[WerkSpace]

I was in the market for a 20' enclosed gooseneck trailer for my airplane project, vintage car restoration project, hovercraft project and maybe as a camping shelter, etc. You can never have too many projects.

I went to visit a few folks who had these trailers for sale but to my surprise, the empty weight was almost 5000lbs. I drive a 1996 Dodge Cummins diesel SRW pickup and would like to have an enclosed trailer with an empty weight of no more than 3500lbs. I looked around but nobody is selling such a creature.

So, I've decided to build my own. I started by purchasing a set of plans on eBay for $30 CAD.
http://www.southwestwheel.com/store/sho ... ans-mp2220

I will most likely use old mobile home axles with electric brakes ($100 each), a gooseneck ball type coupler ($100 eBay), a retractable gooseneck truck bed ball head and various other inexpensive bits and pieces that I collect from the metal recycling yards. (Steel is either 10 cents a pound or 30 cents a pound for structural.)

I was contemplating the thought of making a foam composite roof for light weight and insulation. The idea came to me, after looking at how light and strong surfboards were, when I visit Maui a couple of times each year. I think that the goal of a light weight cargo trailer is possible but will be a bit of a challenge.

I suppose the real fun will come when I try to register this trailer for highway use. I will visit the appropriate government agency before building anything, just so that I know what I am up against. It never hurts to figure things out before I get more than $30 invested in this idea.

[Otto Nobedder]

I've considered the same, with the goal of a travel trailer that weighed less than the commercially available units, so I could tow a larger one without upgrading my truck. I had assumed the majority of the weight would be in the frame, hitch, and suspension. I believe the lightest route is to create outer walls and roof from 1/8" marine-grade plywood, using the lightest-gauge steel studs I could find, on 24" centers. Any wiring should be run at this time. The plywood should be primed on the inside, and a commercial insulator hired to spray urethane foam in the stud-bays, and trim flush to the studs. Then the interior plywood (or decorative panelling, in my case) would be glued to the studs/exposed urethane, creating a nearly monocoque structure for the box. For exterior finish, I'd considered priming and painting the plywood, and covering with metal foil for the roof, and vinyl siding for the walls (as I've seen many modular homes tooling down the highway at 70 MPH, I assume it can be secured to be durable in high wind).

In the U.S., the requirements for a "home-build" trailer are not difficult to meet.

I'll be interested in what you arrive at, when you build this.

Steve S.

[WerkSpace]

Cedar strip canoes are pretty light weight. What if the entire cabin was made of cedar strips all glued in place with a thin layer of fiberglass cloth on top for weather protection? Think ultralight boats, only upside down.

http://www.bookworld.com.au/book/ultral ... g/1404921/

[Otto Nobedder]

Good point.

My thoughts on the subject were based on "living space", with an insulation value.

Not a consideration in a "cargo hauler".

[WerkSpace]

The real problem with a lot of the lighter materials is that they catch fire far too easily.
Whenever there is a trailer fire, you have literally minutes to get out of harms way.
Safety, Safety, Safety. The number one concern.

Finding fire proof materials is definitely a consideration.
As for insulation, I use Roxul in my garage and I love it.
http://www.roxul.com/home

[WerkSpace]

The plans for the gooseneck trailer project arrived from Texas yesterday,
...and so did the snow. We are expecting 6-8 inches today.

The trailer plans arrived in a cardboard tube and they are very large in size.
I briefly looked over the details and this trailer is designed to be light weight.

They start with a (5" X 3" angle) exterior frame with the horizontal flat across the bottom.
Then, they use (3" X 2" angle) inverted as the cross beams on 24" centers.
2" deck boards are attached to the upper flat portion of the cross beams to complete the 5" deck height.

The gooseneck portion is mostly comprised of 8" channel with 1/4" plate for fillets.
The dual axle CG centerline is 1/3 of the length of the deck from the rear, (not including the gooseneck.)
The 12,000 lb. single jack is located at the center front of the deck, (aft of the gooseneck.)

This version weighs 3,200 lbs empty and has a total capacity of 12,000 lbs.
The axles are 6,000 lb. each. I'm going to research electric over hydraulic brakes.
Mobile home axles are rated single use in Canada and have been discouraged by the transportation authorities.
With a total of 12,000 lbs for this trailer, I can understand why. (I've used them in the past on smaller trailers.)
The 38" ramps are designed to be stowed in the each side pocket of the aft portion of the trailer deck.
The deck is 6'6" wide, with the tires being outboard of the deck in order to make the deck lower to the ground.

If you wish to purchase these plans, they are available for $30 from here. So far, I recommend them.
http://www.southwestwheel.com/store/sho ... ans-mp2220

I've already started collecting materials for this project but don't expect to actually start it until the spring.
In the meantime, the hunt is on, for inexpensive materials from the metal recycling yards.
I am trying to budget $2,000 for this build. It seems a bit low, but I'm a very patient resource finder.
I've already acquired the vertical gooseneck trailer ball coupler for $50. It's brand new in good shape.
(My last 16' car hauler was built for $500 and sold for $3,000 five years later, when it was no longer required.)

[Otto Nobedder]

I'm sold on electric trailer brakes, for several reasons. They are reliable, especially if you apply aircraft standards to the wiring. The brake proportioning is adjustable for the load and conditions. Most electric brake controllers allow you to apply the trailer brakes manually, separately from the vehicle. With some parking-lot practice, you can learn to use the trailer brakes to correct a skid in slick conditions. And, it's simple to set up a "breakaway" device (required in many U.S. states on any trailer with brakes) to set the brakes in the event the trailer comes loose in an accident.

Sounds like you have a winner, at that estimated empty weight.

Steve S