In the earliest Darwins, the arm was not internally sealed. Evolv corrected that issue over a year ago. However, I still use sealed 510 to 510 adapters on all my Darwins as sort of a belt and suspenders approach. For my first year of vaping, I dripped pretty much exclusively (and used 801 style attys - most leak prone style). Dripping is sort of a learned over time thing but leakage from an atty is ALWAYS from over dripping.
Back in April of last year I posted a lengthy post in this thread about dripping. Drew referred to it as "DripUversity". Here is a link to that post and perhaps you, and/or others, may find it somehow helpful:
http://www.e-cigarette-forum.com/forum/nhaler/151096-darwin-evolv-290.html#post2964829 As that post is well over a year old, here are a couple of little updates: 1) disregard the dry-burn suggestion as it is not only not necessary but it also can risk damaging the nichrome and shortening the life of the atty - however, blowing out your attys a few times each day is still a good idea. 2) for 510 and 901 attys - I'd suggest using a drip shield (Drew carries some) - and they work fine on 510s if you add an adapter to extend the length allowing any juice coming out thru the atty airholes (in threads) to only come out into the dripshield (the adapter allows the threads of the atty to actually be inside/between the o-rings of the shield so any leaked juice stays in the shield). For 306 attys, the DCA is a no-brainer (they do not leak and hold a nice amount of juice). For 801 style attys - well, read the post.
Now I am using carto tanks pretty much exclusively so it is really no longer an issue as long as you are careful when refilling the tanks (spillage). I still use the sealed 510 to 510 adapters anyway and have developed the habit of looking at the device regularly as additional precaution. I am not sure if Drew has the sealed adapters in stock ATM but I'd imagine if you ask nicely...
I was an original tester of the final pre-production Darwin. Darwins are actually very well sealed now and the only way to get juice into them is if it gets in thru the button or the wheel. If it gets in thru the button, it can gunk up the button and cause the button to stick; if it gets in thru the wheel, it can gunk up the pot - neither is good and should be avoided. Just a little awareness and it becomes a non-issue. While I did, one time, get juice in thru the wheel - was carelessly filling a tank and was leaning over another Darwin sitting on its edge so the wheel was directly under where I was pouring - I have never had juice get into any of my Darwins from over-dripping leakage.
Hope this is somehow helpful.
