Filament Storage

I set up the school with the 5 gal plastic bucket with screw on lid and home-made desiccant packs as described by Wolfie in the “A Strategy for Obtaining Great Prints” thread. It’s a great set up: convenient, compact, and effective atmosphere control. The classroom now has two 3D printers (the Mini I gave them, and a Polar 3D) unfortunately, they don’t use the same diameter filament, so they are going to end up with a stock of both 3mm and 1.75mm

My question is, which types of filament are the most sensitive to moisture in the atmosphere? If controlled atmosphere storage space becomes scarce, are there some types that must be kept in a dry atmosphere, and some for which it doesn’t matter much? They’ll likely be printing with PLA, HIPS, and ABS for now, but may branch out into other types in the future.

Pla and hips both seem to react worse to water. Abs absorbs more, but the higher print temperatures seem to make it less noticeable. Smaller diameter filliament is more prone to showing moisture effect.

It might be worth converting one of the hotends to match the other filliament size. You can take a hexagon to 1.75 if nothing else.

Thanks. I’m guessing we may eventually convert both to the same size. We may live with the different sizes for now, until the the warranty period and leaning/troubleshooting/dialing in are done.

It seems to depend on your room climate. I have a quite warm and dry home (always about 23°C and <40% humidity) and I have no problems with storing my PLA “open air”. The oldest rols are now about 5 month old and there is abolsutely no sign of degradation.

Thanks, Sebastian. We’re fairly dry now, in the winter months, but it won’t stay that way as we get into spring - especially in a room full of 20+ 5th & 6th graders. There is no AC in the school, and things can get a bit rank as the seasons warm up.

It’s a tough call, but if you HAVE to leave something exposed I’d probably choose the HIPS. I’ve had less trouble with it than others when it comes to moisture. But I really recommend keeping it ALL in sealed containers with desiccant if at all possible. Moisture just causes too many problems with print quality.

I started with 5gal buckets and the screw-on Gamma lids, adding (2) of these desiccant packs in each bucket:

I didn’t like that solution for a couple reasons:
(1) Each bucket and lid combo was about $12, and two desiccant packs were $7.50. That’s $19.50 per bucket, and each bucket generally held only 4 spools, so that was $4.88 per spool for storage.
(2) I couldn’t see the filament spools through the buckets.

I later switched to the “Ziploc 44qt Weathershield Box” (upc 762016448824):
(1) Cost is about $16 each. Add two desiccant packs ($7.50) and you have $23.50 total for each box. But each box can hold (10) standard spools, so that’s $2.30 per spool for storage.
(2) You can see through them!

There is also a 60qt version of the Ziploc Weathershield Box that brings the cost-per-spool down a bit more, but I found them to be a little too big to handle and stuck with the 44qt model. YMMV.

Some photos are attached. I added some elastic cord at the top to hold the desiccant packs, but you can just throw them in the bottom (they fit between the spools).