welding a tyre rim is just dangerous business. ni kama kufungua ile coiled sheet metal inabebwa na trailer kutoka Mombasa na pliers. Or trying to uncoil those wires that hold up a bridge. Tyre rim imeundwa istahimili extreme stress round that near perfectly round spherical shape, so when you weld the rim you are weakening the stress holding ability and unleashing that force on your face. It can be done with small alluminium tyre rims but at a personal risk.
Deorro ndio huyo mzungu akuambie kama huniamini juu sikusoma:
http://m.worktruckonline.com/article/1966/caution-welding-wheels-is-dangerous
The scenario the video demonstrates involves a fired-up welding torch rigged to point at a wheel rim mounted with a tire. A digital thermometer indicates the air temperature inside the tire rocketing higher and higher. The tire then blows, and the wheel rim and the dummy are blasted through the air. The sequence is part of a wheel-end safety video, produced by the Tire Industry Association and funded by Michelin North America (see sidebar).
Welding Can Cause Invisible Wheel Damage
Welding weakens a wheel, said Marvin Bozarth, a technical consultant to the Tire Industry Association. “The wheel is designed to operate at certain temperatures, and sometimes when you weld on it, the metal hardens and causes fractures that may not be visible,” Bozarth said. Such damage can lead to the wheel failing.
“Don’t weld them; don’t hit them with a steel hammer,” Bozarth said. “You’ve got to treat them nice and make sure they’re in good condition.”
Yet despite such warnings, some wheel welding does go on, Bozarth said. “I see it on some wheels,” he said, surmising the practice continues to be performed by “people who are just not informed, don’t listen, or they think they know better.”
He added, “That’s what gets people killed.”
Other Sources Pose Potential Dangers
Heat from sources other than welding, such as tire fires, also can damage rims, Bozarth said. An aluminum wheel, for example, should be inspected after a tire fire. An overheated aluminum wheel might have a damaged flange. A new tire mounted on such a damaged rim can come off, he said.
Use of ether, hairspray, or other flammable substance to seal beads on a wheel is an extremely dangerous practice, both during the procedure and potentially later if someone attempts to weld the wheel, Bozarth continued.
“Sometimes residue of that material remains in the tire,” he explained, “and when you weld on the wheel, it can re-ignite the residue and cause an instantaneous fire inside the tire.”
Likewise, welding a painted wheel can result in a fire. As the paint heats up, combustible fumes are emitted, Bozarth said. Also, welding near the bead can heat the tire’s rubber material enough to emit a gas that could ignite, causing a fire and possibly an explosion, Bozarth said.