Should of used a silicone sock…
LOL and I thought mine was skanky 
Before I got the sock I cleaned mine with a brass brush after every print.
sweet baby jeebus that’s a massive layer of char!!
i don’t have socks on my hotends and they don’t look anything like this… clearly i’m not printing enough!
have a go in making one…
https://plus.google.com/112050613337136711262/posts/3EeK2pKXDs3
i purposely left the nozzle, so i could swap them…
but in later rebuild, instead of this i just wrapped heating block with PTFE tape. works even better, far less fiddling…
@Marko_Novak bought a pack of e3d ones to put on the hotend I got with the multi material upgrade
@Carter_Schunk
just as suggestion, if you don’t have one at hand, but have something else… silicone and ptfe are common in household, less so in apartments…
i had good results with my direction;)
There’s many legit ways to make or buy the boots. The new version of the E3D boots do allow for nozzle swaps now.
I don’t think a sock would help here. I looks to me like a leaky throat.
@Dan_Collins I agree – all that material got there somehow – that’s not just the usual carbon buildup. Something’s not quite tight enough?
@Mark_Wheadon it all came from a failed print that stuck to the hotend
@Carter_Schunk I stand corrected then, yeah a sock would of made things less charred. Although I’ve destroyed socks by dragging them through failed prints.
@Carter_Schunk Ah, right you are. Although in my experience that kind of frag fest pulls the sock off.
mine just after print 
gone true ~5kg of filament after last cleaning.
i just wipe it with paper towel before print.
https://profiles.google.com/photos/112050613337136711262/albums/6473893729787231441/6473893730039123250
@Marko_Novak So what is that wrapped with?
@Mark_Wheadon PTFE tape, thinner version, available in any local HW store.
typical household use… radiator plumbing.
@Marko_Novak That is a great idea! Do you use a special way to wrap it, so that is fixed? I remember that you need a little bit tension. Did you remove the nozzle before?
@Gerald_Dachs no, just wrap tightly.
so tight it almost breaks while wrapping… and with oil free hands, end sticks to itself.
whole hotend was assembled prior to wrapping, that makes it so easy… i intentionally left nozzle, since i knew i will be switching PLA/ABS/PLA, so potential clog… but it held, even petg after all that and tpu as first filament that went true since last cleaning (torch+compressed air)
next time i will try to also wrap nut portion of the nozzle.
for everyone who is interested…
after ~1kg of filament (since last nozzle cleaning/hotend assembly) on 0.35 nozzle… i got clog and hit reset. nozzle dropped from ~1cm…
ptfe tape held and separated from PLA cleanly, cleaning bit off from previous roll (black petg).
https://profiles.google.com/photos/112050613337136711262/albums/6486499058890994865/6486499063517506946
and bad picture of nozzle imprint on the failed part
https://profiles.google.com/photos/112050613337136711262/albums/6486499778577082273/6486499778523431506