cleaning PLA off threads (v2 hotend)

[alaris2 1]

I saw someone having problems with re-using a heater block with the new hotend but there was PLA on the threads.

I also remembered reading an excellent article from Bertho about dissolving PLA with caustic soda.

I think I remember someone suggesting to use this method to clean the parts prior to assembly.

I just thought I should mention. don't try this. I forgot aluminum reacts big time with caustic soda and put the v2 hotend in the ultrasonic bath..

on the plus side, I have enough hydrogen now to power a fleet of fuel cell cars..

any safer ways to remove the PLA welcome (just heating it doesn't seem to work very well when it's stuck in nozzles and threads)

[joergen 1]

any safer ways to remove the PLA welcome (just heating it doesn't seem to work very well when it's stuck in nozzles and threads)

heating (to 220C) is perfectly adequate to remove the nozzle and the brass tube without much force. use 2 M6 nuts tightened against each other if the nozzle is stubborn. you can then remove any left over from the nozzle by heating it, and wiping the pla from the threads with a q-tip (works inside the tube as well (when hot), just remove some of the cotton if it doesn't fit, and for obvious reasons, use paper sticks, not plastic). heat gun is great, a gas stove will do as well. to clean off the remains of PLA from the brass tube threads, use a M6 die thread cutter, it works wonders rejuvenating the threads.

[alaris2 1]

Aha, thanks Joergen! taking it to pieces wasn't a problem but cleaning the PLA out from inside without scratching or damaging the internals was what was giving me trouble. I'll try some q-tips tonight!

[polymorph 1]

I have found that simply heating it up to 220 and leaving it there for a half hour or so, all the PLA runs out the end. Then it comes apart easily while hot, and PLA dissolves in Acetone, or as suggested wipes up with a Qtip while still hot.

[joergen 1]

PLA dissolves in Acetone, or as suggested wipes up with a Qtip while still hot.

just for clarification, ABS does dissolve in Acetone, PLA doesn't: http://www.vinland.com/blog/?p=68

[polymorph 1]

Hm... what the heck did I use, then? No sarcasm, I believe you. I don't recall what I used.

[alienrelics 0]

I think I did use acetone, and it broke down the PLA rather than dissolved it.