grruss....
I didn't have an insulator on my aluminum when I got it.
Two things, and I'm no expert:
I, and others, have other genny type
devices that don't use insulators. Others have used their Zens without an insulator.
It is said that with a well oxidized wick, an insulator is not necessary.
Now, I know Zen put one there for a reason, and I won't advise you to use an item that isn't "stock", but just to try to solve your problem, have you tried yours without the insulator, just to see if your coil is too close and burning the the PTFE and/or if there is a problem with the new ones you put in?
Second,
I don't know what it's called, but Katz had posted that she is using a piece out of an old carto.
Since my aluminum was sans insulator, I didn't have one handy and didn't want to wait for an order.... LOL
I used this piece as well.
I was going to just skip it, but all my pre-made wicks were to thin to use without something there, and I was too excited to try it out to take the time to roll a different one.
If you have a carto, dual coil is best because the piece is longer.
It looks almost like material to me.
And it works, and works well.
I didn't have anything to actually take the carto apart, so I just carefully pulled the innards out
through the top.
It's inside the batting, whitish/yellowish in color, 1 to 2cm long and almost looks like canvas.
I can try to get some pictures if you want......