Teardrops n Tiny Travel Trailers

Newbie Question?

Can you build an Aluminum Bolt Together Frame that will be strong enough and if yes, what size mateials should you use? What would be the weight savings?

I'm no structural engineer, but do you want it aluminum to lower the final towing weight? There are a bunch of bolt-together steel trailer kits that aren't real heavy, and that have actual rated loads that you can depend on.

Unless you've done this kind of thing before, the trailer would be the last thing I would want to experiment with.

mlhwild,

First, welcome to the forum. I know you will enjoy it and learn a lot while you're at it. At least, I know I have.

About the aluminum trailer frame, yes there is no reason that I know of why it couldn't be done. Don't know what size material you would need to use as I am not a mechanical engineer. I would think only slightly larger than what would be acceptable in steel, and most people that build their own frames prefer 2" X 1/8" square tubing. If you are going to do a bolt together frame, channel would be more pratical than tubing. I would think 3" channel would be strong enough for a teardrop frame in aluminum, but that is just an estimate on my part.

I would think, however that the weight savings would not justify the additional cost of an aluminum frame, but that is just a quess on my part as I have not priced aluminum structural material.

Why don't you get some prices on aluminum and let us know what you find out?

IraRat wrote
"Unless you've done this kind of thing before, the trailer would be the last thing I would want to experiment with."

Wow that's the last thing that I ever thought that I'd read on this forum. Bigger wheels, OK then smaller wheels. Move the whels back, no froward. Shorten the toung, nope legthen it. Let it over hang over the front, Naw, theback.

I accidentally bought 2 sticks of 2X2 1/8 aluminum, it was less than I paid for my steel. It could have been the vendor because the place I ended up getting the steel, is more willing to sell in small quantity. Steel comes in 24ft sticks and aluminum comes in 21ft.

An Ol Timer wrote:IraRat wrote
"Unless you've done this kind of thing before, the trailer would be the last thing I would want to experiment with."

Wow that's the last thing that I ever thought that I'd read on this forum. Bigger wheels, OK then smaller wheels. Move the whels back, no froward. Shorten the toung, nope legthen it. Let it over hang over the front, Naw, theback.

What are you shooting to become, Old Timer--the benficiary on their insurance policy?

Sorry for giving an OPINION. But for someone building their first tear, I would say it's pretty stupid to EXPERIMENT with the trailer.

An Ol Timer wrote:Wow that's the last thing that I ever thought that I'd read on this forum. Bigger wheels, OK then smaller wheels. Move the whels back, no froward. Shorten the toung, nope legthen it. Let it over hang over the front, Naw, theback.

Hey Ol Timer,
That sounds like someone narrating my design process...

the trailer would be the last thing I would want to experiment with

Hmmmm That's exactly what I did when I built mine!

IraRat wrote:What are you shooting to become, Old Timer--the benficiary on their insurance policy?

Sorry for giving an OPINION. But for someone building their first tear, I would say it's pretty stupid to EXPERIMENT with the trailer.

First, Maybe you should select better verbage, by saying that "it's pretty stupid to EXPERIMENT with the trailer" you could easily start a flame war. I've noticed that you do post with sarcasm, sarcasm does not usually translate very well in e-mails or postings. It is easily misinterpreted by the reader.

Second, I believe that most of us are already experimenting with our trailers. I welcome everybody to try different things. We can all benefit from this knowledge database. If something were truly dangerous, I'm sure that someone with knowledge or experience would chime in, look at the postings in the electrical section. When someone posted a schematic with a mistake, one of our electrical experts would point out the error.

Third, There are no steadfast rules that are written in stone. Even those using the KC plans do some things differently than others. They usually end up at the same destination, a beatuiful teardrop that they can camp in. There is no one way to do something.

I haven't welded very much aluminum, so I'm no expert, but my brother is...
When he and I built the glass rack for my shop truck, he talked me out of using aluminum, unless I wanted to bolt the entire thing together... Said aluminum welds would eventually fail because of the way glass racks are used.
I don't see that a bolt together aluminum teardrop frame would be a big experiment as long as you got some sound advice of what size profiles to use.
I too feel that experimentation is good... How do you think we got to the moon?

...I would have to agree with asian on most all his post. I am building on a custom made frame and it certainly took some experimentation to get what is probably way more frame than needed but what I wanted.
Since we had no plans our whole build has been one experiment after another and we still aren't done buildin' or sperimentin'.
madjack

TJ trailers has a plan available for a bolt together trailer which can be either aluminum (with SS bolts) or steel. Has anyone seen or used them?
Rod
http://www.tjtrailers.com/store/utility-bolt-together-trailer-plans-10x5.html

If you are trying to save weight, I would think that a bolted aluminum frame would cost a lot more, and not save much weight. Welds add little weight, were Stainless Steel hardware is heavy and expensive, not to mention that you will probably have to use a heavier guage aluminum than you would steel. You will still have a heavy steel axel, springs (unless you use a torsional axel) coupler, and safety chains.

If weight is the issue, you can build a steel trailer that a lot lighter than most of the ones built on this forum. Look at how commercial pop-up trailers are built, they use a minimum amount of steel, and last for years.

Here is the underside of a 1960's Apache pop-up that I have, notice how basic the frame is, and it is made of very light steel:



I plan on experimenting on a light weight trailer to pull behind our VW after I finish my current (and first) tear. Most people (myself included) build their trailer like they would a utility trailer, and don't take into consideration how much strength the body of the trailer adds to the whole unit (kind of like a unibody car vs the old full frame cars).

Jeff,
I noticed that too, when I went to the Dam Gathering.
I took a peek under a couple of factory built tears to look at the frame and I said, "What frame?"
I'm still proceeding on with my "Brinks AT" frame though, built like it was designed to hold three cords of wet madrone.

After exchanging emails with a teardropper, I decided to spend my break surfing teardrop sites. I'm a trailer type surfing through here--but the topic prompted me to respond.

I can document all-aluminimum body trailers to at least the 1930s (eg, Bowlus), they probably were made earlier. It's a form of construction also common in aircraft, so it is pretty strong. It's also how I understand Thor makes its T@B trailers. I don't know how it compares with construction costs with a wood body, but there's no reason why you shouldn't try for it.

That said, I don't think any of them have aluminum frames (trailers) on the bottom, so far as I know. They tend to be steel. Early trailers had wooden trailer frames, but again, I don't think there's any comparison to steel in strength. A rigid bed is necessary to prevent flexing, which could cause your teardrop to literally get ripped apart at the seams.

But above this, why the heck not go all-aluminum? It's much lighter than wood core construction. I'm airstream influenced, so my understanding comes from that form of construction. I'd still go for a proper steel frame trailer frame, decked with an appropriate marine ply (though I know some folks who are experimenting with decking made of the new plastic plywood thats out there now). Like most modern teardrop construction, I'd use a double wall construction, probably putting insulation in the core.

I'd start by attaching an aluminum U channel to the perimeter of the deck, attaching it with good hefty stainless bolts to the trailer frame. Then I'd shape the perimeter teardrop shaped frame with U channel, attach the outer, then the inner walls. For framing in the galley port (and maybe places where you hang cabinetry), you may want to use heavier metal for increased rigidity. Once you clad the inside and outside with aluminum, however, you will gain a huge amount of structural rigidity just from connecting the two layers with an internal aluminum frame (the U channels). BTW--structural aluminum like this can be ordered from Aircraft Spruce.

A couple of considerations--since you'd only be using aluminum, screws would not have any depth of material to gain purchase (like they would in wood). You'd have to use aluminum rivets instead. Without getting into a discussion of types of rivets (there's a whole story there), a big decision will be whether you will want to invest in a compression driven rivet tool. The manual ones are cheap and readily available, but remember, you'll be driving in hundreds of rivets, so that's a whole lot of cranking!

Another concern you must pay attention to is controlling a nasty thing called dissimilar metal corrosion. Basically, you don't want to have bare steel meet bare aluminum, because you will essentially start up a slow battery effect (no, it won't electrocute you, just corode everything). That means painting your steel frame with protective paint (like POR-15 or the ilk), using coated stainless bolts and sacrificial zinc washers.

Finally, you are looking to get a real shiny polish, you should use 2024 aluminum (aka, plated or alclad) for your exterior shell. This has a plating of purer aluminum on the surface, which will get much shinier if you put in the effort to polish it.

Mary