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Chroming plastic motorcycle parts

 

To Whom it may concern,

I am interested in finding out whether plastics parts on motorcycles can be chrome plated, or if some kind of durable chrome finish other than chrome plating is available. I've been checking a lot of web sites, and they all seem to be talking about ABS plastic when it comes to chroming. What exactly is ABS plastic. I would like to chrome all of the plastic on my sport bike, but some of the articles talk about possible cracks developing in the chrome if it has to bend slightly causing the crack to propagate through the plastic.

Thank you,

Jeffrey N. Bell
- Reading, Pennsylvania, USA

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A. Virtually anything, including rocks and flowers, can be chrome plated, Jeffrey. The major issue though is usually getting enough adhesion for the application to be satisfactory.

Most of the shiny automotive grills, tail light bezels, head light surrounds, and emblems you see on automobiles are indeed ABS, that is, acrylonitrile butadiene styrene because there is an available etching protocol that will allow the metal to get a terrific "tooth" on the plastic. If you think about OEM automobiles and the need for the plating to adhere perfectly for years to plastic parts, in the extreme heat and cold, and the wear of washing, you can understand that adhesion needs to be outstanding.

There are a few other "plateable plastics" including some plating grade polypropylene and filled nylons, but in general, real electroplating will not stick sufficiently to most plastics. And chrome is a very hard and brittle material unsuited to flexing.

There are other ways to get a bright look, including vacuum metallizing (as you've seen on shiny mylar balloons and perhaps helmets), but this requires expensive vacuum application equipment. And there are metallic paints ranging from a few dollars a spray can in your hardware store (and not really looking very metallic), on up through expensive and exotic paints that really do look an awful lot like chrome. But it is hard to get adhesion to many plastics, and it's hard to keep even simple paints tightly adhered to a flexing part. Sorry; wish it were easy.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey