WOOD vs. METAL Trailer Wall Construction

[Titanpat57]

So much to be learned from so many talented people...ok, so let's have at it...

In this corner...weighing in at a svelt....oh, nevermind..

Currently, we have two separate points of view, wood vs. metal, by design, and structural strength, I think it's fair to say that both have have their advantages, but why?....

I would like this to be a civil venue for experienced as well as inexperienced newcomers, to read, understand, possibly seek help, and most of all, relate to, the forces that are applied to trailer wall construction due to differing trail condition, factored with speed, etc., etc.

We have much to gain, and I appreciate any input.

 

[adventureduo]

Thank you TitanPat for starting a new post as this should prove to be an interesting thread.

 

[TangoBlue]

Well done!

Let's talk about something completely different now...

 

[Titanpat57]

Well done!

Let's talk about something completely different now...

lol...ok!

howdy TB!

 

[Yellowkayak]

What is comes down to is MONEY. Both materials can be shaped and cut to any shape you want if you have the right tools (this is the money I'm talking about). For a trailer I'd think you would want light weight but heavy duty.

WOOD

Pros - easy to cut and relatively cheap, can get some good shapes out of it
Cons - Suseptable to water instrusion and will rot or fall apart, and not to mention weight (heavy)

METAL

Pros - very durable, can take alot of abuse can be cut easily with the RIGHT EXPENSIVE TOOLS, lighter weight than wood of the same size
Cons - cost (higher), rust if paint is nicked or chipped

If I had the money to buy a good plasma cutter to get good even straight lines, I'd go with the metal for sure, and get a good powder coating on all surfaces...even hidden surfaces.

JJ

 

[GroupSe7en]

Metal would include aluminum as well as the various kinds of steel.

If you live near the coast, you can get it bent and welded at any of the shops that make towers and awnings for boats - cheaper than you might expect.

You'd get a strong and l i g h t frame for not a ton of cash - worth considering.

Interesting thread - thanks for starting it.

Cheers,
Mark

 

[Woods]

Both - My box is constructed using thin aluminum sheeting over an aluminum frame. I'm going to laminate a thin wood panel to the inside of all aluminum sheet. The thin aluminum sheet is susceptible to dings and dents. The wood will help greatly with this. Check out how large truck trailers and motor homes are made. They usually use thin sheet over a frame then do wood for protection on the inside.

 

[ntsqd]

If you introduce both boat and light aircraft building techniques then wood can have a significant weight advantage over metals. If you include wood in a quasi-composite type of build then the weight advantage increases a bit more and the stiffness/rigidity of the structure will also increase while potentially also addressing the moisture vs. wood concerns.

If you build with wood like you're building a house then longevity is a real concern.

 

[JPK]

Aluminum is very susceptible to fatigue, wood is not.

ntsqd has it right.

See this sight for more information (the site is a pita to navigate but there is a TON on information to be had http://www.gougeon.com/

And more specifically: http://www.westsystem.com/ss/how-to-use/

 

[bob]

My feelings on a steel frame have been stated.

I am looking at aluminum upper frame. Can not afford to build lower frame out of aluminum. Plus I have the fear of it breaking. The problem with upper walled aluminum is that it must be attached to the steel frame with wood. Basically the Trailer industry uses a aluminum frame molded into styrofoam and then laminated luan to the outer and inside wall. The thickness is approximatel 1 inch of aluminum tube and foam, 1/8 luan on each side and 1/8 fiberglass on the outside. The fiberglass and the 1/8 luan give the trailer strength, by lamination, bolts and screws. You can not attach aluminum directly to steel. So the walls have a 1 1/2 inch wood runner on the bottoms and are lagged to the steel frame. This worries me in our use. Wood at the base attached to the steel is the easiest place to get water in to the trailer. No way of telling it is getting in until it is too late.

I am meeting with an engineer next week to discuss having my walls made this way, but have to figure some way to stop the water as we have stream crossings on a regular basis. Normal RV's and living area trailers normally do not see that type of obstacle. They have mentioned a high grade plastic being used by Air Stream. This would eliminate using the wood as a buffer for the top walls connecting to the frame. the next problem is the cost of having the walls built.. I have the tools or access to the tools for bending the steel, and most likely the aluminum, but the welding is another cost for equipment.

Years ago I built a complete fiberglass trailer with steel loops for the frame. These were actually made in Hemet. Jim Moore designed the trailer in 1981, and had the molds made, with the first one rolling in 1982 I think. They were quick and easy to make, but the cost was prohibitive. I am looking at making the front of mine out of fiberglass, like the new trailers have. It would cut down on a lot of cutting and bending. .

I think the ultimate would be aluminum and composite material, but the cost would infringe on sales is my guess.

Steel is readily available, which you can have lazor cut now by the suppliers, and bundled per trailer. My draw back is depending on another business to bend the tubing and the bending of the trim. Eliminating those draw backs by using fiberglass is very interesting.

 

[tassie tiger]

In oz, and I am sure in the US, there is a new product made from recycled plastic that is described as an alternative to marine plywood.

Had a look at some the other day and very impressed. Its called Uniboard.

Heres a link;

http://www.dotmar.com.au/uniboard.html

 

[gonejeeping15]

It all depends on where your at and what your doing. Lets knot forget the Titatic for example, a lot of wood and a lot of metal, but was no match for that big chunk of ice.

 

[86JP-CJ7]

I am looking at aluminum upper frame. Can not afford to build lower frame out of aluminum. Plus I have the fear of it breaking. The problem with upper walled aluminum is that it must be attached to the steel frame with wood. Basically the Trailer industry uses a aluminum frame molded into styrofoam and then laminated luan to the outer and inside wall. The thickness is approximatel 1 inch of aluminum tube and foam, 1/8 luan on each side and 1/8 fiberglass on the outside. The fiberglass and the 1/8 luan give the trailer strength, by lamination, bolts and screws. You can not attach aluminum directly to steel. So the walls have a 1 1/2 inch wood runner on the bottoms and are lagged to the steel frame. This worries me in our use. Wood at the base attached to the steel is the easiest place to get water in to the trailer. No way of telling it is getting in until it is too late.

What would happen if rubber or polyurethane (in either block form or thinner sheets) were used between the steel and aluminum instead of wood? I have been contemplating the theory, but wondering if it has been tested.

 

[bob]

Most likely what Air Stream is looking at. It has to be durable as it is clamped between the two metals. I will try to find out what it is next week. I would really like to use the upper walls and have them manufactured so all I do is bolt and weld them together. It would mean redesigning my trailer, but would make it lighter.

 

[VanIsle_Greg]

I think when done right, either will work and work well. This of course depends on intended purpose, skill of fabricator/mill-worker, materials and of course most importantly, design. I have been following the build of a friend here in town (see link). He is a boat builder by trade and is employing boat building and marine fabrication techniques and materials. I am going to have him build me a lid for my M101 CDN trailer as soon as I can in much the same way.

http://www.expeditionportal.com/forum/threads/65881-My-Woody-expo-trailer.

Very excited!

I love the steel and aluminum trailer builds I have seen, I am also a fan of some of the marine grade wood builds I am seeing too. Times are good in the expo trailer scene these days.