PETG vs ABS for 3D Printed Caravan & RV Parts

When choosing a material for 3D printed caravan or motorhome parts, the two most common options are PETG and ABS. Both are widely available filaments, but they perform very differently under Australian conditions — and the wrong choice can mean a part that fails within one season.

ABS has a theoretical heat resistance above 95°C, which sounds adequate — but that figure applies to unloaded, unfilled material in ideal conditions. Under mechanical load, in direct sunlight on a vehicle surface, the effective softening point drops considerably.

More critically, ABS degrades rapidly under UV. Australian UV index levels are among the highest in the world, and ABS parts left in outdoor exposure become chalky, brittle and prone to snapping within 12–24 months. For any part that sees sunlight — awning accessories, exterior brackets, window components — ABS is not a suitable material.

ABS is also brittle under the specific type of stress corrugated roads generate. High-frequency cyclic vibration causes crack propagation at stress concentration points, and ABS doesn't have the elongation at break needed to absorb those cycles without fracturing.

PETG was chosen for RV 3D parts because it matches what Australian roads and climate actually require. It maintains structural integrity in ambient cabin air up to 80°C — safe for all but the most extreme direct-sun surface temperatures. It resists UV degradation significantly better than ABS. And it absorbs vibration rather than cracking under repeated road stress.

The material is also chemically inert — it won't react with fuel, grey water, cleaning products, or the adhesives commonly used in RV fitouts. For a part that might end up near a diesel heater, a cassette toilet, or a gas fitting, this matters.

RV 3D pairs PETG with Solid-Core manufacturing — high density infill and multiple perimeter walls — which distributes mechanical load across the entire part cross-section rather than relying on thin outer walls. This is why RV 3D parts are often stronger than the factory originals they replace, despite being a different manufacturing process.

PLA is not suitable for any external or vehicle-interior RV use. It begins to deform above 60°C — which is below the temperature a closed Australian vehicle reaches in summer. PLA parts left in a caravan over summer will warp, sag or permanently deform. RV 3D does not use PLA for any functional parts.