{"id":30577,"date":"2025-07-18T15:09:44","date_gmt":"2025-07-18T15:09:44","guid":{"rendered":"https:\/\/letsprototype.com\/?p=30577"},"modified":"2025-07-18T15:35:31","modified_gmt":"2025-07-18T15:35:31","slug":"design-of-watertight-parts","status":"publish","type":"post","link":"https:\/\/letsprototype.com\/en\/blog\/2025\/07\/18\/design-of-watertight-parts\/","title":{"rendered":"Design of watertight 3D parts. Waterproof components."},"content":{"rendered":"
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Design and Manufacturing of Watertight 3D Parts: Instruction Guide<\/h1>\t\t\t\t<\/div>\n\t\t\t\t
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The <\/span>design of watertight parts<\/b> and their manufacturing through 3D printing represents a non-trivial technical challenge in the <\/span>prototyping industry<\/b>. Unlike traditional industrial manufacturing techniques, 3D printing is a layer-by-layer shaping process carried out in a much cooler environment and less conducive to material fusion.<\/span><\/p>

By <\/span>watertight part definition<\/b>, we refer to the <\/span>design of parts<\/strong> <\/strong>that, once manufactured, prevent the passage of liquids or gases through their surface. The challenge of <\/span>designing watertight parts<\/b> for 3D manufacturing lies precisely in the natural inconsistency (due to the fabrication method) of the resulting parts, depending on the chosen <\/span>3D manufacturing method<\/b><\/a>.<\/span><\/p>

Below, we list some of the measures we take at <\/span>Let\u2019s Prototype<\/b><\/a> to <\/span>achieve watertight parts<\/b> for <\/span>prototype assembly<\/b>. Some of these measures will affect the <\/span>part design process<\/b>, while others will specifically refer to the <\/span>watertight part manufacturing cycle<\/b>.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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Useful tips for designing watertight parts for subsequent manufacturing.<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Below, we share some <\/span>tips for designing watertight parts<\/b>, always with a view to their subsequent production using <\/span>3D manufacturing methods<\/b><\/a>. This specification is important because, in the future, when the <\/span>industrial manufacturing of the product<\/b><\/a> is required, a slight <\/span>redesign of the part<\/b> will also be necessary to adapt it to new production methods, which are generally more suitable for <\/span>manufacturing watertight parts<\/b>.<\/span><\/p>

Wall thickness:<\/b> To achieve <\/span>watertight 3D parts<\/b>, it is important to ensure the walls have a <\/span>thickness greater than 2 mm<\/b>. In some parts, depending on their use, this design may seem slightly oversized; however, based on our experience in <\/span>prototype manufacturing<\/b> with these characteristics, walls below this thickness often pose a risk of liquid leakage after the initial <\/span>watertightness tests on the prototype<\/b>.<\/span><\/p>

Surface regularity:<\/b> To <\/span>design watertight parts<\/b> that prevent fluid leakage, it is essential to maintain stable geometries\u2014meaning avoiding sharp edges or substantial changes in section across the <\/span>surface of the part design<\/b>. These <\/span>shape variations in the design<\/b>, although fully feasible for 3D printing, can weaken the <\/span>waterproofness of the parts<\/b>.<\/span><\/p>

Joints in the design:<\/b> The <\/span>design of parts<\/b> often requires joints or seams, which are <\/span>critical elements for watertight design<\/b>. The inherent tolerances of prototyping methods pose a risk to the <\/span>watertightness of the parts<\/b>. For this reason, when such joints are unavoidable, the design should incorporate <\/span>O-ring channel features<\/b> or utilize <\/span>raised profile design techniques<\/b> to ensure a <\/span>watertight connection between parts<\/b>.<\/span><\/p>

Avoid unsupported bridges:<\/b> The <\/span>use of supports in the design<\/b>, essential for the <\/span>shaping of the designed parts<\/b>, is critical to <\/span>achieving watertight 3D-printed parts<\/b>. Our <\/span>industrial design team<\/b> strongly recommends minimizing and avoiding, whenever possible, the use of bridge-like or overhanging surfaces without <\/span>robust support within the part<\/b>. Excessive use of support structures enables a more compact and sealed result during the <\/span>fabrication of watertight parts using 3D printing<\/b>.<\/span><\/p>

Gentle slope design:<\/b> If the <\/span>part requires slopes<\/b> or curves in its geometry, to ensure a <\/span>watertight part design<\/b>, it is essential to minimize the use of <\/span>sharp angles in the design<\/b>. These <\/span>angles in the design of watertight parts<\/b> can lead to porosity.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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3D Printer Settings for Manufacturing Waterproof Part Designs\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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To <\/span>materialize waterproof part designs in 3D<\/b>, proper calibration and <\/span>configuration of 3D printer settings<\/b> is essential. Below, we provide useful information to establish printing parameters for <\/span>watertight parts using FDM<\/b> and SLA technologies, which are the <\/span>most commonly used methods in prototyping labs<\/b>.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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FDM Printing Parameters for Manufacturing Waterproof Parts\n\n<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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Layer height:<\/b> Layer height refers to the thickness of each individual layer added during the <\/span>shaping process of the watertight part<\/b>. In these cases, a layer height of 0.1 mm is highly recommended to <\/span>achieve more compact parts<\/b>.<\/span><\/p>

Infill:<\/b> The <\/span>infill setting for manufacturing part designs<\/b> refers to the amount of internal material fill within the part. Considering the nature of 3D printing, to <\/span>achieve watertight designs<\/b>, it is essential to configure a 100% infill.<\/span><\/p>

Extrusion temperature:<\/b> The <\/span>material extrusion temperature<\/b> during the <\/span>shaping process of a watertight part<\/b> should be set high. This allows for better fusion between layers and helps prevent pores that could compromise the <\/span>watertightness of the part<\/b>.<\/span><\/p>

Line width:<\/b> The line width should be slightly larger than the <\/span>3D printer nozzle<\/b>. Specifically, at <\/span>Let\u2019s Prototype<\/b>, we set the printer's line width to 0.45 mm.<\/span><\/p>

Number of perimeters:<\/b> The perimeter setting for <\/span>manufacturing waterproof parts<\/b> should always be greater than 3 perimeters on the outer wall.<\/span><\/p>

Material flow:<\/b> The material flow setting for <\/span>watertight parts<\/b> should be adjusted between 105% and 110% in case of <\/span>under-extrusion<\/b>.<\/span><\/p>

Post-processing:<\/b> The <\/span>post-processing of 3D-printed parts<\/b> is critical for achieving a <\/span>functional prototype aesthetic<\/b> that closely resembles the appearance of final products. However, when it comes to creating watertight parts, <\/span>post-processing<\/b> is not only for aesthetic purposes\u2014it is also the key step for sealing any potential pores that could compromise the <\/span>waterproofness of the parts<\/b>.<\/span><\/p>

In <\/span>watertight part designs<\/b> manufactured with 3D printing, the post-processing stage often involves <\/span>manual techniques<\/b> such as the <\/span>application of epoxy resins<\/b> or other sealant coatings. We even apply photosensitive resins for subsequent curing of the part.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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SLA Printing Parameters for Manufacturing Watertight Parts\n<\/h3>\t\t\t\t<\/div>\n\t\t\t\t
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If the <\/span>watertight part design<\/b> is materialized using SLA printing techniques, it is essential to choose Tough-type materials. This family of resins is compatible with the properties of industrial-grade materials.<\/span><\/p>

Another useful tip for <\/span>manufacturing watertight parts with resins<\/b> using SLA is to ensure the longest possible curing time. This process guarantees maximum <\/span>part strength<\/b>.<\/span><\/p>

The <\/span>curing process of watertight parts<\/b> is so crucial to avoid pores that may compromise seal integrity, that at Let\u2019s Prototype we subject each <\/span>watertight part<\/b> to a post-curing process involving UV exposure in cycles exceeding 30 minutes.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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Recommended Materials for Manufacturing Watertight 3D Parts<\/h4>\t\t\t\t<\/div>\n\t\t\t\t
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Whether using FDM or SLA manufacturing methods, selecting materials that ensure optimal interlayer adhesion is essential. In the production of <\/span>watertight prototypes<\/b>, we commonly use the following:<\/span><\/p>

FDM: TPU, PETG, ABS + Acetone, Nylon.\u00a0<\/span><\/p>

SLA: Tough resin family, flexible resins, and TPU.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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How to Test the Watertightness of 3D-Printed Parts? <\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Before assembling the <\/span>prototype that requires watertight components<\/b>, the most critical parts must undergo standard <\/span>watertightness tests for prototyping<\/b>. Specifically, in our lab, we perform the following:<\/span><\/p>