1) Fire Hot
2) Things that touch fire are hot
An oxy-acetylene torch cuts metal at around 6,000 degrees Fahrenheit. Is it really necessary to do the "quick finger touch test" to see if something is hot after it has been cut? Shouldn't the answer be obvious?
Answers: No you shouldn't touch it and YES it's still hot. So why the heck do I keep doing it?
UPDATE: Things that burn skin instantly through thick leather, heavily insulated gloves are blankety, blank, holy mother blankety, blankety, blanking HOT! and yes that is a formal, technical welding term.
3) Metal Tough - Skin Soft
4) Keep both hands on the grinder
Things that slowly grind through metal quickly slice through "soft stuff". One afternoon I became complacent and ever so briefly touched my gloved hand with wheel of a grinder. It instantly sliced through the thick cow hide leather and pulled out the lining. Not smart!
5) Flame "Resistant" not Flame "Proof"
Here's why welding clothing is marketed as "flame resistant" and not "flame proof"...
6) Gloves Good
Closely relates to fire hot, metal tough - skin soft and keep both hands on the grinder
7) Clamp work to solid object before applying grinder
Grinders are powered by very strong electric motors that spin at thousands of rotations per minute. It shouldn't be surprising that objects touched by a spinning grinder wheel tend to move. You only have to shoot a piece of metal across the shop a couple of times before you grasp this concept. Unfortunately, I don't seem to have completely figured this one out just yet. Closely relates to face shield is your friend and Keep both hands on the grinder
8) Face shield is your friend
Only have to bounce sparks, debris and other junk off that clunky thing a couple times to appreciate it. Luckily for me I learned this early on and have since made it a mandatory piece of equipment for any grinding, cutting or impact kind of activities. The scratches, pit marks and scoffs in my shield prove this lesson.
9) Welding mask is required
Hate to even admit to this one, but early on I actually forgot to drop my welding mask before striking an arc. The first spark was bright enough to make me stop, but it took me a couple more seconds to consciously realize why.
10) Gloves shouldn't smoke
If you smell burning cow hide immediately move your hands. Closely relates to Fire Hot, Things that touch fire are hot, and Gloves Good.
11) Measure fifteen times and still cut it the wrong length
Laugh now, but you will eventually find that you ask yourself these questions... "Did I intend to cut this on the inside or outside of that chalk mark?", "How the heck do you divide fractions of inches?", "Why would anybody use inches and feet to measure building projects?", "Why/how did I cut the second piece the exact same length as the first incorrect piece?", "Why/how did I cut the third piece even further from the intended length than the first two incorrect pieces?".
12) Metal Heavy
The law of Gravity dictates that the unsupported piece of metal that you are cutting will fall to the floor once severed from the supported piece. Murphy's law dictates that it will hit your right foot on the way there.