Introduction: Keep Filament Dry

About: Making and sharing are my two biggest passions! In total I've published hundreds of tutorials about everything from microcontrollers to knitting. I'm a New York City motorcyclist and unrepentant dog mom. My wo…

Storing filament properly is important for the quality of your prints. It will absorb moisture from the air, which will sizzle and pop as it passes through your printer’s hot end, causing blobs, under extrusion, and other defects.

Back in 2017, I showed you how to make a filament dry box, and while that’s a great project, a lot has changed since then and I want to update you on my current filament storage methods, and share some of my favorite things to print.

Supplies

Step 1:

The simplest and cheapest way to store filament spools is in plastic bags with a packet of silica gel. New spools come this way, but only some manufacturers use ziptop bags that you can reuse. Gallon freezer bags will do the trick, but the chonkier spools will be a tight fit, so to make them keep their seal for as long as possible, tape up the edges of the zipper.

Step 2:

But there’s still plenty of air in the bag, so if you want to level up this method, you’ve got to vacuum it out. A straw works moderately well, but lucky me I’ve also got a vacuum sealer. Sometimes the factory bags are big enough to reseal once or twice, but the most sustainable version of this method uses these special zip bags with a vacuum valve on them. I wouldn’t say you should go out and get a vacuum sealer just for your 3D printer filament, but if you want to use it in the kitchen too, maybe this tip is a good excuse for you to take the plunge.

Vacuum sealing will extend the life of your silica gel, but eventually, it will become fully saturated with moisture from the air. But you can recharge it by drying it back out. You can do this in the oven at its lowest setting for several hours, or depending on where you live, you may just be able to leave it out in the hot dry sun for a day. They even make silica gel that turns color depending on its hydration, so you can visibly tell if it’s ready to use. I also had luck putting my silica gel packets in the bottom of my 3D printer enclosure with a humidity sensor.

Step 3:

This one’s not a tip, but more of a “what’s new.” The Bambu Automatic Material System, or AMS, is a dry box and material switcher in one. It has compartments for silica gel in the back and a moisture sensor that’ll tell you when it needs changing. I love this thing.

While we’re in the world of new-fangled tools, I want to recommend picking up a heated filament dryer box like this one gifted to me by GratKit. It holds one spool at a time and heats it to the right drying temp depending on what type of filament it is. This is a great alternative to running your oven on low all day to dry out your wet filament, and it’s also a dispenser so you can keep your spool dry during extra-long prints, which is particularly important for some materials like nylon.

This thing is great but it can be noisy, so I customized it a little. The dispenser hole is perpendicular to the plastic lid, but the filament wants to come out at an angle. So I drilled a more vertical hole which stops the filament from catching on it and making a noise. I also added a bit of Teflon tube to help aid the filament’s transition into the printer, and now it doesn’t make any more noise. Except for the piercingly loud piezo buzzer inside, which I tried dampening with a little bit of nail polish. It’s still pretty loud but it’s also a safety feature that alerts you if it tips over, so I don’t want to remove it completely.

Step 4: Favorite Things to Print

My first favorite thing to print is planters. I’ve had some plants that have been happy in PLA planters for years, and they make great personalized gifts. They even make UV-sensitive filament, which turns a bright purple when exposed to sunlight. My favorite way to make geometric planters is with Codeblocks in Tinkercad, which makes it easy to create repeating shapes around a center point and run highly iterative experiments quickly. I’ve posted links to my source models and planter STLs at the link in the description and on Printables.com.

Another thing I like to 3D print is knitting stitch markers. These little plastic loops are critical for keeping track of your rows when knitting in the round as well as decreases and other multi-row patterns. But they’re easy to lose and also easy to print. So they’re a great gift for the knitter in your life. I recommend printing these in the highest resolution possible on your printer because they are super small and you want them to be smooth.

Naturally, the next thing I like printing is accessories for my printers, like a bucket for collecting the Bambu printer purge poops, and a little scraper for helping release thin layer prints from the print bed, both of which I found on Printables.com. And I modeled a basket for silica gel packets that goes inside my filament dryer, which is again much more efficient than using my oven with the door propped open.

My last favorite thing to recommend printing is a foldable crate design on Printables. I printed out a bunch in the original size and a scaled-up, and they are so useful for organizing my current projects and other things around the workshop.