I was teaching my son some shop practices today (can you see it coming?) and we had this old shop vac from the 70's that we were trying to rig up to use as a blower.
I was holding it up and running it when my son (13) told me he saw sparks from the motor. I looked and sure enough it was sparking somewhat. I mentioned to him that this blower was not safe in and explosive enviroment because it could cause an explosion. (still coming)
I was done with the "lecture" when I started running it again and heard a bearing running a little rough so I figured I could fix it. I turned it off and (here it is) sprayed some lithium grease from an arosol can into the works.
I turned it on and luckliy my son was behind me and the opening was down toward my arms and hands.
That thing went off like a freaking bomb as I was holding it in my arms. My son jumped like a bomb went off and I threw the motor across the room and when it hit the end of my overhead electrical cord it came swinging back at me and almost knocked me down with it's pendulum effect.
After recovering from the BOOM I looked down and saw all the hair on my arms was curled and black. I wound up with only a small flash burn on one wrist but my wife was not to pleased with my teaching method.
My son laughed so hard when I was showing and telling my wife about it because I had just done what I had warned him not to do and taught myself a real lesson.
Just had to share.
My arms still stink like burnt hair.