Artículo: Best Materials for 3D Printing Boat Parts: PETG vs ASA vs Nylon
Best Materials for 3D Printing Boat Parts: PETG vs ASA vs Nylon
One of the best things about 3D printing your own boat parts is that you can make almost anything — a replacement fitting, a custom bracket, a lost cap. But a part is only as good as the plastic it's printed in. On a boat, that plastic has to survive UV, saltwater, heat, vibration and the occasional knock. Choose the wrong material and a perfect print can go brittle, warp or fade in a single season.
This guide walks through the materials that actually make sense for marine parts, when to use each, and the print settings that matter most.
Quick answer
| Material | Best for | Watch out for |
|---|---|---|
| PETG | General marine use, water fittings, cockpit & interior parts | Softens above ~80 °C; moderate UV life |
| ASA | Anything in the sun — deck, mast, exterior parts | Needs an enclosure; prints hotter |
| Nylon / CF-Nylon | High-load, high-wear parts (blocks, brackets, bushings) | Absorbs moisture; keep it dry before printing |
| TPU | Gaskets, bumpers, seals, anti-vibration mounts | Flexible only — not for structural parts |
| PLA | Prototypes and test fits only | Fails outdoors — heat and UV kill it fast |
PETG — the marine all-rounder
If you print one material for your boat, make it PETG. It resists water and most chemicals, holds up well to humidity, and is far tougher than PLA. It's easy to print on almost any machine and doesn't need an enclosure. That makes it the default choice for water and waste fittings, hose barbs, clips, holders and most cockpit or cabin parts.
Its main limits: it softens above roughly 80 °C (keep it away from engine heat and dark surfaces baking in the sun), and its UV resistance is decent but not the best. For a part that lives permanently in direct sunlight, ASA is the better pick.
ASA — for anything in the sun
ASA is the outdoor specialist. It has excellent UV and weather stability, so it won't yellow or go chalky the way many plastics do after months in the sun. Think deck hardware, mast and rail fittings, and any exterior part that never sees shade. The trade-off is that ASA prints hotter and really wants an enclosed printer to avoid warping and layer splitting — so it's a step up in difficulty from PETG.
Nylon and CF-Nylon — maximum strength
When a part has to take real load or wear — a rope block, a bushing, a bracket that carries weight — nylon is the strongest and most abrasion-resistant of the common filaments. Carbon-fibre nylon (CF-Nylon) adds stiffness for parts that must not flex. The catch: nylon soaks up moisture from the air, which ruins print quality, so it must be dried before printing and ideally printed from a dry box. It also needs a hotter, often enclosed, setup.
TPU — gaskets, bumpers and seals
TPU is a flexible, rubber-like filament. It's the go-to for anything that needs to squish or absorb shock: custom gaskets and O-rings, protective bumpers, grommets and anti-vibration mounts. It's not structural, but for seals and soft parts nothing else comes close.
PLA — why to avoid it on a boat
PLA is cheap and prints beautifully, which makes it perfect for a test fit before you commit to the real material. But it has no place as a finished marine part: it goes soft in a warm car — let alone a sun-baked deck — and it degrades quickly under UV. Print your prototype in PLA if you like, then print the keeper in PETG or ASA.
What about watertight, pressurised parts?
For fittings that hold water or low pressure — hose barbs, through-hulls, manifolds — the material matters less than how you print. Leaks almost always come from weak layer bonding and the seam, not from thin walls. PETG generally seals better than ASA. Print the thread axis vertical, slow the outer wall, add a little flow, and use a "scarf" seam. We cover this in detail in our guide to printing watertight fittings that hold pressure. Every pressure-rated design in our Plumbing & Pumps collection includes recommended settings.
Print settings that matter for marine parts
- Walls over infill: 4–5 perimeters do more for strength and sealing than high infill.
- Layer adhesion: print a touch hotter and slow the outer wall — this is what keeps water out.
- Orientation: put loads and pressure across layers, not along the seam.
- Dry filament: essential for nylon, helpful for everything.
- Finish: a wipe of marine sealant or a PTFE-taped thread turns a good part into a reliable one.
The MarineLab3D shortcut
Every design on MarineLab3D is parametric and print-ready, and each product page lists the materials it's tested in plus recommended print settings — so you don't have to guess. Want to try before you buy? Start with our free files and print one in PETG this weekend.