ABS can absorb moisture

I have been printing with ABS for about 3 years now and I have never worried about moisture and never had a moisture problem. However the last 2 weeks it has been very hot and very humid (humidity in the 70% range and heat into the high 90's F). I needed to print some parts (very important parts) and put on my trusty roll of black filament only to have troubles, it would clog often, surface looked messy and extruding in air (to fix a clog) showed the problem, under magnification I could see the extrusion was pockmarked with lots of little craters (from steam escaping).

I put the roll into my trusty franken oven (an old convection toaster oven I hacked with a learning PID controller years ago for a different purpose) and left it at around 89c for 2 hours. Removed it and started printing with it and it printed perfect.

So it just goes to show that new problems can pop up even when you think you have everything down pat.

Both ABS and PLA absorb moisture. That's why a spool of filament should always be supplied to you in a vacuum-sealed bag with a sachet of silica gel inside. Some filament suppliers include a spare ziplock bag and sachet of silica gel as well, for you to store the filament in after you have started the reel.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I live in California where it's fairly dry & my ABS absorbs moisture. It's not the most hydrophilic material out there though so once I dry it out & store it, it's good to go for a bit.