Protecting catalytic converters from theft with a metal shield

Aaron Meldrum custom-built this cat shield for a Toyota Tundra. Fabricated from 3/16-in. hardened steel, welded, and painted with high-temperature paint, the shield was installed on the vehicle using stainless steel security hardware. Images: Aaron Meldrum

Aaron Meldrum opened American Metal Fab & Welding in 2021. Ever since, the shop owner has worked on fabrication projects like signage, gates, and fire pits.

"I just fell back in love with working in the shop," said Meldrum, who had formerly worked at another shop. "At one point, I decided I wanted to open my own shop," Meldrum said.

And he has done just that, opening the shop in Spokane Valley, Wash., with friend and local shop owner Brandon Blasberg. This summer, the shop's Facebook page highlighted projects like a custom 13-ft. gate and modified containers. The page also highlighted the services the shop provides, such as CNC plasma cutting, sawing, machining, forming, tube bending, and welding.

But one type of custom fabrication project at the shop has received more attention than others this year—even from the local news. Since the start of 2022, Meldrum has designed, built, and installed more than a dozen catalytic converter shields for vehicles.

Meldrum calls them "cat shields," intended to protect catalytic converters from anyone attempting to cut off and steal the part—an increasing problem in communities across the U.S., including the Spokane area.

"Realistically what I want to do is production work, repeat parts, custom gates, some artistic stuff. But right now, there was kind of that need, so we’ve been able to do that for customers," said Meldrum.

A catalytic converter's primary function is to convert a vehicle's toxic exhaust into less-damaging pollutants. The exhaust device—located on the vehicle's underside between the engine and the muffler—is made from platinum, palladium, and/or rhodium, which are increasingly valuable metals.

The National Insurance Crime Bureau (NICB) reported 1,298 catalytic converter thefts in 2018, 3,389 thefts in 2019, and 14,433 in 2020. The organization said there is a "clear connection between times of crisis, limited resources, and disruption of the supply chain that drives investors towards these precious metals."

Public information company BeenVerified analyzed the NICB theft data and reported four times as many catalytic converter thefts in 2021 versus 2020. BeenVerified further estimated catalytic converter thefts from January through April 2022 were 33% higher compared to the same time period in 2021.

According to the report, Washington state is one of the hotspots for these thefts. Washington ranked third among states in 2021 for total number of catalytic converter thefts (4,252) and first in the number of thefts per 100,000 registered vehicles (148).

Meldrum opened American Metal Fab & Welding in 2021 in Spokane Valley, Wash.

Meldrum has welded on and off since he was 17, and this ultimately led to work on cars. Welding and cars are part of Meldrum. He learned how to TIG weld working at an auto engine shop. His interest in automobiles includes a decades-long fascination with Volkswagen Beetles and building high-performance engines for them.

A former acquaintance of his knew Meldrum understood cars very well. She had a question for him: Could he fabricate something to prevent thieves from stealing catalytic converters? Box vans at her employer had become targets.

His solution was the cat shield. The cage-like structure is custom fabricated from 3/16-in. hardened steel, welded, painted with high-temperature paint, and installed using stainless steel security hardware that can be removed when needed by the customer.

"They entrap the catalytic converter. Even if [the converter] was cut, it can't be pulled out," Meldrum said.

"When we plasma-cut the exterior as well as the holes, it really hardens that metal. If someone decides to try to cut through, their blades or saws will likely get destroyed," he added.

The size of the shield will depend on the space available surrounding the converter, the converter's size, if the vehicle has multiple converters, and the make and model.

Meldrum cuts vents and slots into the shields to allow airflow around the converter.

"Heat management is a critical factor because they’re air-cooled vehicles. Just knowing that or keeping that in the back of my mind when putting shields around these cats to ensure there's plenty of airflow, that was a real conscious effort" to limit any overheating, he said.

He's installed these shields on a Toyota Tacoma, Toyota 4Runner, and Honda Element, among others. The plasma cutting software he uses allows him to save and store designs on his shields, making it easier for him if a customer brings in a make and model he's dealt with before.

"This is one of those processes we do where the more we do it, the quicker it will be to get it done," Meldrum said.

Meldrum has designed and fabricated more than a dozen catalytic converter shields for customers in 2022. He hopes the welded steel structure will make it difficult or impossible for thieves to cut the exhaust part and bring customers a sense of security.

The cat shields start at $400 but increase depending on the size and scope of the project. Meldrum cautioned that "most often, anything that's preventive, insurance won't pay" for the purchase and installation.

Practically everyone who has inquired about the shields has already fallen victim to this type of theft, Meldrum said. One customer had his vehicle targeted three times. Customers inquiring and requesting a cat shield may have already gone through the costly replacement of the car part and paid for some or all of the cost, depending on their insurance coverage.

His advice to people worried about their catalytic converters? Think proactively—get a quote on an anti-theft device and decide if it is the right choice. "Protect yourself now or pay for a new catalytic converter later," he said.

Reacting to the large number of thefts, Washington implemented a new, statewide law in July that requires scrap metal businesses buying a catalytic converter that was removed from a vehicle to document whether that vehicle is registered in the seller's name. The law also restricts some cash transactions if the seller does not provide an address and photo ID.

"What we’re actually starting to see is less converter thefts happen because it's not as easy as just cutting them off and getting a payout, which I'm totally fine with," Meldrum said.

Meldrum said he is OK if he loses cat shield business—after all, he didn't start American Metal Fab & Welding with anti-theft device projects in mind. A pivot away from the shields would refocus all his efforts on the types of fabrication projects he sought when opening the shop.

"Again, I’d rather be doing things that people want and not what people need," he said.

American Metal Fab & Welding has worked on other fabrication projects since its opening, including custom gates.