Aluminum will heat up faster than steel, but will reach the same temperature if the outside coatings are the same. A light coloured surface will reflect more light than a dark surface and absorb less heat. An insulated surface will initially not change temperature as quickly as an uninsulated surface, but over time the two will even out. A bare aluminum trailer reflects a great deal of light, a painted steel will absorb more even if painted white. 

The stock trailers have larger cooling vents than closed horse trailers and offer more ventilation. The white painted roof on our old steel stock trailer  got very hot in the summer. One of our aluminum trailers has an insulated roof in the stall area, the other does not. By midday there is no discernable difference in the stall temperatures.

We are now switched to aluminum trailers and have no plans to change. The overall maintenance on the aluminum is drastically less. One of our trailers is almost ten years old and looks like new. Our steel trailers were never able to be maintained in a new looking condition, even after an involved complete repaint.

The area in which you live, will dictate which long term trailer ownership is most apropos; rust belt or dry and arid. IE, aluminum or steel.

Gard

We're in NE Georgia, not near the coast, but hot and humid in the summer.  No salt on the roads from winter icing.  Just seems like the stock trailers now have hardly any openings in them, i.e. just two small slat openings high up, used to be a lot more open with good air flow.

This is the trailer I have. Bought it new in Jan. 2000. Have been real happy with it. Wish I got a 4 horse though. Price was right.

http://www.horsetrailerworld.com/home/trailerdetail.asp?ID=150999

I've had both steel and Aluminum gooseneck trailers. My only complaint with steel is the rust issues here in Oregon where I live, Hell even I rust around here!

 This last time around I bought an all aluminum Exiss Event LQ , which is a less expensive aluminum trailer than some. I like it fine no problems, pulls good. I thought about the steel frame alum skin trailers like Kiefer or Logan as I shopped , and I would recommend that as a good option as well. As for steel trailers...Trails west, is the best for the money in my opinion.

Even though I didn't start this post, I wanted to thank everyone who took the time to respond....I am actually in the same situation as the person who first posed the question.  I want a aluminum trailer to avoid rusting, but kept hearing how hot aluminum trailers are.  If I understand this right, it seems the aluminum trailers heat up faster, but the end temp. is the same between steel and aluminum?  Great idea adding a fan...is it battery or tied into the trailer wiring somehow?

Aluminium vs. steel with regards to heat..interesting topic, and I do not think it has been addressed on this forum before. Another consideration, whether your trailer is aluminium or steel is air flow. I found a huge difference in the horse area when I went from a 7' to a 7'6" trailer height and an 8' width. Lots of opportunity for air flow all around them. My horses range from 15.1 to 16.2 in height. I also have air vents overhead, bus windows at the sides, small ones on doors to the horses' heads and on the rear doors, as well as in front of the horses. I then open the bus windows on the sides of the dressing room, small dressing room door bus window, and roof of dressing room vent. Lots of indirect air flow. It is a 2 horse straight load steel trailer, and I do not travel with the drop down windows dropped. Horses are comfortable, even on the most hot and humid days.

Brenda 

If you want to know about steel/galvanneal skin trailers, look at the posting under BEE trailers. There is a very informative photo that should answer many questions about the longevity of steel trailers.

Gard

You are absolutely correct. There are thousands of "formulas" that determine what ingredients are used in the manufacture of steel. Each type of steel is usually established by its intended usage.

However, many manufacturers buy ready made products based on cost. For instance, a certain type of steel may be based on the lower grade products, from the commercial boats being scrapped in India. There they use open hearth furnaces, and the melds are mixed with many alloys from any available source. Or it could be a high grade ingot, formed in vacuum furnaces, such as found in upstate, NY. There steel is made for the aerospace industry under the most exacting of circumstances.

What steel the trailer manufacturer uses and how much, will greatly contribute to its strength and usefulness.

Where the trailer is used is as important to its longevity as is its maintenance and care.

I've also had several steel trailers, the last one for a dozen or so years. When I sold it, it had no structural issues. It was never stored indoors. I sold it for about a thousand less than I paid for it. But I also spent $3000 and two weeks of my labours in a restoration to save it from a rusty ruin.

I now have aluminum trailers. I wish when I first started supporting my wife's hobby, that we had the money to buy an aluminum trailer. In my circumstance, the maintenance is a small percentage of steel, the long term attractiveness is far superior, and my resulting pride of ownership is much greater.

My aluminum trailers are also scheduled to be life time investments; there are no plans for any substitutions. I am pleased that this is where I am, at this point in my life. My only regret is not being able to purchase these trailers earlier. I wish I could have done it sooner.

Gard

Here are interesting linksthat relate to Gard's post in some ways and illustrates the problems with man-made steels:

http://www.corrosion-doctors.org/Bridges/Silver-Bridge.htm

http://www.open2.net/sciencetechnologynature/worldaroundus/silverbridge_partone.html

Stress, cracks and corrosion. Sounds familiar.

 CRG, your research is very relevant to our topic.

Yes,well,see how just a tiny little unnoticed crack caused the death of 46 people?

I'll rephrase the statement to say "contributed" instead of caused.

No matter what,46 people died because something went unnoticed.I was just trying to say what appears has been missed,kind of like not seeing the forest for the trees.Anybody from West Virginia or East Ohio remember this incident? 

Well I read the article and come away with something much different than a crack causing the demise of those folks.

"Another major factor that helped corrosion fatigue and stress corrosion in bringing down the bridge was the weight of new cars and trucks. When the bridge was designed, the design vehicle used was the model-T Ford, which had an approximate weight of less than 1,500 pounds. In 1967, the average family car weighed 4,000 pounds or more. In 1928, West Virginia law prohibited the operation of any vehicle whose gross weight, including its load, was more than 20,000 pounds. In 1967, the weight limit almost tripled to 60,800 pounds gross, and up to 70,000 with special permits. Civil engineers must use a projected life span for nearly all projects, but no one could see that 40 years after the construction of the Silver Bridge that traffic loads would more than triple. "

I quess that goes to show that there are most likely to be much different opinions to the same article. You two seem to think a crack brought down the bridge. I think it being overloaded brought down the bridge.

I would quess you all would think that if I have wreck doing 80 mph and my trailer comes off the ball and kills me, that not having the safety chains hooked up is why I died? I would argue that driving 80 mph is why I died. Two sides to the same story.

I have had about all the fun I can stand on this stuff.

I'm not an engineer nor profess to be an expert,but,I've read and talked with people at Point Pleasant and watched everything I could about The Silver Bridge,and,the experts all conclude that a fracture in the eyebar when it was cast eventually led to the collapse of the bridge.PLUS the load of the newer vehicles.It was both,but,if it hadn't had the eyebar crack,it probably would have still been standing.That is what is the general concession.

Don't take MY word for it,tho,you can contact the folks at the Point Pleasant River Museum yourself,and ask them,
Hey,I just wondered,what caused the bridge to fall?

CRG - I won't argue that the cracks caused the failure, but what I got out of it said that the cracks had multiple causes. Stress corrosion cracking, corrosion fatigue, and failure to use the bridge in the manner that is was designed...triple the intended weight load.

HWB - Do you feel like one of those ducks in a duck gallery at the fair?

They ain't getting close enough to worry yet.

So bascially what we are saying is that if you dont have enough sense to maintain your steel trailer then buy aluminum because it doesnt rust????

I take no less "pride" in my steel trailer than I would an aluminum, rust is technically not an issue here (although unpainted metal will still rust), nor was money, I still chose steel. We recently had a friend finally get her "dream" trailer, an aluminum Featherlite 2H BP. Her dreams came crashing down around her when, after taking delivery, she found out it was not recommended to use her WDH on the aluminum tongue.

There is no reason a steel trailer will not last a "lifetime" if properly maintained, even in the rust belt. These 'new' galvanneal skinned trailers will make this much easier. 

  Quote: aluminum Featherlite 2H BP. Her dreams came crashing down around her when, after taking delivery, she found out it was not recommended to use her WDH on the aluminum tongue.

 Don't think I have seen a bumper pull trailer with an aluminum tongue!!! I imagine that the WDH clamps would dig into that like it was made of wax!!

I didnt verify it, only passing on what she told me...............

Gard,

Attractiveness and pride of ownership are important. However, as they say, "beauty is in the eye of the beholder." I, too, in my younger days, had to more closely watch the dollars spent on a trailer. I have continued to select steel because that was what I wanted. I am very proud of my trailer, and it's attractiveness. Brenda

I did not mean to imply that steel trailers are not attractive and cannot be held in high esteem. They certainly are both. You should be proud of whatever you have purchased. It took time, money and decision to effect your purchase. I'm sure that your efforts were not an easy process.

I've previously made the statement " everything I own is disliked by someone else". If I were to own my possessions, based solely on someone else's opinion, I would have nothing. Pride of ownership, can be gleaned from the first used rust bucket, to the top of the line mega trailer. Beauty is in the eye of the beholder.

St. Thomas Aquinas describes beauty "As that which gives pleasure." If you gain pleasure from its usage, then it is beautiful indeed. And of that you can be very proud.

Everyone's particular circumstances vary. What is best for me, obviously is not the best for you. That does not make your's or mine ownership any less valuable. I wish you many happy year's of trailering.

BOL  Gard