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 pacth 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.
Cos: The drawback to this method was if you didn’t do everything perfectly, the patch would leak, and after a period of time of water-wade and speeding rotation of tire, the patch could peal off.
Hot patching involved essentially the same procedure 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. If 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.
Cos: Actually this is the best way to repair a tire puncture, but it demands high performance of machine and technics, the tire could be deadly burned and deformed when temperature is not cintrolled precisely.