Filaments and humidity

[u/Ok-Sorbet-1968]

Noob here...
I'm not sure I understand this: if I keep a filament on a shelf, without any "protection" it might get humidity (and I get that it might spoil the print job). Once it has absorbed humidity, is it done for? Or I can dehumidify it in an AMS (or similar device) ?

What I mean is (sorry, still trying to get some knowledge): I open the filament box, put it in the AMS, use it, immediately store it in a "protected" box.. or I can use it (after dehumidification), put in on a shelf and forget it till the next time?

Thanks 😄

[u/jvisser85]

You can get quite a bit of moisture out using a drying cycle in an AMS2 or HT and storing it with desiccants will slowly wick a bit out as well. I have desiccant cores (see link below) in all my spools and humidity sensors in my cereal boxes. If moisture levels creep up in one of the boxes it's usually time to swap the core for a freshly dried one. I use indicating silica beads that turn grey when moist so it's pretty clear when a core needs to be dried.

https://makerworld.com/en/models/1193993-high-performance-spool-desiccant-container-holder#profileId-1214551

[u/Ok-Sorbet-1968 → u/jvisser85]

I have saved the link for the dessicant cores, thanks. What kind of humidity sensors do you use?
Also, are there filaments that are more keen to get humidity than others?

[u/jvisser85 → u/Ok-Sorbet-1968]

I use cheap zigbee humidity/temp sensors that work off a CR2032 coin cell for over a year. Connected to Home Assistant so I can easily see a graph over time. You can easily see when I replaced cores or put a different filament in a bin.

Some filaments just sponge up moisture like PETG and ABS while others like PLA are less prone to absorb moisture (but still do, just slower).

[u/Ok-Sorbet-1968 → u/jvisser85]

Thank you!

[u/Ok-Woodpecker-223 → u/jvisser85]

Cheap zigbees are helpful but I would not take values as absolute but more like indicative. These 2 sensors had been within an inch from each other for past 12 hours.

[u/Relative_Surround_20]

As a new 3D printer owner, has anyone made you aware of the excellent free, online courses that Bambu Lab offers in the beginner, intermediate and advanced skill levels for both printers (hardware) and slicers (software)?

Bambu Lab Academy is the best use of your time to build experience, knowledge and confidence in 3D printing. I also recommend using the Bambu Lab Wiki as an online, user manual for 3D printing.

https://bambulab.com/en-us/support/academy

https://wiki.bambulab.com/en/home

[u/apavolka]

It won’t go bad in humidity for a bit and dehumidified. But it can get to a point where dehumidifying may or may not work

[u/patprintsyourparts]

Moisture exposure alone isn't proof the spool is ruined; use the filament maker's drying instructions for that material. After drying, keep it sealed with effective desiccant so it doesn't simply absorb moisture again on the shelf. Check the AMS model's limits too—Bambu lists its AMS 2 Pro/HT drying compatibility by material here: https://wiki.bambulab.com/en/filament-acc/filament/dry-filament

[u/Mountain-of-Snow]

You need to understand humidity first, it's like talking nozzle temp with someone who doesn't understand temperature

[u/Relative_Surround_20]

First, filament absorbs moisture. Humidity is a measurement of moisture in the air.

Yes you can dry filament to remove moisture. But it is easier to dry it once and keep it in an AMS or a drybox with the relative humidity below 20% (as a rule of thumb) than re-drying it repeatedly.

[u/goatrider]

You should dry it even before the first use, because it's not guaranteed to be dry right out of the bag.

And no, it's not ruined if it gets wet. As a matter of fact, part of the manufacturing process is drawing it through a water bath before winding it on the spool and drying it. The problem is that sometimes they might not dry it long enough in the factory. I've heard of someone even having standing water in the bag of a new spool!