Doug Therrien doesn't have any delusions about flatproofing OTR tires. "It's really boring to do," says the vice president of Central Tire Co. in Sanford, Maine.
But Therrien gladly puts up with the monotony because of the profit that flatproofing generates. In the nine months since Central Tire started flatproofing OTR tires in-house, the service has grown to comprise 10% to 15% of the dealership's total commercial tire business.
What's needed
Central Tire services commercial tire accounts throughout New England. It has offered tire flatproofing for several years, but always through a third party. Pick-up, delivery and scheduling problems eventually made doing it that way a hassle, according to Therrien. So Central Tire brought the service in-house last July.
Start-up required some investment. Therrien paid $10,000 for a fill dispenser, or pump, and $2,000 for a used forklift to transport filled tires. Long-time supplier Galaxy Tire & Wheel Co. helped guide him through the equipment buying process.
The dealership also cleared a dedicated area for the service -- in this case, a room it keeps at a constant temperature of 70 degrees, which is critical when using polyurethane fill. "Down south, temperature isn't a big deal," says Therrien, "but it is in New England, where temperatures can get down to 20 below."
Central Tire then set up the pump with help from flatproofing material manufacturer Arnco. Representatives from Arnco showed Therrien how to use the machine and within an hour, the system was running.
Process takes time
It didn't take long for Therrien and other employees to get the process down. Here's how they typically flatproof a tire with polyurethane fill.
1. Inspect the tire and rim. "They have to hold air. If they don't hold air, they won't hold fill."
2. Coat the rim with a thin layer of mounting paste so the foam will peel off more easily if the tire has to be cut open at a later date.
3. Mount the tire and fill it with air to the manufacturer's recommended psi level.
4. Let the tire sit for 24 hours "so it will stretch." The tire is then ready for filling.
5. Screw the fill tube connected to the pump onto the tire's valve stem.
6. Poke a hole in the top of the tire with a drill and start bleeding air out.
7. Turn the pump on and begin filling while air is draining out to avoid the development of air pockets. The pump itself mixes two chemical components, isocyanate and polyol, at equal volumes, which creates the end fill material that's pushed into the tire via the valve stem.
Fill time varies by tire size, according to Therrien. He says it takes about 30 minutes to fill a 14x24 grader tire. "When foam comes out of the top of the tire, you know it's full."
8. Turn off the pump and seal the air hole with a roofing nail or screw.
9. Turn the pump back on and pressurize the filled tire while monitoring psi levels using an air pressure gauge built into the hose. "A 60-pound tire will take 58 pounds." Don't pressurize to the maximum psi level, warns Therrien. Over-pressurization can cause tires to split due to carcass strain.
10. Once the tire has been pressurized, lay it flat on a pallet in a warm, dry place and let it cure for a day. "Then it's ready to go."
Don't hurry through the process or skip steps, says Therrien. "You get some customers who try to rush you, but we do it right the first time."
Time savings
Therrien quickly found out that flatproofing tires at his own facility would be a money-maker. It costs Central Tire 81 cents a pound to fill a tire, including materials. The dealership charges wholesale customers, including fellow tire dealers, $1 a pound. "I just had a client from Portland, Maine, who wanted two tires filled," he says. "Each tire took 1,000 pounds of fill." Central Tire charges retail customers up to $1.30 a pound.
Therrien schedules most of the dealership's flatproofing activities on Thursdays. "If we fill on Thursday, the tire will cure over the weekend and customers will have it by Monday."
Most of Central Tire's flatproofing customers are end users like equipment rental companies. The dealership services four rental companies, "and one gave us more than $80,000 in business last year. Tire dealers who aren't handling equipment rental companies are crazy. There are so many of them and they're dying for quality service."
In most cases, price is secondary for equipment rental agencies. "Some of these guys are renting equipment for $400 an hour; they can't afford to have downtime."
Therrien and his staff have flatproofed tires of all sizes, from 4.10x4 lawn mower tires to 26.5x25 tires mounted on a CAT 972 loader. The latter job was done on-site at a construction yard. "I took the pump in the back of my pickup truck." It took Therrien and his brother a full day to demount and fill the tire, plus another two days for the newly flatproofed tire to cure on the spot ("It was during the summer").
Central Tire charged $6,000, which the customer gladly paid. Therrien doesn't advertise flatproofing but a growing number of customers are asking for the service thanks to word-of-mouth referrals. Some clients who have turned down proposals from Central Tire in the past now eagerly seek the dealership's help. "We have something else to offer them."
Making it work
Dealers have been using polyurethane fill to flatproof OTR tires since the early 1970s, according to Arnco President Larry Carapellotti. Prior to that, the dominant fill material was Permafoam, a natural latex foam material that is still used.
Initial applications for polyurethane fill included underground mines, where the technology "was immediately recognized" as a viable alternative. Polyurethane has since gained widespread acceptance to the point where it now comprises more than 95% of the flatproof material market, says Carapellotti.
"In some applications like a landfill or metal recycling facility, where flats may occur on an hourly basis, it's a no-brainer. You can take any pneumatic tire and virtually turn it into a solid tire" via flatproofing while maintaining the original unit's load deflection characteristics, he says.
"A lot of tire dealers have a love-hate relationship with fill. They love it because it's profitable. But in another respect, they hate it because they lose after-sales profit. Basically, a filled tire is good until you (wear down the tire tread)."
Donald B. Rice Tire Co. started flatproofing skid steer tires 12 years ago out of its commercial facility in Frederick, Md. "Landscapers and small contractors were experiencing a lot of flats and were asking for it," says Jim Hammond, vice president of sales and marketing for the company's Commercial Division.
The company now flatproofs tires at two additional locations, in Baltimore, Md., and Haymarket, Va. It buys tire fill by the tote, which is a "large container that's four feet tall by four feet wide. We go through a lot of totes in a year's time."
Flatproofing comes with its own set of challenges, according to Hammond. "It's labor-intensive to cut off an old (already-filled) tire."
The key to making the service work is finding out how customers plan to use their filled tires, he says. "The skid steer, which is the most commonly filled tire, is such a multi-purpose piece of equipment. What you use it for might be different than what I use it for. It's our job to determine what the customer needs."
Mind the temperature: Warmer proves better when working with polyurethane
Polyurethane tire fill always should be processed at room temperature or higher, says Arnco President Larry Carapellotti. "For every 10 degrees you go down in temperature, you double the time it takes the tire to cure. If you take the temperature down to 50 degrees, for example, it will never cure properly."
Warmer fill also pumps through the valve stem faster. "Pumping warm material into a cool tire is better than pumping cool material into a hot tire," since tires have insulating properties, he adds.
