First of all I'd like to say I'm grateful that Rip Trippers did the Nautilus head build to show me the basic steps to rebuilding the head. OK... so here are the problems I encountered with the Rip's Nautilus coil rebuild. It worked great for a while as long as I never exceeded the voltage the cotton wick could handle, and if I exceeded it one time it burned and had to be rebuilt. I also couldn't chain vape because it couldn't keep up with enough juice flow... once again burning the cotton. The head couldn't be dry burned to clean off the gunk from my favorite 40/60 PG/VG juice which is a popular juice from Epic Juices and an all day vape for me. Gunked up after a few tanks. The position of the coil in the head meant building a new coil to change the wick. There was just no way to remove the coil and reinsert it after re-wicking because the leads were too short after the initial build and clipping the excess off the wires. There was just no way to reinsert the same coil and get the 2 leads back in the original position before inserting the pin through the rubber grommet. At least for my skills.
So here are the results after 28 builds and learning a bit.
Coil Position:
This was the biggest problem with Rips build. He set the coil in the same place as the original upper coil. This didn't work for me. I have decided that the lower coil and wick MUST be in place to wick juice to the lower coil before the juice can be wicked to the upper coil location adequately. Think of it as a juice relay from the bottom coil to the top coil. The answer is surprisingly simple though. Put the new single micro coil in the same location as the original LOWER coil so it can wick the juice without going dry after chain vaping 4 or 5 hits (and of course burning the cotton). Huge difference, but just as easy to build. Even with cotton this is a dramatic improvement. Just make sure the coil goes to the bottom of the lower coil channel so that the wicks sit right at the bottom of the channel in the outer polyfil sleeve... just like the original lower coil did. The wicks need to touch the bottom edge of the channel to really wick well. Sounds finicky, but isn't at all. You can look through the bottom of the head since the pin isn't in yet and see exactly where it is and adjust it by pushing or pulling the wire leads coming out the bottom. Wicks juice great, even 100% VG like Boba's Bounty. Oh... and while you're here, once the coil is where you want it bend over one lead to the side of the head and that will hold the coil in place while you install the rubber grommet and the pin (this will be the ground/negative lead). This makes sure the coil won't move. Rip made it look like you have to be really careful here, but by bending the one wire the coil will not move and no extra caution is needed to insert the grommet and pin. Just slap it together.
Wick Material:
Cotton wicks well but is just too fragile if it can't be changed without pulling the coil... and I haven't figured out how to pull the coil and reinsert. This meant recoiling just to rewick. I tried 2mm and 3mm silica (3mm being best for me) and the wicking was fine although the flavor was a bit muted, but still couldn't sustain a good dry burn without getting damaged. It might work if you have the patience to dry burn very slowly, but patience is not one of my more prominent virtues. I have settled on 2mm Ekowool (which is really 3m OD since the measurement of this material reflects ID). This works really, really well. The flavor is on par with cotton IMO, and has the advantage of being able to dry burn like a ..... To test this I boiled the head for 20 minutes (after gunking with several tanks of 100% VG juice...Boba's) and dried for 5 minutes with a hobby heat gun, then dry burned until the coil glowed red over the entire surface 20 times in a row, starting from a completely non-glowing coil each time... not just pulsing. These were 5 to 10 second burns...each burn. I didn't need to dry burn this much, but wanted to see if I could destroy the Ekowool. Total overkill on dry burning. The Ekowool is fine and looks white as new. Then I took a small artists paint brush and brushed of the ash from the coil, blew it out, and it looked great and fired perfect. Understand I couldn't brush the bottom of the coil, but it is firing great so that is good for me. Juice wicking is really good. After 2 or so hits I can always see bubbles rising to the top of the tank... just as it should.
Coil Build:
Build whatever coil you like, just realize you are constrained by the width of the head you are putting it in. You do not want the coil touching the polyfil sleeve around the outside. I use 28ga kanthal around a 2mm bit and have built with 5/6 to 8/9 wraps (pinched micro coils) and all worked well. The 5/6 wrap ohmed out to 1.25ohms and the 8/9 wrap ohmed out to 1.68ohms. I am currently using the 8/9 wrap and vape my juice at 4.2v on my Provari, so naturally you are going to see much better vapor production with higher voltage. And the juice flows really well, so it's not a hot vape either. I could never vape above 3.6v with cotton without burning. I don't recommend higher than 2mm bit for wrapping the coil so you have adequate airflow around the coil. Going bigger seems to restrict airflow some. Might just be me, but that's what I noticed. You could go smaller if you prefer though. I build the coil like a regular micro and thread the Ekowool (or silica if you decide to use that) after the fact. Before inserting I torch the Ekowool for about 30 seconds which hardens it a bit and keeps it from fraying and cut a small angle on the tip. It also burns off any contaminants if there are any. Then I get it nice and wet on the end and shape it into a point and twist it counterclockwise through the coil. Goes in very easily. Clip each side just a tiny bit wider than the diameter of the head and with your finger nail fluff either side a bit so it expands and feels very soft to the touch. That's it for the coil build. Just insert in the head and reassemble.
Final Thoughts:
I'm sure people more experienced with builds could make some recommendations that would improve this more, but I feel this performs much better than the stock head. For me the vapor production is much better and the flavor is excellent. Not RDA excellent (got to stay realistic) but the same flavor as my KayFun, which is my benchmark right now for flavor in a tank. Plus, I can dry burn the coil... big plus for me.
I have run these builds on my Neme also. Since my target is voltage is 4.2v, the Neme runs this tank great. It doesn't really perform any different than it does on the Provari, but it looks great since the Neme is a 22mm mech and so is the Nautilus and tends to draw a bit of attention.
Added bonus. I have 3 Nautilus tanks now. I left one stock and drilled out the other tanks largest holes to 3/32 and 7/64. The stock is just under 1/16. The new build wicks juice great even with the 7/64 hole tank with no dry hits or flavor muting and the vapor production is improved quite a bit (vapor production with the stock head is still very good, but this is really a big improvement if you're looking for more vapor). This tank will handle more airflow quite nicely and if you're looking for more open lung hits, this will really surprise you. And the best thing is it leaves the other 3 settings exactly as they were with no changes. If you decide to do this use a new quality (titanium) drill bit and feed the drill press slowly so you don't wind up with a jagged edge at the top of the bore making it very difficult to turn the AFC ring. I did that on the first hole I drilled and spent the next 15 minutes with a small channel lock on the AFC ring working the ring back and forth to clear the sharp edge of shavings around the inside hole. It turned out fine and the ring moves perfectly now, but thought I would pass on my mistake. There is plenty of room on the base to drill even bigger, but I'm happy with it for now.
