Which Filament Is Suitable for Outdoor Use?
For permanent outdoor applications, ASA is often one of the most sensible default choices, because it resists UV light and higher temperatures well. PETG can also work for many less extreme outdoor applications and is easier to print. PLA is usually not the best default choice for parts under long-term sun and heat exposure.
Several stresses act outdoors at once
Rain isn't the only factor. An outdoor part can be exposed to:
- UV radiation
- high surface temperatures in the sun
- frost
- fluctuating humidity
- mechanical load
- wind
- fastening and sustained load
ASA
ASA is especially interesting for permanent outdoor mounting, holders, hooks, covers, end caps and technical enclosures. Downside: more demanding print, warping, an enclosed build chamber is often worthwhile.
PETG
PETG works well when outdoor exposure is moderate, easy printability matters, and moisture is a factor.
PLA
PLA can work for short-term or protected applications. For a part that stays mounted unprotected in sun and heat for years, a more suitable material should be considered.
Design matters too
The best filament won't help much if the hook tears along the layer direction, the wall is too thin, water pools in a pocket, or screw holes sit right at the edge.