For engineering applications that require water resistance, I personally recommend PETG. I’ve used it to create enclosures for outdoor electronics that need to withstand rain and humidity. The material doesn’t absorb water and keeps its structural integrity in wet conditions.

Hello TechInvertorX, If you’re looking for material that doesn’t absorb water, I agree with Simon, you can consider using PETG. Polycarbonate, or certain types of Nylon could also be a good fit since they are specifically treated for low moisture absorption. I would say Polypropylene is one of the best options though – it is a popular material for food packaging bottles and containers. But it might be more expensive, especially for prototyping a single of a few parts.

Hello TechInventorX,

Adding to the excellent suggestions already made, PETG is indeed a robust choice for waterproof applications, as Simon mentioned, due to its low water absorption and good weather resistance. Manon’s mention of Polycarbonate and Nylon are also spot-on, especially if they are treated to be moisture-resistant.

Polypropylene, suggested by Manon, is also an exceptional material for waterproof applications because of its natural resistance to water absorption and chemical corrosion. It’s widely used in medical and laboratory equipment due to these properties. While it might come at a higher cost, its performance could justify the expense depending on the specifics of your waterproof design testing.

Another material to consider, especially if you need rigidity and high strength, is ASA (Acrylonitrile Styrene Acrylate). It’s known for its weather-resistant properties and is less likely to yellow over time compared to ABS.

When printing, remember that the waterproof quality will also heavily depend on the print’s layer adhesion and overall density. Ensuring a fully sealed layer structure with minimal gaps is crucial for a truly waterproof part. Post-processing methods like epoxy coating or even acetone smoothing (for ABS) can further seal a print, but these techniques would not be compatible with all materials.

Choosing the right material is a great first step, but for your waterproof design, you’ll want to pair it with a 3D printing process that ensures a tight seal to prevent water ingress.

Best of luck with your waterproof testing!

Warm regards, Attila

Absolutely. If ABS parts can be made more water-resistant with vapor smoothing, it’s not my first choice for outdoor use due to its UV sensitivity. My experience with PETG in outdoor settings has been very positive.

And if you want to read more on this topic, you can have a look at this article: https://xometry.pro/en-eu/articles/3d-printing-water-resistant/