MIDLAND, Mich. (AP) — The garage at Circle K Service in Midland maintains the fleet of vehicles at nearby Dow Chemical Co., but a group of mechanics there has an unusual side job: building fire trucks.

"We do what they call component manufacturing," said Rodney Kloha, executive vice president of Circle K Service, 4300 James Savage.

"We schedule and order all of the parts and then assemble them here."

Circle K Service got into the fire truck business about six years ago after spending several years selling trucks for the W.S. Darley company.

"They needed a little help completing some orders, so we assisted," Kloha said. "That led up to doing some of our own."

Thousands of parts go into each truck, from the mechanical components to the wiring to the decals on the body.

According to Kloha, a tanker truck can take 10 months to build, from signing the contract to handing over the keys. A larger engine can take a year or more.

"The process is a lot like building a house," Kloha said. "You have to start with the foundation, and then can move to the walls and then trim it out with all the bells and whistles. Some of that time is waiting for parts to come in."

The trucks are built on either a commercial or custom chassis, and can be tailored specifically to a department's needs. Unless the department commissioning a truck requests otherwise, Circle K builds their truck bodies out of polypropylene — a hard plastic — instead of stainless steel.

"We prefer to use that because it doesn't rust or rot," Kloha said. "It really stands up to the test of time. We're building trucks to last for 25 or 30 years."

In the five years that Circle K has been in the business, they've built 15 trucks for departments all over Michigan and surrounding states. Locally, Circle K has built trucks for Flint and Frankenlust townships, and the city of Midland.

Only about 1,500 fire trucks are built nationwide in a year.

Nearly a quarter of Circle K's 20-person staff is dedicated to fire truck building and maintenance, and Kloha said there is more than enough to keep them busy.

"There are times when we have two or three trucks in here at one time, others when we're not working on a new truck at all," he said. "But all of the guys can be shifted to work on something else if we're slow. That's the great thing about being small."