Well, learn something new every day. Pyrolosis. Never heard of it until now...




Here is a workers comp document on an incident with a heavy equipment tire. Seamed so strange I had to google it to see if there were other instances.
http://www2.worksafebc.com/PDFs/inve...5108320019.pdf



Play safe out there...

 

Wow. I didn't know anything about this. He said they have been documented to blow up to 22 hours later! Sheesh.

That problem doesn't seem to happen when setting the bead with ether, fortunately, but I wonder why not? Not long enough to get the pyrolosis started?

 

Knew welding not good with inflated tire. Did not know even with valve stem out and other details would still happen. Thanks for that video. Life saver.

 

Ether is quickly ignited and dissipated. This is welding a metal to melting point and metal retains heat VERY well. So now you have 90psi and hot metal. The metal heats up the air, and you know what follows.

 

This is more than simple pressure rise from a hot wheel. It's decomosition of the rubber. Like burning. That seems to be the heat that causes the explosion. He said it has been documented to take up to 22 hours to explode. Wheel heat would be gone way before that. And when it goes it builds pressure so fast it will even re-seat the bead and explode. A serious chemical reaction!

 

We've actually been a witness from this. We were pulling a skytrack on a 32' elite trailer and we were slowing down to make a turn after going 55mph and when we turned our trailer brakes were smoking so bad I could of probly seen the fire if it wasn't so brite outside. Well about 15minutes later we had two tire blow out. We thought it was the weight of the skytrak because my brotheres 06 3500 couldn't get past the 55mph mark. The tires blew with such force that it blew off the boards from the attached angleiron broke the screws an all.

 

hmmm, we had a lightning strike at my job (car dealer) last summer, took out 3 cars parked next to each other. The one we thought that took the brunt of the hit, the radio antenna was melted, pretty much every computer/integrated circiut was fried and all 4 tires were blown out. The tires left tread imprints sorta like a tattoo in the pavement, I wonder if this is what happened to the tires. This was a brand new minivan which was repaired and now serves duty as our customer shuttle with no further problems. The other 2 veh`s were used and subsequently scrapped/totalled.

 

Guilty of using a torch to break lug nuts loose.

Last winter I had a little leak on a tractor rim. The factory weld was cracking. I just let all the air out of the tire and welded the entire bead all the way around the rim. Thought nothing of doing it. After watching that video I will never do that again!

 

Glad there wasn't any fix-a-flat...

 

Pyrolosis or something, a reaction in the rubber.

 

this type of situation is common with farming also.

My Fire Chief is a farmer, he was out working in his field one day, he went to pull out, and part of the implement he was pulling with the tractor came in contact with a power line.

Blew all 4 tires, and actually caused one to burst in to flames. It cost over $2000, for him to replace the tires.

 

There is something in that video that says 185 degs. F is the magic number to start the pyrolisis.

I would suspect the ether would not hit that number long enough for it to start,
but welding even for that short of a time could.

No heat for me from now on........

 

I have welded MANY a Bud nut or cap to a broken wheel stud to remove them. Never had a single problem. I never weld a rim on any of my equipment anyway, they crack, they are replaced with new ones.



Great info, thanks for sharing it.