Every few years a report will emerge claiming that self-healing paint is around the corner – that, in the not-so-distant future, every car scratch and ding will somehow repair itself. That hasn't happened, and it isn't going to happen any time soon.
Sure, there's Nissan's Scratch Shield technology, which is marketed as a self-repairing paint. It's a "highly elastic resin" coating that bounces back to its initial state after impact.
However, "the paint does not self-repair if scratches are deep enough to sever the bonds within the clearcoat or if the clearcoat has been peeled off," the company warns. In other words, once you get down to the actual colour layer, or deep enough through the clearcoat layer that protects it, you're as screwed as ever.
So, no, there's still no truly self-healing automotive paint.
The world of automotive pigments and coatings is one that seems slow to innovate, at least in terms of the flashy products that Silicon Valley startups typically use as today's innovation gauge. But there are different types of innovation.
If you look through junkyards, says Paul Lamberty, technical manager for BASF Coatings in North America, a pigments and coatings supplier, you'll notice something impressive.
"The coatings are actually outliving the useful life of the vehicle," he says. Cars don't rust like they used to. Buy a vehicle today, and it'll probably stay nice for a long time.
It's a subtle change – one lacking the "wow" of self-healing paint – but an important change.
Recent innovations have improved the pretreat process – so-called high-throw techniques used to more evenly build up the car's corrosion-resisting electricoat in areas that are recessed and hidden and hard for the coating to reach.
Tom Bjelica, Chrysler's senior manager of paint process, materials and quality, says that applying more sealer on the underbody and hems of Chrysler vehicles has helped reduce corrosion and rust. Combined with the application of better, harder clearcoats, vehicle coatings and pigments are more closely matching the lifespan of the vehicles themselves.
"Cars that are five to 10 years old – I'm sure you've seen on the road some of these things with very bad corrosion issues on them that we won't have moving forward," Bjelica says.
Most vehicles made within the past five years are using at least some or all of the aforementioned techniques to better keep corrosion and rust away.
But mars (distortion of coating material) and scratches (removal of coating material) are inevitable, and so the self-healing paint trope never seems to die.
A few years back, for example, Autonomic Materials Inc. was widely cited in scientific articles about developments in self-repairing coatings and pigments for its "micro-encapsulated delivery of healing agent" – microscopic capsules embedded within a coating that rupture when the coating becomes damaged, flowing healing agent into the affected area.
Magnus Andersson, vice-president of business development at the company, says that his company's product is a functional fix, not an aesthetic fix.
While it could conceivably protect a car's metal in the event of a deep scratch, it wouldn't also restore the car's colour and coating to its initial state.
"If I reverse my truck into my dumpster, it would be awesome if the metal just re-aligned itself, and the coating fixed itself, and I just moved on," Andersson says. "But there's that little thing of reality involved there that really puts the limit on it. Our technology is the first step to making that coating last longer."
But two of North America's Big Three automotive manufacturers aren't optimistic that self-healing technologies will be viable on a mass-market, consumer scale any time soon.
"We don't see the value in it at this time, at least where the technology is," says Timothy Weingartz, manager of paint materials and strategy at Ford.
Bjelica echoes Weingartz's sentiment. He doesn't see self-healing technology as a big player in the foreseeable future. The coatings tend to be expensive, largely unproven, and not feasible at high volumes.
"The focus has been more on improving the scratch resistance of the more typical clearcoats," Bjelica says.
"So avoiding the scratches versus letting a scratch happen and then being able to eliminate it via this reflowing or self-healing paint."
If you have questions about driving or car maintenance, please contact our experts at globedrive@globeandmail.com.
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