Are 3D Printed Parts Waterproof?

May 1, 2024
White 3D Printed parts being tipped on their side to drain resin

Are 3D Printed Parts Waterproof? This question often arises in the world of additive manufacturing. This blog post discusses the intricacies of achieving watertightness in 3D printed parts, exploring various techniques and considerations.

Waterproof vs Watertight: Clarifying the Terms

White 3D Printed parts being lifted out of bed of resin after printing

Before delving into the specifics of 3D printing, let’s differentiate between waterproofness and watertightness. While waterproofness refers to a material’s inherent ability to resist water permeation, watertightness pertains to the object’s construction and its ability to hold water without leakage. With this distinction in mind, the quest for watertight 3D Printed parts becomes clearer.

Can 3D Printing Yield Watertight Parts?

Indeed, 3D printing offers the potential to create watertight components. Various technologies exhibit differing degrees of inherent water resistance. For instance, stereolithography (SLA) stands out for its capacity to produce watertight parts directly from the printer. However, technologies like Fused Deposition Modelling (FDM), Selective Laser Sintering (SLA) and Multi Jet Fusion (MJF) necessitate careful design considerations and possibly post-processing steps to achieve full watertightness.

Crafting Watertight Parts: Strategies and Solutions

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Enhancing the watertightness of 3D Printed parts involves strategic design choices and, at times, post-processing interventions. Reinforcing physical barriers through increased wall thickness and optimised infill density stands as an initial step towards achieving watertightness. Additionally, optimising design features to promote even pressure distribution can mitigate potential leakage points.

Formero’s industrial FDM printer provides customisable configurations aimed at enhancing watertightness. Choices like increased infill density, thicker layer extrusion, and printing within a controlled heated environment improve layer adhesion and reduce interlayer gaps, thereby advancing the printer’s ability to produce watertight parts.

Post-Processing for Watertight Integrity

Formero’s SLS and MJF printed components can have their watertight properties further improved through post-processing methods. This includes applying additional sealants such as Cyanoacrylate or Polyurethane coatings to the part surface, or utilising solvent smoothing techniques like Vapour Polishing. Notably, solvent smoothing is particularly effective on FDM, SLS and MJF parts, yielding not only watertightness but also a refined smooth surface finish and increased part strength.

Material Matters: Selecting the Right Composition

Person looking at 3D drawing on computer screen

While design and printing techniques significantly influence watertightness, material selection plays a pivotal role. Opting for materials inherently resistant to water, such as ABS or ASA for FDM applications, contributes to the pursuit of watertightness. For specialised needs, considering chemical resistance becomes imperative, ensuring compatibility with the intended application environment.


In the world of 3D Printing, achieving watertightness entails a multi-faceted approach encompassing thoughtful design, appropriate technology selection, and strategic post-processing. With Formero’s expertise and versatile solutions, the journey towards crafting watertight 3D printed parts becomes not just conceivable but achievable. Contact us today to discuss how our printing technology and post-processing services can help your next project.


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