Here are some facts to think about. In the end, it all adds up to personal preference.
1. There will be very little weight difference between a quality, well made aluminum trailer and a steel trailer.
2. Aluminium is far more expensive and aluminum prices go up all the time.
3. Steel will rust in time …. Aluminum will oxidize – same thing.
4. Aluminum cannot contact steel, so an insulating tape has to be applied between the aluminum body and the steel axles and frame work for the axles. Also, the coupler assembly has to be steel and that is a problem for aluminum to come in contact with a steel coupler.
5. Steel is stronger, takes punishment better than aluminum. In case of an accident, a horse has a higher rate of success surviving a crash than in an aluminum trailer.
6. Aluminum welds do not have the strength of steel welds.
7. Steel is easily painted a broad range of colours. Aluminum has to be ordered in huge lots all in one colour. It is expensive to order a coloured aluminum trailer.
8. Aluminum trailers need to be “acid washed” every year or so to keep them clean. Once you acid wash an aluminum trailer, it takes a lot of the luster and sheen away. You can always tell from that day forward, that the trailer was acid washed. A steel trailer can be washed weekly as you would your own car and it always looks fresh. Steel is less maintenance.
9. Modifications are easily done to a steel trailer. An aluminum trailer is limited to modifications after you purchase it because it is difficult to weld, or you have to drill holes to rivet it or bolt it. Everytime you drill a hole in aliminum and insert a bolt or rivet, you create a potential water leak. The holes start to round out due to vibrations during use.