Why do many of the large, well known horse trailer manufacturers such as Sooner, Sundowner, Featherlite, Four Star, and Exxiss, build horse trailers with all-aluminum frames, walls, roofs and interior dividers, whereas others such as EquiSpirit, Double D, Trail-et, Hawk, Bee, use mostly steel, and/or a combination of both?
I believe the answer lies, not so much in benefits of one over the other, but in the history and development of the horse trailer industry itself.
Back in the late seventies and early eighties, horse trailer manufacturers such as Sooner Trailers, Featherlite horse trailers, and Four Star horse trailers, began searching for alternate materials to replace steel since steel horse trailers were quickly deteriorating from rust. Since rusted horse trailers were generally everywhere horse trailer owners went, it didn't take much to convince consumers to switch to something better.
After many materials were considered - Sooner and Merhow trailers had built some of their horse trailer models with a product called FRP (fiberglass-reinforced plywood). Others such as Bison Horse Trailers experimented with all fiberglass - aluminum was the ultimate chosen material, and all-aluminum trailers quickly grew.
What horse owners didn't know were the negatives and dangers of using aluminum in the frame, sidewalls, floor and roof - that it was a more brittle material, would shear and tear when stressed beyond its capacity, and that it conducted heat. These negatives were not readily apparent, and the ability to research construction materials of horse trailers was not as easy as it is now. What most consumers basically did know about aluminum was that it didn't rust - and that seemed to be enough.
One of the negatives that was apparent to the manufacturers, and worried them, was the high cost of aluminum. However, the high costs eventually worked in their favor - the market was ready to spend more for a supposedly better product, and the high cost gave consumers the impression that it was a superior trailer. It costs a lot more therefore, it must be better.
Once the "all-aluminum" horse trailers hit the market full force, the market quickly perceived that the all-aluminum trailer was a high quality, premium product. Therefore, horse trailers such as the models built by Sooner trailer manufacturing, Featherlite trailers, and Four Star trailers were perceived as being top of the line, not realizing that the extra expense was directly attributed to the higher cost of aluminum, not necessarily, because it was a better product. Because of this consumer perception, combined with the rapid market acceptance of the all-aluminum trailer, and the alternative being rusting steel, many existing manufacturers switched over to aluminun, such as Sundowner, Merhow, Cherokee, and Bison. Through the years, many new start ups opted to build all-aluminum horse trailers such as Exiss, Eby, Adam, and Gore for the same reasons.
Of course, it is true that all-aluminum trailers are not equal - some are better than others are. Companies such as Sooner, Featherlite, Exiss, and Four Star will vary in quality and design according to the company's construction and design philosophy. The real issues to look at are the problems inherent in the aluminum material itself.
Pound for pound, aluminum used in most horse trailers is only 1/3 the strength of steel, so when it is used in the frame, this has to be taken into account. Manufacturers often have to boost the amount of aluminum used in the horse trailer floor and frame to get the equal strength of a steel frame. This is why some of your better "all-aluminum horse trailers, such as 4 Star, will be the same weight, or sometimes heavier as a similar model steel built trailer. Where aluminum often fails the consumer and their horses is in the interior dividers. Since aluminum is weaker by about a 1/3 from that of an "equal in size" steel divider, it will fail quicker under stress. When aluminum fails, it shears and tears.
This creates a danger of minor to major lacerations to horses, often occurring from relatively minor mishaps, such as severe braking, or swerving to avoid hitting something. Aluminum is also a good conductor of heat - it makes good cookware. Keeping horses in a comfortable, controlled environment in a trailer with aluminum floor, sidewalls, and roof is a real problem, especially on hot days. Repair issues are also difficult since aluminum is not only difficult to weld, welds can never be re-welded to their original strength.
Some of the major "all-aluminum" manufacturers that I have mentioned - Featherlite, Sooner, Sundowner, Exiss, Eby have now been around long enough that they have vastly improved their manufacturing process, and thus, their trailers. However, the aluminum trailers have also been around long enough, that consumers are now seeing aluminum floor deterioration from the alkaline in urine and manure - a direct result from not cleaning. They have also directly experienced the heat problems, and are seeing the broken welds, and torn aluminum on fenders, running boards, ramps, and dividers.
So what's the alternative?
Because of the demands placed on steel from the auto industry, it's little surprise that almost all the rust problems with steel have been eliminated. Since rust is what originally started the crossover to aluminum, Galvaneeled steel, galvanized steel, powder coated steel, and other new technologies, are now available as a viable, and better alternative. Besides adding strength and protection for the horses, steel is still less expensive than aluminum, and is easy to use, and repair.
Since consumers have more access to information today from many sources, but particularly the internet, they are realizing that if the car industry is surrounding drivers and passengers in a highly protective steel cage, and steel body, why should their horses not get the same protection. Consumers are also seeing very little, if any, rusting in automobiles over the last ten years. Processes such as undercoating and Z-Bart rust protection on cars, have all but disappeared.
So why are all-aluminum trailers still being built?
It would be highly difficult and much too costly from both a manufacturing and marketing standpoint for the larger horse trailer manufacturers to just quit, or change over. In addition, the horse trailer manufacturers have done such a good job over the last twenty years of convincing consumers that all-aluminum is first class, that it will take some time for horse trailer owners to form a new mind-set about what they have believed. But the market is dwindling, and horse trailer manufacturers will surely have to change their thinking if they want to survive.
So where is the market headed?
For one thing, quality built, all steel trailers are having a resurgence. Those steel manufacturers that have hung in there over the years are seeing new growth in sales.
It's my belief that the future of horse trailer manufacturing will be in what I call, the composite-built trailer - using a variety of today's technologically advanced materials. Galvanized steel (dipped protected against rust), galvaneel steel (electrochemically treated against rust), power coated steel (baked against rust), fiberglass, and a variety of new products that are appearing on the market every year.
We, at EquiSpirit, follow the safety ideas of the auto industry by building a steel (non-rust) cage around the horses. This includes galvaneel side walls, steel roll bars molded into the fiberglass roof, galvanized steel frame, solid steel doors in the rear with a ramp over the doors, aluminum used in a non-structure skin siding, powder coated steel in all dividers, and insulation throughout the dual walls.