Can I just paint ABS to protect it from UV?

Yes — a good 2-pack automotive paint will protect ABS outdoors. But if you want a bare plastic finish, choose ASA from the start.

Is ASA more expensive than ABS?

Slightly — usually 10–20% more per kilo of filament. On most parts the price difference is a couple of dollars.

What about PETG for outdoors?

PETG is fine for short to medium outdoor exposure but doesn't match ASA's long-term UV stability. For a part you want to install and forget, ASA is the safer pick.

ABS vs ASA for Outdoor Parts

ABS vs ASA filament for outdoor 3D printed parts — UV resistance, weather, strength and which to choose for Australian conditions.

If you need a 3D printed part to live outside in Australia — on a roof rack, a caravan, a boat, a letterbox, a garden irrigation system — you have essentially two strong choices: ABS and ASA. They are chemically similar, print similarly, and look almost identical. The difference is what happens after a year in the sun.

What are ABS and ASA?

ABS (acrylonitrile butadiene styrene) is the classic engineering plastic used in LEGO bricks, car interior trim and electronics housings. It's tough, machinable, glueable with acetone and dimensionally stable up to around 100 °C.

ASA (acrylonitrile styrene acrylate) is essentially ABS with the butadiene replaced by an acrylate rubber. That single change makes it dramatically more UV-stable. It was originally developed for outdoor automotive trim and signage.

UV and weather — the decisive factor

ABS yellows, chalks and becomes brittle after sustained UV exposure. In Adelaide, Perth or anywhere north of Brisbane, an unpainted ABS part can show colour shift within a few months and surface crazing within a year.

ASA is engineered to resist exactly this. Outdoor signage made from ASA holds its colour and toughness for 5–10 years. For any unpainted outdoor part in Australia, ASA is the right answer.

Strength and temperature

Both materials handle 90–100 °C without softening — far better than PLA or PETG. Tensile strength is similar (around 40 MPa) and both are tough and impact-resistant. ASA is marginally tougher in cold weather, ABS marginally easier to acetone-smooth.

Printing

Both need an enclosed printer to avoid warping and cracking, and both emit styrene fumes — your maker will print them in a vented enclosure. Expect a small price premium over PLA/PETG (typically 20–40%) because the print is slower and the failure rate is higher.

When to pick which

Pick ASA for: outdoor brackets, antenna mounts, caravan and boat parts, garden hose fittings, letterboxes, anything that will live in direct Australian sun.

Pick ABS for: indoor enclosures, electronics housings, automotive interior trim, parts you plan to acetone-smooth or paint, anything that won't see direct sun.