Aluminum vs steel car trailer: Which should I buy?

In the market for a replacement car hauler.   I've owned a steel Challenger trailer for the past 15 years and it has been great and trouble free.  I tow my fun play cars occasionally (Miata, RX8) and the rest of the time I tow cars for a charity I volunteer for (corollas to midsize suvs).  I'm either pulling with a 100 series Land Cruiser or a diesel Ram pickup and they both tow well.  
 

It stays outside ( but in the shade).   I also have a winch i mount in case.   So for the same price, do I:  

1.  Buy a steel trailer like the one that has served me so well brand new.  
2.  Buy a used aluminum trailer (maybe even with a tilt) although my ramps have served me well and I don't mind them.    Pictures below of one like my current one and an Aluma one that I found online.  
 

Since it lives outside I would vote for aluminum.

Really?  I would think steel.  Aluminum can corrode like nobody's business.  You should see some box trucks I have seen.

I've only got second hand experience with this, but would like to share one thing that I read about aluminum trailers. Hopefully someone else with experience can clarify.

There's a choice of welded construction or bolted. I read that the welding makes the aluminum brittle and prone to cracking, making the welded aluminum trailers a poor choice. 

I have owned an aluminum Trailex (bolted) trailer for 20+ years. My friend bought it new in 1984. I love it. It lives outside, and with a power washing or some Zep Alum, it will look new-ish in no time. I think it weighs less than 900 pounds. 

Why are you replacing yours??  If it just looks bad, I'd consider having it painted (or painting it yourself), maybe refreshing the bearings and keeping it for many more years. 
 

if you must replace, advantage of steel is that you can weld things to it easily. 
 

I wouldn't worry about the welded aluminum trailers - unless they're done badly.  A good inspection should reveal any issues. 
 

lastly a tilt isn't bad but I had a rollback for a minute but after having it get tweaked and not work right with a car half-loaded I decided that I, personally, didn't want a trailer that could give me problems.  I'll leave that to the race car and the tow vehicle.  I don't want to wonder if something is going to break on my trailer too. 

Generally I see steel trailers rust worse than aluminum trailers corrode.  But at the same time, aluminum does have a finite fatigue life.  If the trailer build is heavy-duty enough, it'll take a long time for fatigue to become an issue, but it does mean that the steel trailer will theoretically last longer.  And steel is generally cheaper.  So if weight matters, go aluminum, but if not, I'd definitely consider sticking with steel unless the trailer models you find in each material mean that the better trailer (for other reasons) happens to be made of aluminum. 

Floating Doc (Forum Supporter) said:

There's a choice of welded construction or bolted. I read that the welding makes the aluminum brittle and prone to cracking, making the welded aluminum trailers a poor choice. 

AIUI, the issue with welded aluminum trailers is that welding aluminum anneals it and removes the heat treatment.  This makes it weaker, and since nobody has an oven big enough for the entire trailer that means it needs more material.  So a welded aluminum trailer doesn't wind up being all that much lighter than a steel one of similar size.

Bolted aluminum trailers are made of heat treated components that haven't been annealed, and so can be significantly lighter.

As for which to buy, for an open trailer I would go steel.  Aluminum trailers are a lot more expensive than steel ones and I think you wind up better off overall by putting that money into a stronger tow vehicle than into a slightly lighter trailer.  I can't speak to rust, I live in California. 

My steel trailer has sat outside for 27 years. The fenders have holes rusted through but the frame and decking are still solid. New fenders and a paint job and it's good for many more years. Aluminum only if you need lightness or have money to burn.

Are you going to use the trailer for other things ?
 

I would think  a utility trailer with pockets for stake sides  would  make it more useful.

I just find that I use my utility trailer for a lot more than moving cars......

An 18 wheeler decided he wanted to try and climb up my trailer while driving down the highway :/.   I received a healthy insurance check from them so that is why I am shopping.  It could be fixable but I'm not sure I want to worry about the structure or safety while towing which is why I'm leaning towards replacing it and letting someone else fix this.   The axle came up and dented the frame so that is also a concern.  

The aluminum trucks I have seen with heavy corrosion all started where they were bolted/riveted together.  Make of that what you will.

There WAS a company that built welded aluminum trailers from huge extrusions that they had made for them, and IIRC did have an oven large enough for the processes needed after welding together large pieces of aluminum, but they charged dearly and are out of business anyway.

Since we're talking trailers, I'll jump in with a question or two:

Is it worth it to try and modify a basic utility trailer (16', angle iron frame, wood deck) to use a vehicle hauler trailer? By modify, I mean removing the side rails and adding bracing and an additional 10" wide board on each side to make it wide enough to get a vehicle that measures 84" wide on it. Most flatbed car haulers I've seen are 83" wide, but my '71 Bronco (with full-width axles and 35x12.50x15 tires is exactly 7 feet (84") wide at the outer tires sidewalls - it won't fit between the side rails or inner fenders of my utility trailer.

Sure, I could just buy a generic car hauler trailer, but I'd still have to drive over the fenders of the trailer with the front tires of the Bronco to get it on there. My utility trailer needed a new wood deck, so I removed the old rotten wood and got a good look at the frame, it's in good shape, that's what got me thinking about modifying it. I know buying a dedicated vehicle hauler trailer is the no brainer answer, but it just seems wrong to have 2 trailers that are so similar (plus the extra tires, plates, etc).

OP, are you in Texas? If you're selling that bent trailer, I might be interested...   

I've never had an aluminum trailer, so I can't comment on that. 
 

It sounds like you haul cars frequently. The tilt bed might be pretty nice. 

I'd get the steel trailer. I love mine. its actually pretty light and easy to tow. I would avoid wood decks. 
 

https://www.carsontrailer.com/trailers/car-haulers/california/

Dad's steel flatbed that I constantly borrow for everything is bulletproof.  It's only modestly heavier than a comparable aluminum one but it is very strong.  It lives in the salt belt and it is now 25(?) years old.  Of course it has rust, but when you're starting with 1/8" thick 2" x 4" c-channel, it can have a LOT of rust before it's weakened.  It lives outside 24/7.  The only time it's in the garage is for bearings or brakes.  Sometimes it has weeds growing up through the deck.  Impossible to kill.  It's due for its first repaint and a new wood deck.  We plan on pulling the old lumber off, flipping it up, hit it with the steam genny, and slather on some POR15.

I almost bought an aluminum trailer when I lived in CA for weight savings, but it only saved me about 300 lbs and I knew it would look like trash in a few years.  Aluminum trailer was $10k.  Steel trailer was $7k. (these are old prices, but just for comparison)

Plus, the aluminum trailers I've owned have been really floppy.  Not that it's a bad thing from an engineering standpoint, but metal (especially aluminum) can only bend so many times before it tears/cracks.  Just rubs me the wrong way.

Aluminum is exotic, steel is strong.  If I won a million dollars today, I would get a steel trailer and bank the rest.  For me, aluminum isn't an upgrade when it comes to trailers.

Steel here. Since I like to periodically modify my trailer (tire racks, spare tire mounts, winch mounts, or whatever I feel like at any given time), I prefer the flexibility to easily weld stuff on with my MIG. 

We have between ten and fifteen aluminum trailers at work. As well a handful of steel goosenecks.  We buy and sell a few each year. 

Once a year they get serviced, mostly repacking wheel bearings,adjusting brakes, and fixing frayed wires.

The oldest aluminum trailer I usually see is from around 2011. Most have a few small cracks around factory welds. I grind out the cracks and use the spool gun to make everything one piece again. 

They see around ten thousand miles a year each. If they haven’t hit anything it’s usually not a big deal. Two or three welds per trailer. Cracks happen just outside of the factory welds. I haven’t needed to Reweld a joint  that has been previously repaired. 

My steel trailer is made of 2x4 tubing, not C-channel. I wonder if it makes much difference in weight or rigidity.

Looks like steel is winning here.  I actually still really like my trailer.   Going to talk to my body friend see what he thinks next week about fixing mine and being safe.   That's the most economical option.   

codrus (Forum Supporter) said: ​​​​​nobody has an oven big enough for the entire trailer 

I do, but technically it's a furnace and not an oven. More importantly a run that fits 3, 4 or maybe 5  trailer bodies will cost about the price of a decent used one, so that's hardly economical.

I don't have a good vote about steel or aluminum. Less weight is always a bonus, and it's not like you'd have to deal with rust belt levels of salt in Texas. My enclosed trailer is an aluminum floor on a steel frame, so clearly both is the right answer.

It's too bad that a bent sheet aluminum trailer isn't available anymore- mine is about 25 years old and there are no issues with the AL. 
 

The big issue is the last one was built about 20 years ago. 

But for the small car crowd, it being short and 700lb makes it a pretty amazing trailer. 

In reply to alfadriver :

Size matters. If I were starting over I would buy/build a smaller trailer,sized to the small cars I've always raced (Miata & GTI). One like yours would be ideal. My first trailer.....10 foot car on a 10 foot deck, towed behind a Pontiac 6000.

In reply to alfadriver :

What is a bent sheet trailer?

In reply to Floating Doc (Forum Supporter) :

The tread plates are folded 1/8 aluminum plate and function as the longitudinal members of the frame. Suspension and cross members bolt to the tread plates. It's pretty damned clever design. I've seen pictures Alfadriver has posted here before. Maybe he'll post them again.