Abandoned printing a few years ago, getting back into it. I have several rolls of PLA and one ABS. The PLA rolls are brittle due to being stored in the open for years. I ran them through a dryer at 50c for 12 hours with no improvement. I’ve seen suggestions online for 55c so I’m trying that right now, but I imagine they’re fucked.
Will more heat help or am I wasting my time?
Edit: another 10 hours at 55 did nothing, I’m abandoning the spool and trying the ABS at 65 for a full day. It wasn’t brittle to start so I’ll have to test print to know if it worked, but I’ll post an update here for posterity.
Edit: ABS 65c for 24 hours. Clogged immediately. Didn’t have a needle handy, so I took a Sim card removal tool and a lighter, heated it up for about 30 seconds and stuck it in the top of the hot end and let it cool, then yanked it out. Weird thing was there was still some pla left in the hot end, so it clogged early and pushed out nothing.
The issue is not so much humidity as it’s micro cracks. You can try annealing the PLA in an oven. Try it repeatedly, increasing the temperature by 5°C each time. Should be fine at the latest at 70-75°C, but this might also change the dimensions of the filament, making it unusable.
But filament is so cheap that it’s likely not worth the time and the electricity to try to fix small left-overs.