HOME FAQs BOOKS JOBS: Help Wanted Suggestions      you are here: Hotline/Forum => Letter 130a

---

Repairing plastic-plated headlamps and auto trim

-

I am interested in learning more about the process involved to replate / repair plastic automotive parts with chrome. What are the basic different types of technology, who supplies raw materials and training? I had a headlamp apart several years ago, which was plastic, the reflector was very similar to chrome, but looked to be a spray applied material,

who supplies this material? Is it also used for decorative purposes on plastic automotive trim? I have considerable experience in the industrial coatings field, and am considering looking into providing this service to old car enthusiasts such as myself.

T. Logan
Canada

---

November 10, 2008

Hi, T.

There are many different ways of applying a reflective look to plastic.

Addressing decorative trim first, like auto grills, tail light bezels, emblems, and the surrounds exterior to the headlamps, this is chrome plated plastic (usually ABS plastic). We offer an Introduction to Chrome Plating which will briefly explain that subject. If at all possible, try to get your hands on "Standards and Guidelines for Electroplated Plastic" although it's out of print and very hard to find.

Chrome plating on ABS is a very robust (but rather expensive) finish which can withstand temperature extremes, road salt, and a reasonable amount of abrasion.

The reflective finish inside a headlamp is not chrome plated plastic for two reasons: first, it doesn't need to be robust because it is sealed inside. Second, as bright and beautiful as chrome plating is, it is actually a poor reflector because it absorbs certain frequencies. You've probably seen how hot chrome gets in the sun; in fact, the best solar collectors are chrome plated. The finish on the reflector is probably vacuum metallized aluminum unless it is an old and horribly expensive car like a Rolls-Royce, in which case it may be rhodium plating. Good luck with the enterprise.

Regards,

Ted Mooney, P.E. finishing.com Brick, New Jersey