Most filament advice is written for a mild northern-hemisphere climate. Perth is not that. We get 40°C summers, some of the highest UV in the world, and a lot of people printing in uninsulated sheds and garages.
Those three things break printed parts in specific, predictable ways. Here's what to use, and why.
The problem with a car in February
A closed car in a Perth summer regularly goes past 70°C inside, and dashboards well above that. PLA softens at 53°C.
This is the single most common thing we hear about — a phone mount or a dash clip that worked perfectly for months, then quietly drooped out of shape over one afternoon at the shops. It isn't a print quality problem and no amount of infill fixes it. It's the wrong material.
For anything living in a vehicle: PETG at 68°C is the minimum, ASA at 96°C is the sensible answer, and PC-CF at 117°C if it's near an engine bay.
UV is the slow one
Heat is obvious — the part sags and you know why. UV is slower and catches people out.
Perth sits under some of the strongest UV in the world, and ultraviolet steadily breaks polymer chains apart. The part fades, the surface goes chalky, and it turns brittle enough to snap from a knock it would have survived when new. Six months on a north-facing fence will do it.
PLA and PETG both degrade this way. ASA doesn't — UV stability is the entire reason the material exists, which is why it gets used for automotive trim and outdoor signage.
Printing in a Perth shed
Two seasons, two different problems.
Summer: an uninsulated garage can sit above 35°C ambient. PLA gets soft enough near the extruder to cause heat creep and jamming, and cooling fans have nothing cool to work with, so overhangs suffer. Print early morning if you can, and keep spools out of direct sun — filament sitting in a hot car boot or a sunlit shelf degrades before you've even loaded it.
Winter: a cold garage in July is the other extreme. Big ABS or ASA prints will warp and split from draughts alone. An enclosure isn't optional for those materials here.
Coastal humidity matters too if you're near the water. Filament absorbs moisture from the air, and wet filament gives you stringing, popping and weak layer bonds. The PLAs and PETG dry at 50°C for 2–4 hours; ASA and PC-CF want 80°C. A spool that's been open on the bench for a month is wet, whatever it looks like.
Quick answers for WA
| Where the part lives | Use | Why |
|---|---|---|
| Inside the house | PLA+ or Matte PLA | Cheapest, easiest, best finish. Nothing here will hurt it. |
| Workshop or shed | PETG | 17 kJ/m² impact and 68°C — survives being dropped and survives summer. |
| In a car | ASA | 96°C. PLA will not make it through February. |
| Full sun outdoors | ASA | The only one here that holds up to WA UV. |
| Near an engine | PC-CF | 117°C and the strongest thing we stock. |
| Garden or irrigation | ASA | UV plus moisture. PLA is industrially biodegradable — a liability in soil. |
Common questions
Can I use PLA outdoors in Perth if I paint it?
Paint slows the UV damage a little but does nothing about heat. A painted PLA part on a fence still softens on a 40°C day and still goes brittle eventually. Use ASA.
Why did my print work in winter and fail in summer?
Almost always ambient temperature. Higher garage temperatures cause heat creep in the hotend and rob your part cooling of any effect. Same file, same settings, different room.
Do I need a filament dryer in Perth?
If you print PETG, ASA or anything carbon-filled regularly, yes — particularly near the coast. For PLA kept sealed with desiccant, usually not.
What's the best all-rounder for WA?
PETG. It handles heat better than PLA, takes impact four times better, and copes with moisture. It's not UV-stable, so it isn't a full-sun material, but for most things it's the safe default.
Related guides
- PETG vs PLA+: which one for your part?
- Will ASA survive an Australian summer?
- Print temperatures for every Siddament filament
- Is PLA-CF actually stronger than PLA+?
We're a Siddament stockist based in Perth, Western Australia. If you're not sure which material suits a specific part, email us and describe what it has to do — that's a better question than which spool is on special.