Also if I can add something. Trim the wick so it reaches the bottom of the juice channel and don't do the "v" cut on them either. 3mm ID coil is ideal for me because I feel that 3.5mm ID to be too much cotton for those channels. I don't chain vape or vape at high wattage. I have a 3mm ID dual 26 core with 36 wrap, ohms at 0.25ohms, 50-60 watts but temp controlled at 450F. Never had an issue with wicking as of yet. Also I leave the JFC wide open at night with 60vg juice and no signs of leaks in the morning.