There are many different materials that can be used to create 3D prints. And depending on which material you use, you may or may not be able to achieve a waterproof 3D print.
To be able to produce a waterproof 3D print, you need to know which materials do and don’t react to water. If a material does react to water, then it will almost certainly deform or become unstable when exposed to water.
For your 3D print to be totally waterproof, you should look at using a print material which does not react to water.
Before I proceed to look at which print materials are best suited for producing watertight 3D prints, I’ll first quickly review the term waterproof. Many may mix waterproof and watertight, however for a 3D print to be waterproof, does not always mean it is watertight.
A waterproof material will maintain it’s form and consistency when exposed to water, and will not react or deform in any considerable way.
On the flip side, a print which is watertight requires a model which does not let water in or out. This requires the print material to be waterproof, and the model itself to be constructed in a way which does not allow water to pass through.
For example, a plastic cup will be constructed from a form of plastic which is waterproof, meaning it’s properties and structure do not change when we fill it with water. However, if you knock the plastic cup over, the liquid will escape, therefor it is not watertight.
In contrast, a plastic bottle with a sealed lid is watertight. Once the lid is sealed liquid cannot enter or escape. This bottle is both waterproof and watertight.
In this guide, we will be focusing on the former, and will bring you tips on how to make your 3D prints waterproof.
Which Materials Are Suitable
The first step of creating fully waterproof 3D prints is with your material choice. Generally, by using these materials alone will allow your prints to be able to withstand liquid. However, you may need to want to post process your prints afterwards to ensure they are as effective as possible.
Polypropylene or PP is a commonly used filament that is often used across the packaging industry. It is known to be hydrophobic which allows it to repel water. Due to this, many packaging items such as bottles are constructed using this type of filament.
It is a solid, strong and flexible choice for 3D printing with, especially if you’re looking for a water-repellent result.
When it comes to choosing a strong material to print with, ABS is always a good choice. It has great properties such as heat resistance and strength. However it can be slightly harder to produce a good print with than standard PLA.
It is however waterproof, meaning it is an excellent choice.
If you fancy a slightly easier print challenge than ABS, then PET-G is a great choice. Just like PP above, it is widely used in packaging, especially for liquid bottles. It is stronger than PLA, and easier to print with than ABS. Whilst producing a result which is both strong, flexible and liquid-repellent.
Tips For Printing
Below are a few tips to use when printing. These should help improve the waterproof ability of your final print.
1. Print Thick
Simply by thickening each wall of your model will help reduce the likelihood of any liquid being able to leak through. This technique will also increase the rigidity so bare that in mind if you need flexibility in your model.
2. Keep It Simple
The more complex your model, the more areas there are for your print to fail or leak. To really ensure your print has the highest chance of remaining waterproof, you shouldn’t introduce any extra details than required.
Increasing the flow rate of your 3D print will purposely allow you to over-extrude your print. This will essentially print slightly more material than normal, allowing each layer a better chance at merging together. This isn’t overly recommended if you are producing a model where precision is crucial.
4. Add More Shells
In a similar fashion to my first point, printing thicker walls… Adding extra shells to your print will also boost the barrier between one side of your print and the other. The more shells you print, the thicker the barrier, and more potential your model has to be waterproof.
How To Post Process To Ensure Your Prints Are Waterproof
The best way to ensure your finished 3D print is waterproof is to correctly post-process it. You should apply the tips which I detailed in our post-processing smooth 3D prints guide.
Essentially, by smoothing your final print, and reducing the layer steps, your model will have less potential weak points for liquid to erode or leak through.
Every physical step that is in your finished 3D print produces a place where a drop of liquid can hide. If those same steps were smooth, that drop of liquid would run straight off your print, rather than lingering.
It isn’t as hard as you may think to produce a completely waterproof 3D print. By understanding the materials you are using, and with a good knowledge of the print process and post-processing, you will be producing waterproof 3D prints in no time.
What are the best materials for waterproof 3D prints?
The best materials for waterproof 3D prints are ABS, PP and PET-G
How to make waterproof 3D prints stronger
You can apply a few techniques for increasing strength, including printing thicker walls, over-extruding and printing more shells.
How to post-process waterproof 3D prints?
Follow our guide for producing smooth 3D prints for the best tips on how to post-process your 3D prints to be waterproof.