A custom trailer is a set of materials pretending to be a vehicle. These pieces walk through steel versus aluminium, hot-dip galvanising versus powder coat, drawbar geometry, floors that drain, and looms that still work after a Cape York wet.
Outback trailer wiring fails at earths, junctions and abrasion, not at the globe. Route the loom for corrugations, specify the plug, and give yourself a field repair.
Trailer floors fail from trapped water and tired fasteners more than from the deck material. Choose chequer, timber or composite for drainage and replacement, not for the photo.
Profile choice and drawbar geometry decide fatigue life on Australian corrugations. Heavier steel is not a design. Drain paths, joints and ball height are the job.
Zinc is sacrificial, powder is a barrier. Australian trailers fail when those jobs are confused, when boxed steel cannot drain, and when a pretty coat hides mill scale.
Material choice is climate, duty and who can weld it on a Tuesday, not a weight slogan. Steel and aluminium fail in different Australian ways, and mixed metals fail faster.