TIRE CLINIC
from the March/April 2006 issue of Today's Tire Industry |
|
Q:
We are curing rubber in a concave shape that is about 1/16 inch thick at the edges and 1/4 inch thick at the center and we have a problem with porosity at the center. What can cause this?
A:
Your problem is most likely insufficient pressure or lack of material in the center where the rubber is 1/4 inch thick. The lack of rubber would also cause porosity and it could also mean that you are releasing the pressure before the rubber in the center area is cured. First, add curing time or temperature and see if this corrects the problem. If not, increase the amount of material in the center.
Q: We are sometimes concerned that our supply of rubber solvent could be contaminated. How do we check it?
A: The best way to check solvent is to send it to a lab. But before you send it, put a few drops on a white piece of typing paper and wave the paper around in the air for about ten to fifteen seconds. The spots should completely disappear. If they don’t, you probably have a problem. It is always important to check a new supply of solvent.
Q: I constantly see tire repair technicians mixing repair materials and cements without any failure in the finished repair. Why is the industry so insistent on using the same cement as the repair material when repairing tires?
A: The repair material manufacturers are constantly doing research on these products and could make a change in the bonding gums or cements that may not work with another company’s repair materials or cement. What works today may not work with the next shipment when manufacturers are mixed.
Q: Is it risky to wash your hands with solvent to remove grease or dirt?
A: It can be dangerous and it can be more dangerous for some people more so than others. There are a lot of excellent hand cleaners that are safe and leave your hands smooth, soft, and smelling good.
Q: Are there any paints that protect a tire from weather checking and ozone?
A: Most of the protection from weather checking in tires comes from antioxidants and antiozonants that are mixed with the rubber when the tires are manufactured. A few companies have developed paints to protect tires, but I don’t know how well the paint works or how long it stays on.
Q: Which is the most damaging to a tire: underinflation or overinflation?
A: This is like asking me which tastes best, milk chocolate or dark chocolate? The answer for both the tire and the chocolate is BOTH. There are so many variables with tires, such as load, speed, road conditions, distance, and temperature that will have different effects on underinflated or overinflated tires, so it’s almost impossible to answer your question accurately. The best answer is to use the proper inflation.
Send your questions to:
Today’s Tire Industry
1532 Pointer Ridge Place, Suite G
Bowie, Maryland 20716-1883
or e-mail publication@tireindustry.org.
