4 Ways to Dry PETG Filament (And Tips For Proper Storage)

Moisture is one of the primary factors that can easily ruin your filaments, causing issues such as your prints coming out suboptimal or the extruder of your 3D printer becoming clogged.

As moisture is quite common in most households, it’s typical for your filaments to absorb moisture at some point without you even noticing until after that something has gone wrong.

3D Print Beast - 5 Tips to Improve ... x
3D Print Beast - 5 Tips to Improve the Printing Process

Just like any other type of filament, PETG filaments can also suffer from moisture-related problems, meaning that you will have to ensure that your filament doesn’t have moisture before proceeding to print with it.

So, if you have been storing a spool of PETG filament for a while without usage, drying it before using it for printing is the best way to combat the moisture issue without having to deal with the problems it creates.

Fortunately, drying PETG filament is a straightforward process and can be done in a few different ways.

  • Filament Dryer Method – While the filament dryer method is the easiest one, it requires investing in a filament dryer, which may not be suitable for those on a budget.
  • Oven Method – The oven method is probably the most common method to dry PETG filament as you can use it with any oven, and ovens exist in almost every household.
  • Heat Bed Method – The heat bed method is one of the more creative methods, capable of drying your PETG filament without using anything other than your 3D printer.
  • Food Dehydrator Method – The food dehydrator method is another creative one, using a food dehydrator to dry the filament. While it’s not worth buying one just for drying filament, it’s a handy method if you already own one.

As all of these methods will allow you to dry your PETG filament without problems, feel free to pick the one that suits you best, depending on your budget and the accessories you already own.

Now, let’s get down to the details of each of these methods and how you can use them to dry your PETG filament.

4 Ways to Dry PETG Filament

Here are the four ways you can dry your PETG filament with ease.

Filament Dryer Method

If you store a lot of filament and use your 3D printer regularly, investing in a filament dryer is the best course of action due to how effectively this device dries filament with minimal effort.

A filament dryer operates quite similarly to a food dehydrator, heating the air in an enclosed space to remove the moisture. The device often comes with a heat setting, allowing you to set the recommended heat for your type of filament, meaning that you can use it with other filament types aside from PETG.

Here are the steps you can follow to dry your PETG filament with a filament dryer.

  1. Start by loading the filament into the filament dryer. Depending on the dryer you have, you may be able to load multiple spools if you wish to.
  2. Turn the filament dryer on, and set the temperature to 65 degrees Celsius (149 degrees Fahrenheit), which is the temperature that is recommended by most filament dryer manufacturers for drying PETG filament.
  3. Let the filament dry for at least 3 hours. That being said, the drying times may vary depending on the amount of moisture contained in the filament, ambient temperature, and humidity.
  4. If the filament hasn’t completely dried, let it dry for another 3 hours, and repeat until completely dry.

Some filament dryers also allow you to feed the filament to the 3D printer as it dries, which is a great way to ensure that there is absolutely no moisture remaining in the filament after pre-drying.

Oven Method

The oven method is undoubtedly one of the most commonly used techniques to dry a spool of filament without much effort, as it requires nothing other than a regular oven that you can find in most households.

As the electricity costs can quickly stack up if you regularly use your oven to dry filament (we recommend purchasing a filament dryer in this case), we recommend this method for those looking to dry a spool of filament that may have absorbed moisture as a one-off.

To dry your PETG filament with an oven, you can follow the steps below.

  1. Start by setting your oven to 65 degrees Celsius (149 degrees Fahrenheit) and let it pre-heat. As ovens can go above the desired temperature during pre-heating to accelerate the process, you should wait until the oven is ready to ensure the process goes smoothly.
  2. If you don’t trust your oven to hold the desired temperature, use an oven thermometer to double-check the temperature before placing the filament inside, as higher temperatures can melt your filament, rendering it unusable.
  3. Place the filament on top of one of the oven racks, and leave it there for at least three hours. As drying time can vary depending on factors such as how much moisture your filament has absorbed, repeat the drying process in cycles of three hours until the filament is completely dry.

Heat Bed Method

The heat bed method is surely the most creative one, utilizing the heating capabilities of your 3D printer to dry the filament. As it requires nothing other than a 3D printer, this method can be followed by anyone.

As the accuracy of temperature is vital for 3D printing, you can easily trust your 3D printer to dry the filament without melting it, making this a surprisingly good technique that is both easy and cost-effective.

That being said, you will need to somehow enclose the area around the filament, as simply leaving the spool on the heat bed will cause the ambient temperature to interfere with the drying process and cause it to fail.

To dry your PETG filament using the heat bed method, you can follow the steps below.

  1. Set the temperature of your heat bed to 65 degrees Celsius (149 degrees Fahrenheit) and wait until it reaches the desired temperature.
  2. Place your spool into an airtight container that can withstand the high temperature of the heat bed. While the best option is a heatproof airtight bag, wrapping your filament in aluminum foil should do the job if you don’t have access to anything better.
  3. Place your filament on top of the heat bed, and let it dry for 3 hours.
  4. After 3 hours, check the moisture level of the filament, and repeat the process in 3-hour cycles until all the moisture has dried.

Food Dehydrator Method

The food dehydrator method is the next best option after the filament dryer method in terms of effort, effectiveness, and cost (if you already own a food dehydrator).

As a food dehydrator operates quite similarly to a filament dryer, you can most likely skip having to purchase a filament dryer if you already have a food dehydrator that doesn’t get much use.

Here are the steps you should use to dry your PETG filament with a food dehydrator.

  1. Start by loading the filament into the food dehydrator. If your food dehydrator has extra space, you can dry multiple spools of filaments at once.
  2. Turn the food dehydrator on, and set the temperature to 65 degrees Celsius (149 degrees Fahrenheit).
  3. Allow the filament to dry for at least 3 hours in the food dehydrator.
  4. Inspect the filament after 3 hours have passed, and repeat 3-hour cycles until you are sure that the moisture is completely gone.

How to Identify Wet PETG Filament

Identifying wet PETG filament can be almost impossible as it’s very common for a spool of filament to look completely normal until the printing process starts and things start going wrong.

Here are the signs to look out for during the printing process to see if your filament has absorbed moisture, in which case you should stop the printing process as soon as possible.

  • Unusual sounds during print. Sounds such as cracking, hissing, and popping are usually a sign that your filament is wet.
  • Steam coming out of the extruder. If you see steam, it most likely means that the high temperature of your 3D printer is vaporizing the moisture that is contained within the filament.
  • Suboptimal print quality. If your model has issues such as stringing (hairy/fuzzy prints), this could be a sign that your filament has absorbed moisture.
  • Weak layers. If the layers of your model are not bonding as they should, a wet filament is a very common culprit for such a problem.
  • Inconsistent extrusion. If the extrusion varies in size across the parts of your model, even though they should all be equal, it could point to your filament being wet.119

If you don’t see any of these signs but still have doubts that your filament might have absorbed moisture, it’s best to dry it before using it to be on the safe side.

PETG Filament Storage Tips (To Keep It Dry)

Proper PETG filament storage is the best way to ensure that your filament stays dry and free of moisture.

After drying the moisture off your filament, storing it with these tips in mind will ensure that you won’t need to dry it over and over.

  • Keep your filaments in low-moisture areas. Storing your filament in a low-moisture room that is well-ventilated reduces the risk that your filament absorbs moisture. As a rule of thumb, the areas around the bathroom and the kitchen have higher humidity, which is why you will ideally want to keep your filament away from these areas.
  • Use dry boxes and dry cabinets. Dry boxes and cabinets are the best way to store your filaments in a completely moisture-free environment. These devices provide you information such as the temperature and the humidity inside, allowing you to monitor the status of your filaments. That being said, these devices are fairly expensive, which may be a dealbreaker for most 3D printing enthusiasts.
  • Use airtight plastic bags. Airtight plastic bags are the next best thing after dry boxes, and they are quite cheap in comparison. By simply throwing a desiccant pouch (such as silica gel) and a humidity indicator alongside the filament in the bag, you can create a budget version of a dry box where you will be able to track the humidity status of your filament while keeping it dry.
  • Use vacuum bags. You can use vacuum bags as an alternative to airtight plastic bags if you don’t have access to them. Just like in the case of airtight plastic bags, add a desiccant pouch and a humidity indicator for maximum efficiency.
  • Use airtight containers. Airtight containers are also a great way to keep your filaments dry on a budget. By simply combining airtight plastic bags (or vacuum bags) and airtight containers, you can most likely eliminate the possibility that your filaments ever get wet unless something disastrous happens.

What Temperature Should You Dry PETG?

We recommend drying your PETG filament at 65 degrees Celsius (149 degrees Fahrenheit) as this is the temperature that most filament dryer manufacturers suggest.

While you can most likely use slightly higher temperatures, you would be risking the deformation of your filament for no reason, as this temperature is perfectly sufficient to remove all signs of moisture.

How Long Does PETG Take to Dry?

While the drying time is affected by factors such as the method you use, humidity level, ambient temperature, and the amount of moisture your filament has absorbed, we recommend drying your PETG filament for at least 3 hours.

Please note that this figure is by no means conclusive, and the best way to ensure that your filament has completely dried is to inspect it and keep drying if there are signs of moisture.

Wrapping Up

Ensuring that your PETG filament is dry before printing is essential for a smooth printing process as moisture can easily ruin a print and cause trouble for the extruder of your 3D printer.

Fortunately, drying PETG filament is mostly a hands-off process where the only thing you need to be careful about is the temperature you set, regardless of the method you choose.

Considering that there is at least one suitable method for everyone as one of the methods we have outlined only requires a 3D printer, we highly recommend drying your PETG filament before printing if you are unsure about the moisture situation.