Plugging a tire will damage it because air will get between the inner and outer layer and cause a rupture.
As long as the leak is not in the side wall, plugging a tire works quite well for small leaks such as those caused by a nail. I have had many a tire plugged with no problems.
According to an independent tire place I have been going to for years (a business so honest they even turned down a job because the customer did not need the service) only patch tires, not plug them, for the reason I stated.
Jeanette Isabelle
A patch or plug won't help on sidewall (or near sidewall) punctures due to the lateral stresses involved. The plug cannot transfer the stresses and all glues used for patching will eventually fail due to the lateral stresses. This sets up a situation that can easily lead to a catastrophic tire failure. Fix a Flat or equivalents are also not going to help this situation and should not be used.
Plugs are part of the NHTSA recommended permanent repair procedure for tread punctures and great for a temporary fix (temporary being loosely defined). The design of modern tires means the lateral stresses are carried by the "belts" so all the plug needs to do is seal the hole to prevent or reduce pressure loss. From a physics point of view this is exactly what Fix a Flat etc. will do though the plug is a much better solution since it has actual friction working for it in addition to bonds from polymers/glues. It is recommended that a patch be installed on the inside of the tire in addition to the plug, usually within a few weeks so you have some time to schedule the repair instead of treating it like an emergency. Many consider patching a properly plugged tire to be like wearing belts and suspenders - it goes under the can't hurt / might help philosophy so prevalent today.
Fix a flat etc. are popular because they require little to no skill or knowledge to use. The trade off for this convenience is that you need to get directly to a tire shop or service station and get the tire cleaned up and properly repaired. A proper repair should include both a plug and a patch.
I was unable to locate any reported incidents of a correctly plugged (and not patched) tire rupturing in the manner described above (or in any other fashion). There are several "hearsay" reports of this type of failure but I was unable to find a formal incident report documenting this. Apparently there are laws about this but again, these apply to proper repairs (as sold by tire shops etc.) and not "temporary" repairs.
Plugging is generally not considered sufficient for "permanent repair" for highly worn or some of the lower profile tires that are currently popular. In some areas plugs are not a legal permanent repair for commercial tires.
-Eric
Previous Topic
Index
