Post by William McCormick on Jun 11, 2012 18:07:24 GMT -5
I am sure many people have heard a tire blow out, on the road. If you were watching it when it happens, you will often see a large white cloud of smoke as the tire bursts.
Most people do not think about it. However as a welder, you have to think about it. Good welders do not weld on rims, while tires are mounted on them.
I have to admit while in a hurry one day, I did weld on a tire rim, however I had wet rags around the weld, to absorb the heat before it made it to the tire. Not a good idea though at all.
The reason tires are so dangerous is because they contain petroleum products. When you heat a rather stable substance like diesel fuel. It can create many cubic feet of vapor, hundreds or thousands of times the volume of the liquid diesel fuel, used to create the vapor.
In a tire, there are also substances to turn the petroleum into rubber or plastic, depending on which school you belong to. They use catalysts to make the rubber solid. Most of the catalyst reacts out as the tire is manufactured. However if you heat the tire the reaction starts all over again. And can be lethal.
Here is an amazing video about Pyrolysis, made by Bridgestone tire and rubber company.
So next time you pull over to inspect a smoking tire, be very careful.
I once blew both left-side twins on my refrigerated truck. Luckily, I had brought a second spare tire that day, because another truck had gone to maintenance and didn't need it. Nobody had welded on my rims, though, but I became the victim of an unfortunate combination: Soft rubber, extreme heat and sharp asphalt edges.
Post by William McCormick on Oct 17, 2014 17:40:29 GMT -5
If your tire pressure is low enough the heat from the sidewalls can also do that. Or if dual rear tires are low enough in air pressure, they can rub against each other and that can also cause violent tire failure. Bad brakes or bearings can also do that. Glad you did not have to walk.