{
  "opening": "Smooth-On says its cured epoxy coatings are not UV resistant and should be primed and painted for use outside. That sentence does not make PLA heat-proof or UV-proof. Which filament to print for the sun is the outdoor page, not a coat of paint.",
  "question": "Should you paint a print that stays outdoors?",
  "slug": "weatherproof_paint",
  "useCase": "outdoor",
  "useCaseLabel": "Outdoor",
  "updated": "2026-10-28",
  "shortAnswer": "Smooth-On says its cured epoxy coatings are not UV resistant and should be primed and painted for use outside. That sentence does not make PLA heat-proof or UV-proof. Which filament to print for the sun is the outdoor page, not a coat of paint.",
  "recommendedMaterials": [
    "asa",
    "petg",
    "pla"
  ],
  "printerConsiderations": [
    "The filament for sun and weather is [outdoor filament](/answers/outdoor). PLA outside is [PLA outdoors](/answers/pla_outdoor). PETG outside is [PETG outdoors](/answers/petg_outdoor).",
    "Smooth-On's XTC-3D page says the coat works on PLA and ABS, sands, and takes primer and paint. The outdoor-epoxy FAQ says the cured epoxy is not UV resistant.",
    "A finish that is only about sanding, not weather, is [sanding](/answers/sanding)."
  ],
  "pros": [
    "The UV limit is Smooth-On's own FAQ, so a coating is not treated as a new heat rating.",
    "Heat-deflection numbers stay on the filament sheets that were already checked."
  ],
  "cons": [
    "Smooth-On does not publish a PLA or ASA heat-deflection number for a coated part. The uncoated sheet still applies.",
    "A comment that names a spray brand is that person's report. It is not the paint maker's data sheet."
  ],
  "community": "A comment says sunlight softens PLA from heat before UV damage shows. Another says paint helps UV exposure and that PLA still breaks down from heat and moisture. A third says an XTC-3D coat on a printed boat stayed watertight for about a year outdoors.",
  "related": [
    "outdoor",
    "pla_outdoor",
    "petg_outdoor",
    "sanding"
  ],
  "faq": [
    {
      "q": "Should you paint a print that stays outdoors?",
      "a": "Smooth-On says its cured epoxy coatings are not UV resistant and should be primed and painted for use outside. That sentence does not make PLA heat-proof or UV-proof. Which filament to print for the sun is the outdoor page, not a coat of paint."
    },
    {
      "q": "Does a clear coat make PLA safe in the sun?",
      "a": "Smooth-On's outdoor FAQ says cured epoxy is not UV resistant and should be primed and painted for exterior use. XTC-3D's page says it coats PLA and ABS and can be painted. It does not say the coat raises PLA's heat deflection. [Outdoor filament](/answers/outdoor) is the material choice. [PLA outdoors](/answers/pla_outdoor) is the PLA case."
    },
    {
      "q": "Can the curing heat soften the print?",
      "a": "XTC-3D's page lists mild heat as 60 °C / 150 °F for about a 15 minute cure, and says some print plastics melt above 200 °F. PolyLite PLA's sheet lists glass transition at 61 °C (142 °F) and heat deflection at 60 °C (140 °F) under 0.45 MPa. Those are the plastic's numbers, not a license to bake the part."
    }
  ],
  "sources": [
    {
      "title": "Smooth-On XTC-3D product page",
      "url": "https://www.smooth-on.com/products/xtc-3d/",
      "kind": "manufacturer"
    },
    {
      "title": "Smooth-On, epoxy outdoors FAQ",
      "url": "https://www.smooth-on.com/support/faq/208/",
      "kind": "manufacturer"
    },
    {
      "title": "PolyLite ASA technical data sheet V5.4",
      "url": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_ASA_TDS_EN_V5.4.pdf",
      "kind": "datasheet"
    },
    {
      "title": "PolyLite PETG technical data sheet V5.4",
      "url": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_PETG_TDS_EN_V5.4.pdf",
      "kind": "datasheet"
    },
    {
      "title": "PolyLite PLA technical data sheet V5.4",
      "url": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_PLA_TDS_EN_V5.4.pdf",
      "kind": "datasheet"
    },
    {
      "title": "Community source, r/3Dprinting 14fzv2c",
      "url": "https://www.reddit.com/r/3Dprinting/comments/14fzv2c/",
      "kind": "reddit"
    },
    {
      "title": "Community source, r/3Dprinting nfs7n9",
      "url": "https://www.reddit.com/r/3Dprinting/comments/nfs7n9/",
      "kind": "reddit"
    }
  ],
  "recommendations": [
    {
      "rank": 1,
      "note": "Catalog nozzle 230–260 °C (446–500 °F) and bed 75–95 °C (167–203 °F). Heat dataset checked 21 October 2026 lists heat deflection 103 °C (217 °F) at 0.45 MPa and 100 °C (212 °F) at 1.8 MPa, ISO 75, and glass transition 98 °C (208 °F). The sheet is the heat record. It is not a paint instruction.",
      "brand": "Polymaker",
      "product": "Polylite ASA",
      "material": "ASA",
      "url": "/brand/polymaker/polylite-asa",
      "nozzle": "230–260 °C (446–500 °F)",
      "bed": "75–95 °C (167–203 °F)",
      "pricePerKg": null,
      "datasheetUrl": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_ASA_TDS_EN_V5.4.pdf",
      "affiliateUrl": null
    },
    {
      "rank": 2,
      "note": "Catalog nozzle 220–250 °C (428–482 °F) and bed 70–90 °C (158–194 °F). Heat dataset checked 21 October 2026 lists heat deflection 78 °C (172 °F) at 0.45 MPa and 75 °C (167 °F) at 1.8 MPa, ISO 75, and glass transition 81 °C (178 °F). Drying on the sheet is 65 °C (149 °F) for 6 h, checked 18 October 2026.",
      "brand": "Polymaker",
      "product": "Polylite PETG",
      "material": "PETG",
      "url": "/brand/polymaker/polylite-petg",
      "nozzle": "220–250 °C (428–482 °F)",
      "bed": "70–90 °C (158–194 °F)",
      "pricePerKg": null,
      "datasheetUrl": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_PETG_TDS_EN_V5.4.pdf",
      "affiliateUrl": null
    },
    {
      "rank": 3,
      "note": "Catalog nozzle 190–230 °C (374–446 °F) and bed 25–60 °C (77–140 °F). Heat dataset checked 21 October 2026 lists heat deflection 60 °C (140 °F) at 0.45 MPa and 58 °C (136 °F) at 1.8 MPa, ISO 75, and glass transition 61 °C (142 °F). Smooth-On's cure note says some print plastics melt above 200 °F. This sheet does not say a coating changes those temperatures.",
      "brand": "Polymaker",
      "product": "Polylite PLA",
      "material": "PLA",
      "url": "/brand/polymaker/polylite-pla",
      "nozzle": "190–230 °C (374–446 °F)",
      "bed": "25–60 °C (77–140 °F)",
      "pricePerKg": null,
      "datasheetUrl": "https://cdn.shopify.com/s/files/1/0548/7299/7945/files/PolyLite_PLA_TDS_EN_V5.4.pdf",
      "affiliateUrl": null
    }
  ]
}