Since writing this howto, I have been on another adventure. I have been playing with all sort of different ways of rebuilding and also have started to get a "funky" taste from some of my VN heads.
Just to put a few things in perspective, for all the above I am using Ego-T and Ego-C batteries only, no VV or high voltage devices. I am also using only my DIY juice, which is 65/30/5 PG/VG/Vodka (Flavour I am using is PG based and included in the PG part of the ratio. I don't want to discuss juices here, just giving my test base for those that care about test conditions
On newly rebuild heads I was getting a nice flavour and plenty of vapour at first, but after the flavour dropped off, I rebuilt them.
My favourite atty style is 6 wraps of 0.15mm nichrome wire from the c9v store (Counted from the top as number of times it crosses the wick). Legs are double twisted as above in the tutorial.
As I was getting a funky taste, I decided to build 2 atties of equal resistance (2.7ohm measured as in the tank ready to fit) I thought I would try removing the insulating caps, as I suspected they might be to blame (Some similiar material I tried as a replacement also gave off a similiar taste when heated).
I used 2 methods:
Method 1: Made the coil as normal, but tied some 1mm wick with a granny knot next to the coil, looped it under the coil and half hitched it to the other side. Then stuffed the lot (carefully) into a VN tank. Measured and tested 2.7ohm assembled.
Method 2: Made the coild as normal, left all insulation out and carefully inserted into a second VN tank. Measured and tested as 2.7ohms assembled.
Results (My wife kindly acted as an independent judge to verify my findings):
Method 1 - slightly more vapour from the extra wick around the coil - slightly tighter draw
Method 2 - better throat hit and better flavour, but slightly less vapour
Method 1 - slightly more robust and less prone to shorting as coil is insulated physically from the atty assembly, possibly better for out and about / tank cleaning and removal.
Method 2 - better vaping, but less robust with regards to knocks/shocks and tank removal, until further tests are carried out, I will be watching it carefully for any signs of shorting.
I use a VN as my only vape all day, and generally stick to just the one flavour all the time, so I have become used to it and its quite good for comparisons. I have only used one atty at a time, and never clean it - once the flavour is gone I rebuild. I tend to keep it as upright as I can, just cos Im not sure about leaking through the top, but have never had this happen unless I have over filled it. Generally I find that filling to just below the wick (for longer wicks) or keeping it below the atty line is good for preventing flooding and provides a nice consistant vape. Using a longer wick means more draws before wick wetting is needed, but means that you can't fill the tank quite as high. For reference, the bottom of my wicks generally tend to touch the sides just around the 2.10ml marking.
Hope this is of help/interest to some of you - sorry I can't be bothered to post pictures today, but if interest is there, I can do diagrams/pictures on request.
As always, please let me know any of your problems/experiences as I'm trying to learn all I can about this fab piece of kit (I now have 2 large VN tanks, and the missus has a large and a small - guess who does all the rebuilding
and the friend who converted me to vaping has also got me to order 2 for him - big thumbs up all around).