Grinders and magic smoke.
When I was a kid, I was introduced to the concept of magic smoke. Ever heard the joke? The way it goes that electric components of all sorts work because of the magic smoke they contain; if you do something to let the smoke out then it stops working. I’m reminded of it because I let the smoke out of an old grinder just the other day.
…and speaking of grinders, isn’t if funny how guys always seem to send a five inch grinder to do a seven inch grinder’s job? When I was an apprentice, the only 5″ grinder that the company owned was issued to the senior journeyman and I think he only had it because he threatened to quit if he didn’t get it; the rest of us were issued 7″ grinders.
The bigger grinder sure removes metal in a hurry compared to the smaller ones, but you sure start feeling the weight pretty fast. A couple of us actually brought in 5″ grinders of our own for doing smaller grinding jobs. It was always amusing to watch the boss tap some fellow on the shoulder and tell(yell at) him that if he was going to be paid by the hour then he needed to use a bigger grinder. The fellow would pull out the 7″ and get back to work…until the boss went back to the office; then out came the 5″ grinder again. It would happen a couple times each week.
The boss had a point to make and I agreed with him but it was irrelevant because he was the boss. Those 5″ grinders are easier on the arms but don’t cut like the 7″ models and just don’t last as long as the larger ones when used continuously.
If a lot of grinding work comes my way then the compromise for my helper(because it sure as Hell won’t be me doing it) will be the use of pneumatic grinders. The electrical bill for compressing the air to run a pneumatic grinder will be higher than with an electric grinder(by a factor of about 5 in my experience) but the grinders themselves will last longer, run cooler (downright cold, actually), and weigh much less. I’m sure the comparison between electric and pneumatic angle grinders has been analysed to death elsewhere but unless a large grinding job falls in my lap I’m not going to do the reckoning and research any time soon.
I’ll bet that if all a fellow does is grind all day then his increased comfort, productivity, and tool life will likely offset the cost of producing compressed air.