I'm still using my second built microcoil for however long it's been (me and time measurements don't mix well). Decided to pull out the head and replace the wick so I snapped pictures along the way to show
how I've been having the best results. It's not 100% perfect, there may be an occasional period where you start hearing the gurgles, in which case I immediately unscrew the tank off the battery and, with my finger over the mouth tip w/ a piece of tissue, flick it several times very hard to get everything forced towards the tip end. Take a few air drags with my finger over the battery connector end of the tank to confirm there's no gurgling, reconnect and go.
=== Mkay, lets start with the high-res pictures shall we? ===
This is what my head looks like when I removed it, this wick has gone through multiple tankful's worth of juices.
Popped the hood, you can see the coil is nicely gunked up from use (mostly 50/50 juices, also turned out that left side was getting hotter than the right)
Ran it under warm water to make it easier to see, normally I skip this step and go straight to removing the wick & dry burning.
Removed the wick (clipped one side and slide out the other. You can see my coil is... not straight anymore. It's gone through significant abuse as I forced different sized cotton during experiments in there distorting it over time. As long as it dry burns like a microcoil, aka red starts in the middle and moves out, seems to be fine.
Dry burned it by pulsing it for a few seconds on & off until I was satisfied, my eVic was set to 8w at the time.
After dry burning, a very good rinse is in order, and even a light toothbrushing if you want. This coil is probably nearing the end of it's life since it's not looking quite as new after this process.
Ripped some cotton off a ball, this part is an art and you have to acquire a sense for how thin you need the cotton to be.
Rolling it up, tight is good here or threading it becomes less possible. Again, this part is an art.
You want it to be somewhat loose inside the coil, if you grab one end and push in and out, it should be able to without the cotton just buncing up between your finger and the coil. What I do, once it's in like this, is slide it back and forth about half a cm which causes the coil to strip the cotton in the center making it a nice looose fit. This might require a microcoil that can handle the abuse, a normal pre-rolled coil may not maintain it's spacing, but I don't know for sure.
Now the fun step, I dont trim the wicks short, I tuck them in along that outer well until they meet opposite ends.
I think this is one of the critical steps, I snip the tips at a point so that tucking the remainder will fill every little gap, so it looks like one continuous wick. My reasoning is, you have to have the wick very consistent at the point outside where it enters the well, any gaps may make it more vulnerable to letting juice seep in.
Pop the chimney back on, and I think this part is also critical, I slide the grommet down all the way it goes, and make sure it snapps into the bottom ridge of the chimney. My reasoning, like the previous step, this grommet is there to cover the extra gap above the wick where it enters the well. With everything nice and dry, the wick should swell and form a good seal around everything ensuring no gaps (at least, thats my theory). Optionally, after the grommet is in place you can add some juice to the outer wick circle, but this doesn't seem needed. Just screw it into the tank, flip upright, give it a minute or two and it'll be saturated.
Wanted to show my tank right after, I only bothered to fill it halfway. I rarely do more than half a tank just because my vapors tongue is still in effect and I can barely taste a damn thing, and I like to switch flavors around anyways. It really doesn't seem to matter how full or empty the tank is, it works for me to the last drop with the rare gurgle that is fixed via flicking.
Final thoughts ===============================================
A fresh wick on a cleaned coil will produce amazing vapor and flavor with a creamy-like texture. It works better without an air-flow restriction, at least I find, I guess more air = better.
Performance, flavor, and vapor is at peak performance for the first tank's worth on a fresh wick. To maximize everything, it would be ideal to thread in a new wick, which is pretty darn fast and easy after acquiring a nack for it as shown above.
If switching flavors but the wick is still plenty fresh, I either just fill the tank w/ the new juice and go, OR, I rinse the head (without removing the chimney) under warm water. If you do this, you can screw it back in, but you will need to do short pulsing & puffing (dont bother inhaling, just trying towork the water out). I give a few good seconds between pulsing just to be careful, if that wick should dry burn, you'll taste it and it doesnt go away without replacing the wick. Once the water is out and it's saturated itself with juice, you'll know. Vapor production may not be quite the same as a fresh wick.
If I have juice in a tank not in use, I take off the drip tip and store it upside down. Theory is 1) the wick does not have a chance to over-saturate and 2) any excess juice in the well will have a chance to either rewick, or at least drip out the chimney via gravity.
I've only tried 50/50 DIY juices and 80/20 pre-mixed assrapepriced juices. High VG should work, just draw carefully until you know. I did have one dry hit with this setup on a 50/50 juice and holy hell was that the worst thing I've experienced short of receiving my aga-t2 cracked.
If you think you're getting a burnt taste, it's possible a previous hit didn't wick itself perfectly. It tends not to go away so just put in a new wick and resume. Right now my lost taste only allows me to detect burnt by french inhaling, so I don't know too much on this.
30g 12/11 wraps around a 16g needle is what I think I was using here, 30g 10/9 seemed to work fine as well, I dont know what the optimal microcoil setup is in wire thickness, number of wraps, or the circumference. I'm at a point, over 30ft of kanthal later, where I've experimented enough and just want to kick back (and get my sense of taste back .......mit) and enjoy.
Not sure how long a coil will last, but seems they can take a good beating. I thought when I built this coil (my memory is weak) it was measuring at around the 2.4ohms range, right now it's 3.0ohms. It gradually built up resistance, so I assume that just that alone may be an easy indicator when it's time to rebuild.
Stay hydrated! I dont know if drinking water is enough, my mouth isn't dry but feels like the inside of my mouth has developed wrinkles. They say moderation is key, but I say, if it's worth doing it's worth overdoing.