How to prevent tire dry rot
If you notice little cracks running spider-like along the sidewalls of the tires and running all the way to the tread, you may be experiencing a common phenomenon that occurs in stagnant cars – dry rot.
One of the most common reasons for dry rot is improper storage or infrequent use. According to an Angie's List Classic Cars member poll, only about 40 percent of classic car owners drive their classic or vintage vehicle more than once each month.
Signs of dry rot
Rubber and plastic materials naturally degrade over a period of five to six years depending on the climate, temperature and humidity, the use and storage of the vehicle, and the air pressure levels of the tires. Dry rot is indicated by hard and brittle surfaces on the tires. As the oils in the rubber begin to evaporate, the chemical bonds break down leaving a dry tire behind.
Just what causes dry rot?
The most common causes of dry rot include low inflation of the tires, storage near excessive heat and a lack of use. Constant exposure to sun can speed up the effects of dry rot upon the tires, so if your car sits for long periods of time in balmy Florida, chances are your tires will deteriorate quicker. Finally, if your tires were manufactured several years ago, they could be unwrapping, whether they’ve been on your car the whole time or not.
Is there anything I could have done?
If you have to store your vehicle for long periods of time, ideally store it in a climate-controlled garage, keep the tires inflated to the manufacturer’s recommendations, store it with boards under the tires and check the air pressure at least once a month.
That horse is out of the barn, how can I fix it now?
Dry rot can be fixed only in the early stages. Try using a water-based tire product to help seal cracks and avoid products using petrochemicals or silicone. If dry rot is advanced, the only real solution is to replace the tires.
Is it safe to drive rotted tires?
In most cases, tires with dry rot are probably not safe to drive on. Around town, you may have a little time before you need to replace the tires. Once the cracks reach the cords of the tires, the heat of long distance driving will cause the rubber to expand and the tires to actually break apart while driving.