Tell us about yourself!
Okay, this will reveal my ignorance, but no time like the present to improve myself. I am assuming that these old coolers are constructed by sandwiching a layer of insulation between thin layers of metal. If that is true, how would one hammer out dents? How do you access the bulged side of the dent without completely destroying the cooler?
Nope. Ninja is correct. The authoritative Ashley Book of Knots, published well before we were born settles this issue. People often make the same mistake while tying a turn and two half hitches. Instead, they reverse the direction of rotation and end up with a Lark's Head on the standing line. Not coincidentally, this is called "reversed half hitches". However, in the case of the taut line hitch, I know of no name for the hitch where the direction of rotation is reversed. It may work well, but it's not a taut line hitch.