First, great instructional post! I started soldering in the mid 60's, scratch building slot car chassis. In the early 70's, I repaired pc boards as a communication tech in the Army, and I've built many a Heathkit. After a 15 year hiatus, my sons and I have returned to the hobby. I read your post because I think I've killed 3 Tekin RS esc's from too much heat. I am using a Hakko, and I was soldering at 750*-800*. I've since turned the iron down to 650*, and I might make a heat sink to clip onto the esc posts while soldering. I didn't know about using flux, and I will start in the future. While I agree heat is the number one killer of electronics, I don't know about the 6 second rule when soldering 12ga wire to esc posts... Anyway great post; a lot of useful and instructional info.