Weird Buildup Around Nozzle Threads

[thechewiestbacca]

Every time I finish a long or overnight print, when I check it out in the morning, or when it's done, there is a blackened and "gummy" buildup around the exposed threads of the nozzle of what I presume is filament. Also, when I heat the nozzle up to clean that buildup with a wire brush, the nozzle becomes loose and usually falls out. While this issue doesn't impair me from printing, it's kind of a pain in the butt to clean and reinstall the nozzle (then re-calibrate) before each print. What causes that buildup, and how do I avoid it?

Note: I have the HE280 with a .35 E3D nozzle installed on a Romax v2

[geneb]

You don't have the nozzle tightened properly.

g.

[thechewiestbacca]

Alright, thanks. Glad it was an easy fix

[nebbian]

Remember to tighten the nozzle fully when hot. Tightening when cold results in the behaviour you describe. Also PETG seems to find its way to the threads more easily than other filaments, I've found.