250

What prep is needed when using the krylon?

KYLEPRESTON · Posted: October 5, 2007, 11:09 am Post subject: Re: painting plastic

I SHOULD IMAGINE YOU WOULD NEED TO CLEAN AND PREP THE SURFACE OF THE PLASTIC LIKE ANY BASE METAL. GET IT DOWN TO JUST THE PLASTIC. LEAVE A LIGHT TEXTURE(600 WET GRIT) TO THE SURFACE AND SPRAY AWAY. DO A LIGHT 1000 GRIT WET PAPER BETWEEN COATS 4 TO 5 SHOULD DO I THINK LESS IS MORE WITH PLASTIC AND CLEAR UP TO 4 TO 6 COATS GIVES A DEEP GLOSS TO THE FINISH.

Irish · Full Member Joined: Jun 12, 2007 Posts: 250

cool thanks man

georelle · Posted: October 6, 2007, 2:11 pm Post subject: Re: painting plastic

This is the general steps I take when painting. Follow the directions on the can. It depends on how it covers. Usually prep by wet sanding with 320-400 then no sanding between coats if it is within the time widow, i.e. wait for the previous coat to get tacking but not dry. After it has dried at least one week then I would wet sand it. Depending how it turned out you may be able to get by with wet sanding with 1100 if it is a little rough 800-900 then 1100. If it comes out perfect you may not need to sand at all, but there will always be some orange peel. After wet sanding use a polishing compound and wax.

Good luck

MaxM · Posted: December 2, 2007, 3:58 pm Post subject: Re: painting plastic

A few extra points on painting plastics.

When painting, particularly new and un-primed parts, it is essential that the mould release agent and any other contaminants are removed.
Do this in three steps:
1) Wash with a ph neutral soap and water which should be as hot as yer pinkies can stand.
2) Now clean with isopropyl alcohol which will remove any non-water-soluble mould release agents.
3) Finally clean with a wax and grease remover.

Clean inside and outside surfaces regardless whether they will be painted or not - it will prevent cross contamination from one side to the other.

You must make sure that ALL release agent, oils, greases and any molluscs that may have taken up residence are removed - if unsure repeat the processes above.

Next step is to scuff the surface - do not use a coarse paper, 800 - 1000 grit is as rough as we want to go - less is more. We are dealing with a soft material here and a coarse paper will tear it apart and leave deep scratches.

Also, don’t be tempted to combine the de-greasing and rubbing processes. This will probably force some of the contaminants into the scratch marks making it even more difficult to remove them.

Once fully scuffed the parts should be rinsed, dried and should have a uniformly dull sheen. If there are any deep scratch marks still visible then you will need to remove then before painting.

Clean again with grease and wax remover.

Plastics take on static charge easily and will attract dust so applying an anti static spray will be a good idea. Once applied, try to avoid re wiping the part until you have completed the job. It is also worthwhile grounding the item which will allow any static to dissipate.

If you are spraying from a can then use a plastic specific primer which will have a flex agent in it.

From there on in treat as you would for metal.

Remember that the more care you take at the beginning the better the finish will be at the end.

If you want a show winning glassy shine then invest in some Micro Mesh rubbing cloths. But that may be another post?

Irish · Full Member Joined: Jun 12, 2007 Posts: 250

wow, great info ,thanks

What Happened to 650rider.com?

Yamaha xs650