Rick Fennell rust proofs a truck at his shop in Summit Township.

Road salt has been used for many years to melt snow and ice to make streets drivable in the winter.

It also causes vehicles to rust, but liquid brine chemicals used in recent years to treat roads and prevent ice from forming are more corrosive and eat up the undercarriages of vehicles.

“The rust problem has gotten out of hand,” said Rick Fennell, who has owned Rick Fennell Rustproofing in Summit Township for 45 years. “Heavy structural steel rusts faster due to anti-icing pretreatment. It doesn't wash away. The road surface is porous and it settles in there. The rain and tires churn it up.”

Once the brine finds its way on to a vehicle, freezing and thawing help it penetrate seams and welds, he said.

Freezing and thawing allows condensation that carries the chemical to pull on spot welds and seams on body panels. The condensation gets behind welds and seams and slowly causes rust.

“The damage is microscopic, but that's how rust starts,” Fennell said. “Every time it gets wet, it accelerates.”

Car washes can't remove the brine from tight spaces and can worsen the problem by spreading the chemical around the vehicle, he said.

Most rust proofing products are made from paraffin and aren't effective, which led Fennell to apply something he learned from working on heavy equipment to make his own rust proofing and undercoating products.

“Things that are coated in grease and oil don't rust,” he said.

Fennell's products are made from oil and grease. He said they don't harden and crack and they penetrate the tight places where rust tends to start.

“The characteristics and effects we see from grease and oil for protection and coverage is the best I've ever seen,” Fennell said.

He said he applies the products, which are sold in stores, to all metal parts of the undercarriage and inside door panels. Those parts include brake lines and fuel lines.

“Brake lines didn't rust 40 years ago,” Fennell said.

Brine also cause pitting on alloy wheels, but their impact on aluminum body panels isn't known yet.

“Only time will tell,” Fennell said. “I do many aluminum bodies.”

He said he works on vehicles by washing and preparing them before applying his products.

“We can clean areas that can't be done at a car wash. It won't put back the metal that's gone, but it will slow it down and in some cases stop the rusting process on most vehicles,” Fennell said.

He said painting techniques at auto factories are much better now than they were in the past and that prevents a lot of body panel rusting problems.

However rust proofing isn't a priority for manufacturers because rust is not a major problem in most of the country, he said.