Without strict adherence to safety rules, it is too easy to get hurt in school shop classes that involve welders and torches operating at every workstation.
In one incident, a student was at work under a Jeep chassis. His safety glasses had a slight tint and were making it hard to see in the dim light, so he took them off to get a better look. A few seconds later a bolt that was lying on the frame fell and hit him in the eye — fortunately, it didn’t cause anything more than a temporary ache.
Tinted safety glasses are useful when working outside or to help minimize the effects of arc flash if you accidentally touch a torch to a work piece without your helmet down when welding. For mechanical work inside the shop, clear lenses are the best.
Keeping disposable lens cleaning patches on hand inside the shop for safety glasses is a good idea.
A second shop incident did not involve an arc flash could have been much more serious. While using a wire brush attachment on an angle grinder to strip some paint and rust a student wearing safety glasses avoided possibly being blinded. Several wire bristles stripped off at the grinder’s rated speed of 12,000 r.p.m. and were flung back at the student. He was also wearing an additional full-face safety shield, which deflected the flying debris heading toward his face. When using tools like a grinder that send off fragments at high speed, ordinary safety glasses alone aren’t adequate. Always wear a full-face shield.
The student also wore heavy coveralls, which protected the rest of his body. Several of the flying bristles embedded themselves in the thick denim fabric. The metal fragments probably would have only caused minor scrapes if not for the thick clothing.