Ultimaker Original clogged nozzle (removed from print head)

[LePaul 316]

I tried an atomic but the filament that is clogged inside is Colorfabb XT-CF20 (carbon fiber). I heated to 250 then cooled down to 100C....stuff wouldn't budge loose. Slowly brought the heat up a couple degrees and it finally popped out at 185C Problem is the stuff totally plugged up the nozzle.

I've removed the nozzle and wondering the best way to clean....dangle over a candle? Then some poke some regular filament inside (while hot) , then cool and pull? Rinse and repeat?

[neotko 1,417]

I usually first just purge the hotend with pla, then when the pla starts to exit almost clean, then I do atomics. Can you extrude anything or it's totally clogged?

[LePaul 316]

See pic

I have the nozzle out. And as I mentioned there, may be time to replace the brass pipe, teflon tube and peek.

[LePaul 316]

Well....to give some follow up...I used a candle to loosen and get some of the carbon fiber filament out. But...that also generated a fair amount of soot. (Regular, unscented candle)

I re-installed the nozzle into the print head (just a few turns, left in loose) and heated to 180C. I also tightened the brass tube into the heater block, it had become loose...once that was tight, I tightened the nozzle in. Then, at 220C i started doing atomic pulls with PLA filament(bowden tube removed). The first 4 or 5...heat to 220C, then set to 90C...then tug filament out....generated good "popping" sounds and soot. Finally, around the 8th time, I was able to press in the PLA and see filament squirt out the nozzle.

Phew, not a fun time but all back together again and printing