FilamentFacts
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Watertight

What filament is waterproof?

First in this ranking: Prusament PETG.

Ranked filaments

RankFilamentMaterialNozzleBedPrice / kgDatasheetRetailer
1Prusament PETGPETG with a listed nozzle of 240–260 °C and bed of 70–90 °C, plus a datasheet. The usual pick in this consensus.PETG
240–260
70–90
Not listedDatasheetNot configured
2Polymaker Polylite PETGPETG with a listed nozzle of 220–250 °C and bed of 70–90 °C, plus a datasheet.PETG
220–250
70–90
Not listedDatasheetNot configured
3Bambu Lab ASAASA, the other rigid option named. Listed nozzle 235–260 °C and bed 90–110 °C. Not a seal by itself.ASA
235–260
90–110
Not listedDatasheetNot configured

When to use which material

Start with PETG. Use ASA when the part is also outdoors and you can print ASA. Do not pick a fiber-filled grade to stop a leak. The leak path is between layers. PLA is not the consensus pick for a vessel.

Temperatures and settings

Print hot enough to fuse the walls, inside the nozzle range on the row. Prusament PETG lists 240–260 °C. PolyLite PETG lists 220–250 °C. Add walls and keep flow high enough that the seams close. Those two settings are not stored on the filament record. Dry PETG first. Wet PETG is a drying problem and it will not seal.

Failure modes

A leak at the seam is under-extrusion or too few walls, not a bad brand. A leak after a week outside may be the wrong polymer for sun, which is the outdoor question. A part that must not leak even if a layer is short is the epoxy case. The coat is not optional for critical use in this consensus.

Caveats

Nothing in the table is a waterproof certification. Epoxy is recommended for critical use and is absent from the filament catalog. Do not describe a PETG datasheet as a hydrostatic rating.

Where this sits in the catalog

Prusament PETG versus PolyLite PETG is the pair of usual picks. Bambu ASA versus Prusament ASA is the ASA pair if the part also lives outside. Printer fit for PolyLite PETG on a P1S is that settings page.

Pros and cons

Pros

  • The consensus puts the process ahead of the polymer, which matches how leaks actually happen.
  • PETG rows have listed temperatures, so the ‘print hot enough’ part of the advice can be checked.

Cons

  • Epoxy is the critical-use recommendation, and epoxy is not a filament in this database.
  • No row is certified watertight. A datasheet link is not a pressure test.

Printer considerations

Printer limits

What the community says

The consensus is that watertightness is mostly settings, meaning walls, flow, and temperature. PETG is the usual pick. ASA is also named. An epoxy coat is the recommendation for critical use.

Sources & notes

Accessed 14 October 2026.

Answer JSON · Markdown

Related questions

Questions

Will thicker walls make PLA waterproof?

Walls and flow are the consensus, and PETG is the usual polymer. PLA is not the material this question names. Outdoor sun is a separate reason to avoid PLA, covered on the outdoor page.

Is the epoxy a product you rank?

No. There is no epoxy filament record. The coat is a finishing step from the consensus, not a catalog row.