Just a few questions to satisfy my curiosity...
What brand and model of tank are you currently using?
How long is the coil lasting before you have to change it?
What is it doing for you to think it's defective?
What resistance is your coil?
What kind of juice are you using (PG/VG ratio and is it really dark and/or sweet)?
With the answers to the questions above we might be able to help you make a coil last longer. Dark, sweet juices will burn out a coil faster then light, not as sweet flavors.
Usually when using a rebuildable deck only the cotton needs to be replaced once a week or so. I can go longer, but I find after a week or so the flavor seems to be the issue, and replacing the wick after dry burning the coil makes it like a new coil.
KandyKlouds reacted to Tam in Rebuildable Coils and Coil Life Span?