I wrapped my first coil Friday & it worked unbelieveably well right off the bat. Then I bumped it w/the top after refilling the tank & it never worked the same after that. I didn't empty the tank & wrapped a second one. It started out fine, but developed a hotspot I couldn't pinpoint. I figured I could use some more practice & I had messed w/it long enough that I think the bad coil had sorta tainted my juice, so this evening I pulled everything apart & cleaned it up good. Wrapped a new coil around the same wick & it's back vaping like a champ. I wish I knew where that hotspot came from tho...still a LOT to learn here. BTW, I noticed that the center tube is different on each end, & I guessed when I reassembled. It's not leaking, but which end goes where?