Q: What Should I Do If My Tire Has a Nail In It?

Getting a nail or other foreign object stuck in your tire can be irritating. Most of the time we do not notice that a puncture has occurred until we come out to the vehicle and the tire is flat. There are any number of sharp and rigid objects that you can run over that can penetrate into the tire causing the air to leak out slowly, or in some cases very rapidly. If you get a puncture in your tire it is important to get it repaired right away to prevent any damage to the tire. Some punctures cannot be repaired, so knowing the location of the puncture can assist you in knowing if the tire is repairable or if it will need to be replaced.

The location and size of the puncture will determine if it can be repaired. Just about any puncture in the tread area of the tire can be repaired, as long as it is not too large. The general rule is that any puncture larger than about ¼”-½” should not be repaired, though this can vary by tire manufacturer. If you pick up a nail in the sidewall of the tire then many times that cannot be repaired. If the puncture happens in the tread area that wraps slightly onto the sidewall then it is typically repairable. If the puncture is lower onto the sidewall and it more than ¼” from the tread then it cannot be safely repaired.

There are many ways to repair a tire when it has a puncture, but there is only one true way to repair a tire which will protect the tire for a long period of time. For a temporary repair, the tire can be plugged from the outside. There are plug kits that are sold at auto parts stores, and that many emergency roadside companies carry, that can be used to seal the puncture by inserting a plug into the hole in the tire. These are good for a temporary repair and are not recommended for long term use. There are products called fix-a-flat that can be used on a temporary basis which can assist in getting the tire to hold air long enough to get it professionally repaired. These chemicals should not be left in the tire as they will damage the tire over time.

The only correct way to repair a tire is with a patch from the inside of the tire. This needs to be done at a shop that can remove the tire from the rim. With the tire removed, the shop will inspect the inner liner of the tire to make sure that it was not overly damaged by the puncture. If the tire is repairable, the puncture hole will be cleaned up with a small drill-type bit that will remove any imperfections and sharp material from the steel belts of the tire. Once that is cleaned out, the inner liner of the tire will be ground down to smooth it out and make the surface suitable to stick the patch to. Once the tire is prepared the patch can be installed. The best type of patch is called a uni-seal or plug-patch. What this type of patch does is it inserts a rubber plug into the hole to protect the tire from moisture, and patches it on the inside to hold the air in the tire. Before the patch is installed a special type of rubber cement will be put on the tire which the patch will stick to. Once the patch is properly installed it can be covered with a special coating that seals it further and protects it from moisture. Any excessive plug material will also be removed from the outside of the tire. Once the patch is complete and dry the tire will be reinstalled and the patch checked for leaks.

If you get a nail in your tire it is important that you have it repaired as soon as you can. The longer you drive with a puncture, the higher the chances that the tire will be damaged beyond repair. You should also keep in mind that repairing many types of tires, especially high performance tires, will affect their speed rating. Once the tire has a patch in it the tire will no longer be rated at the same speed as it previously was. If the vehicle is used for any type of racing you should check with the tire manufacturer to see how your tire is affected.