leaked almost 2ml's the first time I filled it. rebuilt it and filled it to just where the chimney pieces come together, no leak. Not sure if that make's all the difference or not but it hasn't leaked a drop yet this time. I don't want to tip it over to where the draw hole gets drowned out. lol, maybe I didn't put enough cotton on the wick to get it to catch the reservoir. Any tips? (no pun intended.) lol