We have several people that visit Texas Tire Sales asking us to “plug” a hole in their tire. We patch tires at Texas Tire Sales but we do not “plug” tires at either of our Tire shops. I have never plugged a tire on any of my personal vehicles. I personally don’t feel that it is the safest or most effective procedure for repairing a leaking or damaged tire.
Yes, plugging a tire is cheaper than patching by about 5 or 6 dollars and that is likely the main reason many people request plugs. The old adage, “You get what you pay for” may speak volumes in this particular comparison of plugs vs patches as plugging a tire may not be less expensive in the long haul.
I do know that we deal with the end result of a failed tire plug on almost a daily basis – it usually involves a tow truck, a destroyed tire and sometimes a ruined rim.
What is a Tire Plug.
A tire plug is a sticky, expandable object that gets stuffed in a hole in the tire from the outside and is wedged in until the air stops leaking out. The plug should easily stay intact well enough to re-inflate the tire and get safely to a repair shop. Of course, there are people who swear by the plug and have told me in no uncertain terms “that plug will outlast my wife”. I typically don’t argue with these folks or question their relationship with their wife nor do I see any benefit in telling them that their confidence and experience with tire plugs contradicts what we see every day in our repair shops. We simply let them know that we are tire professionals and will not do a substandard repair when there is a better option.
In all honesty, people bring us their tires when something has gone wrong. They don’t stop by the store to show us how well their tires are wearing or to show us that they don’t have a flat. Therefore, I have no statistical data that confirms my opinion on tire plug success or failure.
Having been in the tire business for over 20 years, I do know a few things about the properties of tires, though. Speed causes friction. Friction causes heat. Heat causes expansion. Tires expand as they heat up. A tire plug made of a different compound than the tire rubber expands at a different rate than the tire. You will have to rely on your stuffing skills to be sure you stuffed the plug in the hole properly and with enough sticky material that the plug will continue to hold when the tire heats up and expands under increased heat caused by increased speed/friction.
Speed means you are going fast, which means you are taking a chance on a failure while at that higher rate of speed. This is where the above described tire/wheel/vehicle damage comes in. As a tire cools off, it contracts. Now you get to hope that the tire is contracting at a greater rate than the plug material so you are not left with a leak and subsequently sitting roadside waiting for a tow truck.
I wish I had a nickel for all of the times I’ve seen a plug sticking through the inside of a tire with a hole right next to it. The plug installer was apparently unable to insert the plug in the exact path of the object that originally punctured the tire, so he punctured the tire again and made different hole as he rammed the plug through the tire tread.
Plugging a tire can trap air between the layers of tread. When the plug is dipped into the glue and inserted into the hole, the plug glues itself to every layer it passes through. As the tire heats up, the air between the layers begins to heat up and expand. The air has no place to go, so as it expands, it causes the tread to separate from the rest of the tire. If the tire was patched, the patch prevents any air from inside the tire from escaping, but allows any air trapped between the layers to escape out of the entrance hole in the outer tread area.
The same thing happens when the plug is not inserted exactly into the path the puncture occurred in. The air inside the tire tries to exit using the hole that was missed. As the air moves towards the outside of the tread, it becomes blocked by the plug that was inserted into the outer hole. Again, the air is between the layers of the tire, it gets hot, expands and causes a tread separation.
What is a radial patch?
The fact is, we now have a better option to plugging tires and it’s called a radial patch. As I stated above, my professional “tire guy” opinion and experience dictates that any tire repair done without removing the tire from the wheel is improper. Without inspecting the inside of the tire for hidden damage comes the risk of returning a weakened tire to service. That is not to say that in some cases a plug wouldn’t serve as a temporary low speed solution. For example, If a tire is punctured while off-road in the middle of nowhere and a spare tire isn’t available, you might use a plug but, that plug should be replaced with a radial tire patch as soon as possible.
Radial patches are specifically designed to repair radial tires which comprises most of the tires on the road today. Radial patches are self-vulcanizing. That is to say after they heat up from driving, they “melt” into the tire and become one piece. Patching a tire with a radial patch can take about 20 to 30 minutes while installing a plug takes only a few minutes and usually can be done while the tire is still on the car.
Don’t just take our word for it.
The Rubber Manufacturers Association (RMA), the national trade association for tire manufacturers that make tires in the U.S. refers to a tire industry study which showed that nearly 88 percent of tire repairs are performed improperly. They also suggest that any tire repair done without removing the tire to inspect and determine the extent of the damage is an improper repair and could pose a safety hazard and could also affect the manufacturer’s warranty. The RMA also offers Tire Dealers and auto repair shops detailed wall charts which show , in detail a proper tire repair. Here is a list of criteria to perform a proper tire repair according to the RMA:
- Repairs are limited to the tread area only.
- Puncture injury cannot be greater than 1/4 inch (6mm) in diameter.
- Repairs must be performed by removing the tire from the wheel in order to perform a complete inspection to assess all damage that may be present.
- Repairs may NOT overlap.
- A rubber stem or plug, must be applied to fill the puncture injury and a patch must be applied to seal the inner liner. A common repair unit is a one-piece unit with a stem and a patch portion. A Plug by itself is an unacceptable tire repair.
At Texas Tire Sales, we charge $10.00 to patch tire in the fashion approved by the RMA. If you insist on having your tire plugged in order to save a few bucks, we will be unable to assist you.