Is Wood Strong Enough?

[jcook5003]

Hey Guys-

I am going to be building a teardrop in the near future to tow behind my 1994 Toyota Pickup 4x4.

I was wondering is wood really strong enough to make the frame of the body out of? It seems a lot of you guys do it and it works, but how do they hold up?

I was thinking of building my own trailer frame, and then building a squared of teardrop on a metal 1x1 body frame. I think it would be much stronger than wood, and should be substantially stronger.

Does anyone have an opinion to offer, maybe a link to a similar build?

Thanks,
Josh

[xrover]

With proper screws and strengthening points, wood is certainly strong enough and more importantly easier to work with for most of us. One thing to consider is the weight impact of metal over wood? While you have a strong tow vehicle, you may be hard pressed to try and sell it down the road if it weighs too much for the average 4 cylinder car. From what I see on this board, first time builders seem to relish in their victory, and go on to make a better one.
I remember reading somewhere that some guys were building a wooden car, frame and all out of wood.
There are some links in the forum of guys making the skeleton of the teardrop out of 1" square tube.

[jcook5003]

I suppose if so many people have done it's obviously strong enough......

My toyota makes about 110 horsepower stock when it was brand new, it's now broken in good and has about 150k on it. So I understand lightweight needs.

Thanks Guys,

I just wanted to gather some opinions....now my decision needs to be build a 5x8 version of the simple or weekender, or a more traditional rounded design.

[Trackstriper]

What material will you be using for the body sides/skins? That may be a factor to consider. It sounds like you will be using a conventional steel "chassis" frame and you will add a framework of light steel tubing to frame out the body. I think the guys who have done this have then put aluminum sheet directly on the framework, and that could make a fairly light teardrop or whatever shape. Somewhat similar in construction to a manufactured enclosed cargo trailer that some of us are converting. That could make a lot of sense if you prefer to work with metal.

However, if you wish to add wood skins to the steel framework I would question why not just use wood throughout the bodywork. Fastening wood to steel could be done with adhesives and screws but the the resulting bond might not be as strong as a wood/wood bond with a woodworking glue. The wood and the steel want to expand and contract due to different effects and aren't likely to be in sync with each other. Wood framing won't have this potential problem and by using reasonable craftsmanship will be plenty strong. I haven't hear of anyone's wooden trailer body coming apart (someone correct me if I'm wrong), so how strong do you want it to be? Using a steel frame under wood skins will most likely be heavier...1" square 16 or 18 gauge will be heavier than a piece of 1x2 pine.

It may also come down to what you prefer to work with, wood or metal. You can do well with either, just my opinion.

[Miriam C.]

Build it your way! If metal is what you are comfortable with then use metal. There are a lot of people doing it. If you plan it and are mindful of weight you can come in about the same.

Most important after the pictures is to enjoy the trip.

[kartvines]

I looked at a home built canned ham trailer last month and it frame was made out of wood, it was built in the 40's and it seems to be still holding up, he banded it with metal, if I can locate photos I will send them to you.

[Mark McD]

The type of material has less to do with the structural integrity than does building technique. Just about anything you can think of has been built out of wood at one time or another- boats,cars,airplanes,campers,bridges,buildings etc.
That said, I think most people choose to build with wood because it's easier and most can borrow or buy the few tools necessary for construction- the same cannot usually be said of metal working tools,i.e. welders,grinders,metal chop saws, etc. Not to mention the fact that most people wouldn't want their first attempt at welding to be a trailer that is dragged behind a vehicle at highway speed.

[jcook5003]

thanks, you guys bring up lots of good point.

I already have all the metal working tools, those I dont I have easy access to. Alternativley I already have all the woodworking tools to.

On the topic of skin.....I had thought aluminum skin directly to the metal frame. then 1" styrofoam and something like 1/8 luan on the interior, thoughts?

[Keith]

Hi Josh,

We have built a number of teardrop trailers using one inch square steel for the frame and then covering it with .063 aluminum. They turn out to be very strong nice trailers. We choose to use this method because we are much more adept at metal work than wood work. If we cut something to short we can fix it, but with wood you have to start over. We made the outside shape with a ring roller to roll out the curves and then welded different curves together to make the side. Take a look at my photo link below.

Sumner Patterson used flat strap that he made a side template for and then welded the frame up to it. His build can be found at [url]purplesagetradingpost.com[/url]

I hope this helps, Keith

[Senior Ninja]

Hi,
Gluing two sheets of plywood together with studs and blocks between the wood gives large areas of contact for the glue to hold. It makes for a very strong yet light construction. Using pocket screws and glue to hold the rafters to the sides then gluing both the roof and ceiling to the rafters again provides large areas of glue to bond the wood together. The fact that you also curve the roof and ceiling also contributes to the overall strength of the TD. Screwing and gluing a key to the floor, setting the walls over the key, and fastening them with both glue and staples makes for more large areas for the glue to bond the wood surfaces together. The only thick plywood was the 3/4 that I used for the floor. My tests with yellow carpenter's glue revealed that the wood failed before the glue joint did. That's more than strong enough for my purposes. The very nature of wood makes it a fair insulator thermally and also for sound suppression. There's a warmth to wood's appearance and even feel that cannot be matched by metal, at least to my eye, but that's a subjective judgment. Given my skills and preferences, there really wasn't any choice, but again that's a subjective judgment.
Thanks for listening.
Steve

[asianflava]

I've said it before, I'll say it again. People have done it sucessfully but the question is why bother. There is no weight savings, or cost savings (unless you get your wood for free.) You will still need a steel axle and coupler.

I think this question comes up every so often (do a search for "wood frame" or "frameless designs") because folks don't have experience with steel. Working with steel isn't that different than wood. You can easily cut all the parts for your frame then have somebody weld it up for you.

[Roly Nelson]

Wood is good, just ask Howard Hughes, who built the largest four-engined seaplane ever flown, entirely out of wood. And that was before Tightbond III had been invented.
Roly

[brian_bp]

Wood is good, just ask Howard Hughes, who built the largest four-engined seaplane ever flown, entirely out of wood. And that was before Tightbond III had been invented.
Roly

The Spruce Goose (which is not made of spruce) is impressive, but the material was not chosen because it was better, only because it was available. You can build just about anything out of just about anything (concrete boats, steel airplanes, paper furniture, etc), but there has to be a reason.

If you have a reason for making an trailer structure entirely out of wood (personal challenge, like working with wood, etc) that's great, but I don't think that the reason is going to be weight savings. Similarly, you can steel-frame a teardrop trailer body, and that's right for some people, but wood is the conventional choice because it works well for the purpose for most people.

Various people have built motorcycles of wood, even with wood suspension components, so a trailer could certainly be done with no structures inboard of the axle spindles and ball coupler in metal. I'm thinking wood suspension arms and rubber springs. Not a project for me, but if someone wants to go for it, I would be interested in seeing the result.

[v8dren]

Im building a full size, walk in Teardrop here in the UK, ive built one a heck smaller than my latest project, we've used 1/2" marine ply on outsides and wall dividers, original frame is from a caravan chassis, but my previous TD was all made from 3x2" steam treated wood, if treated properly it'll last years. Im using mainly 1/2" shutter ply for all interior panels and either 1/4" for non- stress area's.

If your building something from wood, with all the correct fittings and joins it'll be as strong as metal and yes there is a weight issue, but personally wood looks better.