how many wraps and what is the diameter of the coil
if you make the diameter too big, the wick can work fine at first, then after a while the cotton can sink down like a wet cloth leaving the top of the coil unwicked, and the top ends up getting too hot.
I use 30g kanthal, and with all the drill bits i had on hand, I couldn't make a build that was >2 ohms and also exceed 6 wraps (I figured, hey, surface area is important). I wanted to shoot for ~10 wraps, and the mini screwdriver that came with my rda happened to work out for me. I don't know the exact diameter, but I just went to a site and plugged in some numbers and I'm guessing about 1.4-1.6 mm diameter of the screwdriver based on calculated values from the website.