Tire Sealants
The jury's still out on the effectiveness and safety of sealants, but some may be worth further investigation.
Evan Lockridge
Contributing Editor
Sometimes, trusting equipment to drivers on the road is like trusting kids with expensive toys. Some kids take great care of their toys and put them up each night before going to bed. Others leave them lying around in the yard or put their G.I. Joe in the microwave.
When it comes to tires, you want your drivers to be like the good kid – keeping a check on air pressure and getting any tire problems attended to promptly. But most fleets have the bad kids out there, too – checking pressure with a tire billy, if at all, and running flat tires until they're too damaged for repair or retread.
There are products out there that some say can help. Tire sealants are products you can purchase to seal small punctures in the crown area of your tires.
Two Kinds Of Sealant
One kind is used as a preventive measure. These are put inside the tire before it's mounted, forming a coating that sticks to the inner liner.
The other type of sealant is used only for emergency repairs. This is for when a driver is stranded on the side of the road and needs a way to get back on the road – at least far enough to get a tire properly repaired.
There are a number of preventive tire sealants on the market. The makers claim that if you get a small puncture in the tire – usually no more than a quarter-inch in diameter – the sealant will perform its task and you can keep rolling along. These products also claim to minimize the usual air loss that occurs over time, leading to better air pressure maintenance, improved fuel economy and less wear.
Some also say their sealant can balance a tire, thus reducing vibration, hopping or skipping as the tire goes down the road.
The problem is, there is no general consensus about the use and effectiveness of preventive tire sealants. You won't find a single truck tire manufacturer that gives them a thumbs up – but most don't give thumbs down, either.
"We have seen very few issues with any of the products in terms of harming the tire or harming the inner liner of the product," says John Cooney of Yokohama Tires. However, he says, "Our official stance is commercial tires – because of their life cycle – need to be repaired properly, and that most punctures need to be repaired with a patch and plug in order to ensure the casing integrity over time."
Other tire makers, including Bridgestone/Firestone, Michelin, Goodyear and others, have similar opinions. If it's determined a tire sealant has harmed your tire, they caution, most likely your warranty will be voided. They also advise checking with the tire sealant manufacturer to make sure it's safe for your tires – although that seems almost like walking into the barber shop and asking if you need a haircut.
Peggy Fisher, an independent expert in the field of commercial tires for more than 25 years, has stronger feelings. Aftermarket tire sealants, she says, come with a host of ancillary problems.
"When they fill a puncture and stop a leak, the cords in the filled hole rust, and the injury grows over time," she says. "As a result, a much larger repair has to be made when the tire is finally demounted for retreading or repair."
Not A Permanent Solution
One thing most people do agree on is that tire sealants are not a permanent solution and are not a proper substitute for an off-wheel repair. The Technology and Maintenance Council's Recommended Practice on punctures advises removing the tire from the wheel, inspecting and repairing. There are also concerns that tire sealants can interfere with retreading of truck tires.
At least one tire sealant manufacturer recognizes such misgivings. Mark Farkhan, president of Inovex Industries, which makes the Ride-On Tire Protection System, says tire sealants – especially those used for emergencies – have problems that are well documented. This, he says, has caused preventive sealants to be regarded similarly. He says too many fleets have used tire sealants and suffered problems such as rusted or pitted rims, tires rejected by retreaders or failures on the road.
"However, we have worked with some of the nation's largest commercial tire dealers and given them proof of how our product works, and addressed their concerns," he says. Like tire experts, he points out that "no tire sealant is a permanent repair for a tire."
Farkhan adds that many preventive tire sealants, such as Ride-On, are made with corrosion inhibitors to combat the problem of tire interiors being exposed to moisture. How well each product accomplishes this challenge varies, of course. It's crucial that any sealant be removed before a tire is retreaded, he says, noting Ride-On is water soluble, can be cleaned out easily, and won't mask tire injuries when a casing goes through the inspection process before being retreaded.
While opinions on preventive tire sealants vary, that's not the case with a sister product – emergency tire sealants. Every tire expert contacted said these products are to be avoided. They are better suited for passenger vehicle use only, though some even question their use for that. Because these products often contain flammable ingredients, they can make a tire dangerous. Some retreaders will refuse to retread a tire if they know it's been treated with an emergency tire sealant.
While most fleets avoid their use, drivers may be more likely to use them. It's not uncommon to find them in truckstops.
One tire industry official, who says he "hates the stuff," noted there may be an acceptable use – but only if a driver finds himself just a few miles from a tire repair shop. He says it may actually be better to use an emergency tire sealant rather than trying to limp in on a flat. That's because running with a flat will likely cause permanent damage to the tire. The key to making this work is when you get to the repair shop, have the tire dismounted, thoroughly cleaned and inspected, and then get it properly repaired by a tire technician.
So overall, emergency tire sealants get a thumbs-down. Whether you should use preventive tire sealants is not so clear-cut. If you're enticed by the promises of helping your tires maintain air pressure, you might be better served to set up a program to make sure tires are checked regularly with a gauge and then keep records.
You may even want to consider a tire pressure monitoring system or tire inflation system. These can either alert drivers to low tire pressure or can add more air to tires automatically when needed.
However, if you still want to give such preventive products a try, err on the side of caution, advises Fisher.
"Any fleet inclined to use aftermarket tire sealants should first test the product on a few vehicles, as well as placing a wheel in a tub of the stuff to see if it attacks the wheel," she says. "They should also see how difficult it is to remove from a tire and demand to see the Material Safety Data Sheets to determine its proper disposal before committing the whole fleet to these products."
