Protect Your Plastic Parts Or Just Paint Them Over?..

As an "ex" wrangler owner I found that many of the plastic parts on any jeep make and model have or seem to have a lack of dye or pigment injected into the molds. (Ie Fenders, etc) The introduction of Krylon's new Fusion (plastic spray paint) this lead me to do some of my own testing.

After some testing on the Old 99 wrangler.. I thought I would give the 07 Commander a new look.. Masking off the step plate located on the rear bumper. I attempted to spray a light coat of the fusion paint on the step plate.

Originally my main goal was to chrome many of the accessories myself. But found that the (gold) clear coat didn't hold up on silver chrome parts as I would have hoped.

Never the less I set out to refinish the rear bumper step with the black krylon plastic paint. After two coats I was very surprised at the results. Although The step plate tuned out nicely, Will I have to refinish the step plate in a few years?.. Will the paint simply wear off? in other words.. what do I have to look forward to before I apply more paint on other plastic parts.

You can view the before and after results via:

Our JeepLife - Jeep Commander Rear Bumper Touch-up

btw. Contacted Krylon soon after, and they informed me that it was acceptable how I did this touch up. But the "promoter" would have helped. So far 4 weeks and no signs of wearing off.

as with any paint - prep is the key to longevity. with plastic even more so. rather than just taping it off & painting it you should have taken it off completely, sanded it down to make rough not smooth, gotten a good adhesion promoting primer and sprayed the entire thing. when you tape it off it leaves edges of the paint that will begin to lift and peel. krylon may advertise their paint as a "one shot no primer needed" product, but you have to keep in mind all the trim pieces are thin plastic that flex. the flexing will cause stress cracks in the paint and it will start peeling away.

Here is the problem with painting plastic. During the manufacturing process there is a substance called a " mold release agent " that is applied to the inside of the mold. This substance allows the part to pop out of the mold easily. The problem is that this substance gets transfered to the part and paint does not like it. This stuff has to be washed off properly and then an adhesion promoter needs to be applied. I had been using PPG paint systems up until 2004 and we had the worst luck with getting paint to stick to new unprimed bumper covers. All asian auto manufacturers, with the exception of Honda / Acura , ship out the new bumper covers without any kind of primer on them. They are in a raw plastic state. They must be treated properly. We switched to a paint system owned by DuPont called Standox and have not had a failure in six years. Standox's prep system uses a plastic cleaning paste in which you simply use it as a soap and wash the bumper with it. Then you spray on a coat of plastic primer, wait 20 minutes, and start spraying your basecoat ( color coat ). If you dont do this the paint will not stick, I guarantee it. If I was to paint my black plastic trim pieces, I would use the very same process. I do not trust the rattle can systems. They tend to make things sound so easy and simple, usually with less than desireable results. Now with that said, some auto manufacturers have what they refer to as " unpaintable parts ", meaning paint will not stick no matter what you do. It has something to do with the plastic material used. Some parts you may recognize would be the lower cladding pieces on the Chevrolet Avalanche. GM claims that they cant be painted, I have never tried it though. If you've ever gone to your local round track races you've seen the cars with generic white front ends. These plastic parts are unpaintable. Believe me , I've tried. The best way to paint your trim is to remove it, clean it, prime it, then paint it.

Just another reason to ditch the plastic bumpers and rockers for metal.