I thought I was getting fantastic wick-life with rayon. I was re-wicking my derringer last week, it has a pair of 2mm inner diameter 26/32 kanthal 4/5 wrap 'clapton' coils, compression wound. Comes out to a quarter ohm. Anyhow, the wick tails were still white, with a very slight caramelization right next to the coil. I grabbed the tail with my tweezers to cut it next to the coil so I could pull the other tail easily, but the wick had already burnt through at the center, leaving a little singed, tan cone.
I had ran around 200 ml through the wicks, I think the rayon burn-off/degradation must have had happened over time, because I never tested burnt rayon (though the atomizer performance difference was immediately noticeable with new wick).
I've only had this problem once, though all my atties are wicked with rayon, though most have naked SS coils in them, so I'm going to attribute this burn-out to the extra mass of the complex coil, and me being lazy and not performing a complete trailing draw.
Could be the wick was still caught on the Clapton and pulled apart even though you cut one side. There has been only like 2 reports from people saying this type of thing and kinda, since it's not common, we didn't determine what happened.
Did you maybe burn it by accident then decide to Rewick.
I burned one purposely and it was still in one piece. So when you pulled one side out you had an end, the other side was still in the coil then. Was the Rayon black on the end or just brown? Burned will have a carbon tale on the end.
I mean think about it.. How is it possible to vape away with no wick in the center. You would get horrible dry hits. I think it just pulled apart on you. The reason is because each fiber is a fixed length like 1-1 ½ inches, and all stacked overlaying each other. it will pull apart if you have a bunch of ends left that are 1/8" long fibers and then a bunch of 1" fibers and you pull on the 1" it will seperate or pull from the 1/8" fibers leaving them on the other side.
If you play with a piece of rayon if you grab it at the fiber length say 1" apart, you can not break it it's strong as a rope. If you grab it 2" apart you can easily pull it apart
I think the above is what happened. The following is ideas on how I think you could damage the Rayon. Even though I have never been able to reproduce it in regular use.
You do create a hot spot in the center with a contact coil. Extended overheating there for 200ml I suppose could cause a burn of the Rayon. But many have done contacts past 200ml with the Rayon still fine through the coil. You would see black burnt ends if it burned though. Literally there have only been 2 or 3 that's burned the wick just by user error.
imo, the most common is the wick being loose in the center causing the excess heat to be exasperated in the center of the coil, due to poor wick contact overheating the coil. Most wicks I've seen that burned through were because they were loose not tight and low on available juice to draw into the coil.
When the coil glows the wick can not keep up with that kind of temperature and could spot dry possibly causing the burn under those coils that don't have good contact, if there's not enough juice on the wick.
One other problem with contact coils is you can't see if you have good contact in the middle. Try leaving at least a small space so you can see the wick.
Look at my last posts I'm talking about a similar issue. Being able to see the wick in the coil you can spot when the coils are not making solid contact to the wick. Looking straight across the top of the coil from the side you can see if the wick is looser in the middle.
Tighter is better! But even contact is just as important.
Moral of long winded jumping story... It pulled apart is all.
still turned out pretty decent.
