When you’re engineering an environmentally friendly metal-coating process, success relies on measuring and controlling temperature.

Mitch Curtin of Helios Coatings uses an infrared thermometer and a bead probe to monitor the fluid temperature of a soap bath solution used in the cleaning of raw wheels before the first primer process.


Known informally as "the go-to guy" at Helios Coatings Inc., Dave Summers' official title at the metalized coatings maker is manager of facility and process engineering. His sobriquet has roots in a long history of testing and tinkering with electronics to help them deliver more than intended. For instance, Summers built an FM radio while in the third grade, and he installed a digital dashboard in his 1951 Mercury -- back in 1980.

At Helios, his challenge is to maintain precise control over the proprietary process his company uses to finish car wheels and hubcaps. The core of the company's business is refinishing wheels, but automakers are eyeing the process for OEM work because of its low environmental impact and durability.

"We use green technology to do chrome-like finishes on aluminum rims," says Summers. A veteran of the powder coating industry, Summers knows how important temperature control can be when baking finishes onto temperature-sensitive parts like plastic hubcaps. Parts have to be cleaned, primed, finish coated using a vacuum metal-deposition process, and finally clear coated for protection.

"During the process, we use an infrared heater to cure the coatings," he says. "Temperature is critical, as some of the center caps that are coated will warp easily. Attempts with a stationary sensor have failed miserably." A try at curing one set of high-end rims failed when the plastic caps curled up.

Summers tested the Model 568 infrared thermometer from Fluke Corp., Everett, Wash., in the Canton, Ohio-based coating maker's lab, using it to measure the temperature of the sensitive substrates. "I really enjoyed having the opportunity to play with it. And that's what I call it -- playing with it -- because I absolutely had a blast with it."

James Solomon monitors the surface temperature of a wheel that just had a primer coat applied in the spray booth in Helios Coatings research laboratory.

The rims and caps go through an infrared curing process, then through a high-tech ultraviolet system.

"The whole idea is not to heat your aluminum above 200°C [400°F] -- you'll lose the temper in the wheel," Summers says. "There's an art to doing it without destroying the aluminum itself, so we're real careful about temperatures. We don't just throw them in a baking oven. It's all in timing, distance and intensity of the radiation."

Monitoring that precise heating process was one place where the infrared thermometer from Fluke paid off for Summers. The laboratory's experimental infrared curing setup includes a built-in thermometer. During testing though, Summers discovered that hand-holding the Fluke unit at approximately 18" from the slowly rotating parts delivered more accurate readings.

"When I found out what that 568 did, I was like, ‘holey schmoley,' this thing's like a Godsend," Summers added. "As far as the menu, it's extremely intuitive." Adjusting the emissivity for accurate readings on different materials required only a few touches on the control buttons.

Summers also experimented with the software that comes with the thermometer. "Most of the software I deal with on a daily basis is just a pain. You need a copy of ‘War and Peace' for a manual. With this, I was up and running and able to do a bake curve in 30 seconds."

A bake curve displays the rate at which parts in the finishing process are heated and cooled over time.

"Heating a clear coat too fast will yellow the finish," Summers explained. Gradual heating and cooling delivers the desired quality. PH

For more information from Fluke Corp., call (425) 446-4620 or visit www.fluke.com.

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