Tow The Line: Should You Choose Steel Or Aluminium For Your Custom Trailer?

Posted on: 19 October 2016

Having a trailer manufactured to your specifications by a metal fabrication company is one of the best ways to ensure that your new trailer suits your particular needs. However, you will have a number of challenging choices to make when specifying your new trailers design and configuration, and one of the most difficult choices to make is which type of metal it should be made from.

The vast majority of custom trailers are made from either steel or aluminium, and the debate over which is best seems to rage eternally. However, steel and aluminium both have very distinct advantages and disadvantages when it comes to trailer building, so it's important to thoroughly analyse their pros and cons before deciding which is best suited to your towing needs.

What are the advantages of choosing steel?

  • Price: Steel is both less expensive and more readily available than aluminium, giving you lower quotes and a wider variety of metal fabrication outfits to choose from.
  • Rigidity: While both metals are far from what most would consider 'flexible', aluminium is more flexible than steel and can flex and bend over rough roads, Steel trailers are therefore prized for being able to tolerate rough ground without significant distortion.
  • Strength: Steel's maximum strength is significantly greater than aluminium, making steel the metal of choice for high-capacity trailers expected to carry heavy loads.
  • Inexpensive repairs: Steel trailers are also less expensive to repair than aluminium trailers, due to the comparative ease of welding steel and the low price of replacement materials.

What about the disadvantages?

  • Corrosion: This is the chief problem with choosing steel, and many trailer owners choose aluminium simply because it has little propensity to rust. Steel trailers can nonetheless be protected from rust using protective coatings (galvanised and baked powder coatings are popular and effective choices), but these coatings can be expensive to apply and will need periodic renewal.
  • Weight: A steel trailer will weight significantly more than a comparatively sized aluminium trailer, entailing higher fuel costs and increased wear on your towing vehicle's tyres. 

What are the advantages of choosing aluminium?

  • Corrosion resistance: Aluminium is naturally high resistant to corrosion, due to the layer of inert aluminium oxide which builds up on its surface over time. It is also less prone to staining as a result of oil and fuel spills, giving you a new-looking trailer for longer.
  • Lower maintenance costs: This corrosion resistance also means that an aluminium trailer will be cheaper to use over the long haul, since it requires no protective coatings that will need renewing.
  • Light weight: As previously mentioned, aluminium trailers are much lighter than steel alternatives. This decreased weight also gives you a higher maximum payload capacity before your trailer becomes too overloaded to tow, so aluminium trailers can be an excellent choice for towing vehicles with limited torque.
  • Higher resale value: If you decide to sell your trailer once you have no more use for it, you're likely to fetch a higher asking price for an aluminium trailer than a steel one. This is largely due to hidden corrosion not being a problem with aluminium, but is also due to aluminium's value as scrap metal.

And the disadvantages?

  • Higher prices: The increased value of aluminium over steel unfortunately translates to higher fabrication costs, which are exacerbated due to the increased difficulty of working with aluminium. They can also take significantly longer to fabricate, increasing labour costs.
  • Difficulty repairing structural damage: If your trailer suffers structural damage, for instance to the chassis or side sills, repairing it yourself can be extremely difficult without the specialised knowledge and equipment required to weld aluminium. As such, aluminium will usually need to be repaired professionally, which can be very expensive for larger trailers.