Do not use a bench grinder without gloves!
I thought to myself, as I placed a small bit of metal up against a wheel, "what kind of gumbie does this?" and then I found out! The piece went flying and dragged my finger and thumb up against the wheel taking a good millimetre off each! Jeeeezus!
Blood everywhere....but quickly abated. Damn sore now though.
Lesson learnt. A colleague who teaches technology told me that a friend of his was doing a safety demo in front of a class of kids, showing how not to do it and in the process chopped the top of his thumb off! So, anyone can do it. Trouble is, you can get complacent.
But, as I say, lesson learnt.
(Annoyingly, that was my only usable welding tip that went flying. Took workshop apart looking for it, but no joy. Next time a tip gets blobbed up, I'll hand file it clean.)