Preventing Tire Dry Rot
Date: Spring 2013
My dad has a classic car, and because it gets driven very little each year, the tires dry rot before he can get much tread wear on them. What could be used to protect the tires from dry rot and cracking?
Thanks for the question. I would recommend keeping the car on blocks so that there is no weight on the tires. Additionally, I would recommend that no electrical equipment (motors, switches, and other things that spark) be used around the car. The sparks generate ozone and ozone can cause rubber items such as tires, belts, and hoses to crack.
I hope this helps. Please let me know if you have more questions.
You have a tough problem. The "dry rot" and ?cracking? is caused by the reaction of the rubber and oxygen from the air. The oxygen reacts with the rubber and breaks the carbon / carbon bonds and the sulfur bonds as well. This process is enhanced by light and moisture, and is difficult to inhibit. So what are you to do? There are several options. (1) Search for some compatible "modern" tires. "Modern" tires have additives that inhibit this attack on the rubber by the oxygen.
(2) Inflate the tires with gaseous nitrogen. Flush several times with the nitrogen. Do not completely inflate the tires with nitrogen for storage. This of course, only protects the inside of the tires, but it is a start.
(3) If you have not done so, store the car on ?blocks? and remove the tires and maybe all four wheels. Store these inside. Do not leave them out exposed to the "elements". If you have the room, store the tires inside in a dark bin, e.g. in the cellar. Do not store them in an attic. That gets too hot, which accelerates degradation.
(4) The storage bin should be as ?air tight? as possible. Purge the bin with nitrogen. Store each tire in one or two heavy duty polyethylene, or polypropylene, bags. Seal the bags as well as possible. These plastics do not allow oxygen to diffuse through, and so act as a barrier.
(5) Search out other classic car buffs, and see what they do. This cannot be a problem unique to your tires.
Click here to return to the Material Science Archives
Update: November 2011