RTA questions

Got a Cleito 120 tank which I'm more or less happy with. Only issue has been doing big hits has burned coils out very quickly. Rather than not hit it so hard I bit the bullet and ordered an RTA for it.
So I watched the video before but have a few questions more related to RTAs in general rather than the specific one I have.
Is the dry burn of a coil just to clean it? Does it damage the coil?
How long will/should a coil last? Maybe this can be answered in how many times changing the cotton? :P

So the outline I have is attach the coil(s) to the base, add cotton as shown, wick it to prime it then vape away?

Thanks.

Steve666

The dry burning of the coil is to make sure that current is going through each loop of the whole coil, rather than just jumping from loop to loop at one point.

In the image below, the coil on the bottom is fine, but the coil on top - you can see the current jump from one loop to the next at a single point, which will get very hot.

https://i.ytimg.com/vi/z8-S7w-BLF4/hqdefault.jpg (couldn't get that link to show...)

This only applies only to 'contact coils', where each loop is pressed tight against the next. If you space out each loop then current has no choice but to go through each loop fully, and you do not need to dry burn them, only to maybe check that they are installed correctly and heating up ok.

Whether or not this damages the coil...? Some say it does. It surely can't be good for it.

Some people will leave coils in for months, dry burning them to clean them each time they rewick them, but I find they get a bit manky after a couple of goes - the nice smooth shiny coils will start looking gray and rough. It's easy enough to install the coils anyway - to be honest, getting the wicking right is the problem!

5 goes and I'm done trying.
First time the cotton burned straight away.
Every time since the cotton comes out clean but trying to use it just stinks and the taste is stomach-churning.

Steve666

Hehe, it can be frustrating alright. When it burned the first time, did you clean out the whole RTA? Like, a decent hot water and Fairy scrub and rinse? And maybe the chimney too? Burned cotton is absolutely gross alright.

Dr Bill V1.5

Dry burning coils is necessary for a few reasons,it removes any hot spots on the wraps which can effect coil performance. It also cleans the gunk off the coil when you are re wicking. If you dry burn the coil at a temperature about 50% lower than you're going to vape at it will be fine,use a ceramic tweezers to strum the coil,this will help to give the coil an even glow and will also help to clean it.
A coil maintained in this way can last for months with regular re wicking. Re wicking will depend somewhat on the type of juice you use, juice that contains a high level of sweetner will gunk up a coil and wick very quickly.
When wicking use enough cotton to fit snugly in the coil, not too tight or loose. With the new rta's they really don't need much cotton going down into the juice channel's, just enough to cover the top of each channel is usually enough.