Question: Tire Repair Patch vs Plug
When I first began driving in the late 1950's, if you got a nail in your tire the only way to fix it was with a "plug" which would be inserted moments after removing the nail. As radials became more prevalent, dismounting the tire and applying a patch on the inside was apparently the preferred method of repair.
Now I notice that the plug repair technique is making a comeback and in many instances is the preferred method. Please comment about the pros and cons of each method as it applies to today's steel belted radials.
Answer: Patch or Plug?
In the old days, plugs were used because they were quick and reliable. If the injury to your tire was a simple nail, a tire could be repaired in no time. If the tire was cut, then patching was preferred to completely seal the odd shaped hole.
Then when radial tires came out it was found that plugs would warp the tire and make them ride differently. That's when patches became the preferred method of repairing a tire. There were two kinds of patches, cold and hot.
Cold Patches for Tires
The cold patch required buffing the inside of the tire and applying a cement. Then the correct sized patch was placed over the injury and a special tool was used to "stitch" the patch to the tire. I don't mean stitching in the sense it was sewn on, but that this special tool was rolled over the patch until it was sealed against the tire. The drawback to this method was if you didn't do everything perfectly, the patch would leak.
Hot Patching for Tires
Hot patching involved essentially the same procedure as cold patching except the patch was heated and melted to the inside of the tire. There was a special heating clamp that went on the tire to do this. It usually took about 15 minutes to heat the patch to the tire. The advantage of this method was that the tire and patch become one piece.
Plugs for Radial Tires
Now we have plugs that are designed to repair radial tires and are self-vulcanizing. That is to say, after they heat up from driving, they "melt" into the tire and become one piece. This is again the preferred method because it is much faster to do. If a tire was cut then patching is the best way to go, as it was in the old days. One caution is never to attempt to plug a sidewall. The NHSTA says that punctures to the sidewall should not be repaired.
Patching a tire can take about 30 minutes and installing a plug takes a few minutes and usually can be done while the tire is still on the car. One caution is that the NHSTA says tires must be removed from the rim to be properly inspected before being plugged and patched. Patching a tire can cost $10.00 to $15.00 and plugging can cost as little as $2.00 but usually $5.00.
The NHSTA says the proper repair for a punctured tire requires a plug for the hole and patch for the area inside the tire that surrounds the puncture hole.