Teardrop Travel Trailer (added VIDEOS!)

Fair warning!  This is going to be a biggie Instructable.  Fair warning!  I suggest you read the WHOLE THING before you start building.  You may also want to obtain some more detailed plans that include more detailed drawings and dimensions.

Over the past year I've built a 'teardrop travel trailer.'  It's been an adventure for sure.  It's very much been worth it.  I aim to introduce you to the idea of a teardrop trailer and the steps involved in building one.  You WILL need more info to complete a build.  I strongly recommend the forum below. 

I stumbled across this idea because my wife and I were thinking about buying an old airstream trailer to fix up.  Then I stumbled across this web forum: http://www.mikenchell.com/forums/
It turns out that these teardrop (named for their shape) travel trailers were once very common.  Especially after WWII in the states.  Often built of materials at hand and ranged from minimal to elaborate.  Check out this link here: http://www.mikenchell.com/VintagePlans/vintageplans.html.

Well I was hooked.  I considered various designs and what I wanted in a trailer.  You can track down a TON of resources through that forum above, as well as many gracious and helpful and wonderful people.  There are a variety of FREE plans and a few at modest cost.  Note: be wary buying plans on Ebay.  Evidently, there is a fellow who pops up selling the free plans available from the above forum.

I decided to build a 'Cubbie' type trailer, based on plans from a company called Kuffle Creek.  http://www.kuffelcreek.com/  But with LOTS of modifications.  You must understand  that no two trailers are remotely alike!  One reason I picked these Cubbie plans is that there was NO WELDING.  Certainly there are designs where you can weld your own trailer to spec, but mine started out with a bolt-together utility trailer from Harbor Freight.  So without further ado....

P.S. At the time of initial publication (July 2011) I've got the trailer roadworthy, but it's by no means finished.  As I complete further finish work I'd further steps.  Please feel free to ask Qs in the comments and I'll respond as best I can.

Step 1 Buying the utility trailer - piecing it together.

Per the plans I was using I bought a 4x8 utility trailer from Harbor Freight.  It has a weight capacity of 1800 lbs.  Which should be plenty for my trailer.  In fact I took out the smallest leaf spring plates bc of the light weight.   (Step 11)  You can buy essentially identical trailers from other sources, or even fab your own.

I spread out a big piece of cardboard on my garage floor and fitted the thing together.  This particular trailer is designed to fold in half.  The plans call to modify it so it has a solid body.  This involves making an additional spar of wood to put in the middle (I painted it black).

Another mod is to build out the axle ABOVE the leaf springs instead of below it, as the factory plans call.  This allows your tailer to ride lower.  But to do this, you have to cut a notch in the axle brackets.  Hence the angle grinder. 

Comments

[Rob O]

Hey everyone, per requests I've added a few videos at the end. It's the last 4 steps. Please consider voting for this 'ible in the Summer Contest. Thanks!

[dr.knowitall]

lol, yeah actually, I'm a journeyman machinist and that is a trick I learned a long time ago (using motor oil). believe it or not, I've even used vegetable oil as a last resort for aluminum pieces and it works surprisingly well.

[sconner1]

I use any oil i have at hand. Veg, mineral, motor, 3-in-1, air compressor, etc.
Not WD-40 though.
Usually no problems for a few holes.
I suppose if I were working on an industrial scale, I might tell the difference in cutting oils.

[dejure]

For those who want to crank up the life of plywood and such, treat it and all wood surfaces before you apply any other protectant. You can make your own treatment using cheap poly and a hardening oil, like tung oil or boiled linseed oil.

Adding hardening oil to your poly reduces its hardness, but gives it more flex (that's how they crank up the expensive exterior finishes, by making them "long oil" (more oil) finishes. Adding about 25% hardening oil to your poly will reduce its tendency to separate from your wood.

To start treating wood, start by thinning your treatment 50% with mineral spirits, turpentine or naphtha. As long as the wood keeps soaking it in, keep adding it. I'll often leave a bucket by the wood and do other thing throughout the day and add more each time I walk by.

Give the first treatment a few days to harden (the solvent will evaporate off and the poly-oil mix will harden). Then you can drop back to a 25% mix and do the same thing.

Doing this wherever leaks might appear or where the wood would be subjected to water (e.g., around vents, doors and windows, or the underside) can greatly increase the life of your investment. Even if the siding, tar or whatever fails, it will come up against your polymerized wood, which will be protected,

I do this to particle board, such as around sink installations, and it stops it from swelling and falling apart.

[sconner1]

Great tips.

[rowerwet]

I avoided using any fasteners as much as possible on my TD, the box is bolted on with 8 stainless bolts every other joint is only glued with PLPremium construction adhesive, as I build small plywood boats with it and it is water tight and if the joints are made correctly (chine log) it doesn't fail. the only screws I have in my whole build are to hold the walls to the deck and they are special coated deck screws, as the heads face down they will rarely see water.

[rowerwet]

one guy actually has a hole in the bottom of his "cargo" box, by placing the hatch on the ground he can stand up inside his trailer to get dressed etc.

[rowerwet]

I went as light weight on the hatch as I could, I made the ribs and spars the real strength then skinned the hatch with FRP (shower wall liner) held on by channels around the outer edge, I figure the hatch is just a fairing, so no strength is needed, even in snow the curve is enough to just let snow slide off.

[rowerwet]

I made my doors rectangular as square corners are easier to match on my double walled doors and walls (two skins of 1/4" with 1x2 framing and foil faced foam board in between) after a year of using a fwd hinged door I plan on making a gull wing door set up instead, I would like to have a roof to step in and out underneath if it is raining. I plan on making the hinge up top at the roof line.

[rowerwet]

I also used paint for my TD finish, however I did a canvas/paint finish like they used on old wooden boats before epoxies. I bought cheap canvas drop cloth from Home Depot, cut to rough size of each side of the trailer, rolled on the paint thick into the canvas to fully wet it out, then rolled a heavy coat of paint onto the TD, then rolled more paint onto the canvas as I applied it to the trailer. Use porch and floor exterior paint for the final coat and it should last the life of the trailer with a few re-coats as needed. The canvas gives it some nice texture and keeps the paint tough. It also hides a few boo boos that I have in my plywood skin :-)

[rowerwet]

on my TD I used the "live plastic" hinge, much cheaper and fully water proof, Hurricane hinge is great but expensive. (just an option to consider for other builders) you just get a light aluminum strip to put on top of the hinge and screw down through it after laying rtv along the edge. One advantage is that you don't have to figure on heights (offsets), as you may have to with HH.

[fastfloyd]

I am just really puzzled about the hole in the floor. What is it for?

[Rob O]

It's a storage compartment. It's not very deep - essentially just the depth of the trailer frame. But every bit of space is helpful on this thing.

[Mower]

I thought it might be for ice fishing!

[dchall8]

Before I start coming across like a buzzkill, I first want to say that this is an amazing project and you did an amazing job!  Nicely done and nice instructable.  If you wanted to improve upon it you might put a parts list, cost, and sources to buy up front.  But that is beside my other point...

There is a reason why cars (and boats for that matter) are no longer made of wood.  Wood is normally joined together with steel fasteners.  When wood absorbs moisture, the steel fasteners are right there in prolonged, direct contact.  The screws will rust, shrink, and fall out.  Some of the modern deck screws are coated to prevent rusting.  From my experience they work very well.  I have had occasion to disassemble some old projects and the coated screws were actually reusable.  So I would caution people to use excellent hardware when trying to make a vehicle like this out of wood. 

Another issue is that wood shrinks and expands with moisture and temperature.  The joints you thought were tight could loosen without doing anything.  With that in mind I would strongly suggest a full coat of good glue on both sides of every joint.  Leave no room in the bond for moisture to enter the joint.  Wipe the excess after screwing it together. 

Regarding your glue, Tightbond II: it is a glorified Elmer's white glue.  For a project that I wanted to keep, I would use regular Gorilla Glue.  Gorilla Glue is 100% water proof, not just water resistant.  Gorilla Glue also foams and expands to fill wood grain as it sets.  Gorilla Glue joints in wood are stronger than the wood itself.  When I was in college we built a wooden airplane using the glue that is now called Gorilla Glue.  It was the only glue approved for making wooden airplanes.  It is very good stuff.  Gorilla glued joints will not loosen with moisture or temperature. 

Again, very well done project.  Thanks for posting. 

[dejure]

Just a note, or two:

Regarding fastening hardware., it really is a good time to apply that old concept of "I can't afford cheap."

Regarding the filling effect you attributed to Gorilla Glue, while it does fill gaps, the fill offers no structural integrity to your glue joint. To the contrary, glue joints must be tight, just like with Titebond, for the glue to work well. That said, Gorilla glue and similar products by other manufacturers are good glues (one side MUST be moistened, as stated in the directions).

End to end (butt) glue joints don't hold well. That's why you see things like finger joints (like both hands spread wide, then joining them by pushing fingers together to fill the gaps), lap joints, dove tail joints and so forth. Laying boards over the top of each other, then removing half the thickness of both boards, so when they over lap the joint produces the same thickness of a single board, but produces a larger glue surface.

A good glue joint beats screws and nails every day, baring deterioration from moisture or heat, which may not be an issue with most quality glues.

Treating all surfaces of your wood with hardening oil or paint, after gluing, will reduce movement of the wood from changes in humidity.

Since your surfaces are going to be covered, you can use any color paint. As such, you can go to specialty paint stores and buy mismixed oil based paint for a fraction of the retail cost. Generally, five, rather than thirty or so a gallon. One store sells its quality mismxied paint for one dollar a gallon.

Like hardening oils, oil based paints can be diluted (mineral spirits, turpentine, d-lemonine, or Naphtha, whichever is cheapest) and applied in several coats.

[Rob O]

Gee thanks for the half-hearted praise. Read steps 43 & 47.

[dchall8]

Half-hearted? You got two "amazings" and a 2 1/2 unsolicited hints for you to use next time or for people coming along after you to take advantage of.  You have done ALL the heavy lifting on this "amazing" project. 

I would discourage you from skinning it with aluminum.  The aluminum would become a dew trap and guarantee the wood inside would rot.  The epoxy outer covering is probably good.  I'm not sure if wood lasts longer being allowed to breathe or being fully enclosed in plastic.  Years ago I used a polyurethane covering on another wooden project, but eventually it delaminated to allow moisture in.  Hopefully they have advanced the technology with the epoxy. 

Here is a link to the National Woodie Club.  There is a lot to know about wooden vehicle construction.  If someone wants to learn more, the link is a good place to start.  Maybe someone will do an Instructable on building a wooden car from scratch. 

[Rob O]

You are remarkable.

[fzxdf5]

Hope you used Stainless Screws...deck screws will rust out on you...

[Rob O]

WHAT!! Rust!? I've never heard of rust!! What is this 'rust' you speak of!! Perhaps you have revealed one of the ancient mysteries of the universe.

You mean certain metals may deteriorate when exposed to water!! Someone call NASA!! Call the Academy of Sciences!! Call Al Gore and Ralph Nader!! We must spread the word before it is too late!!

I used deck screws. It'll be fine.

[kmckenna2]

Is the sarcasm necessary?

By the way, you appear to have misspelled smooth.

[Rob O]

Yes. It is vitally necessary. We must help warn the world about the global rust crisis. Please do your part.

Thanks grammar nazi for pointing that out. "Smoove" is an internationally recognized variant of "smooth". Ask any rapper. This usage lends a creative and poetic aspect of onomatopoeia to my post. This ultimately makes the world a better place. My other 26,000 viewers didn't seem to mind.

[kmckenna2]

Actually, I pointed out the error because I found the "yooneek" spelling and irregular grammar to be a hindrance in understanding the 'ible. I was under the impression that most Instructable authors sought to create easily understood instructions. I stand humbly corrected.

[coachmachado]

For someone who lives in California (me!), how would you get this registered with the Department of Motor Vehicle?

[Rob O]

Hey coach. I wouldnt have the foggiest idea. Fortunately in KS it is super simple. BUT I can tell you where you can do some research: http://www.mikenchell.com/forums/

Search those forums. I recommend using google advanced search. The search function within the forums is very buggy. Or even just post and ask. There are many many teardrops and other small camper trailers in CA, someone will know. Good luck!

[gmajane]

Hi...I enjoyed your instructable. I have a homemade teardrop that I bought from a friend. How did you get that plate for Kansas? I was told I didn't need one here in Kansas for a trailer that small. I carry the regs at the recommendation of the DMV. Did you make your plate? Thanks!!

[Rob O]

I didn't make it. I bought it at KC Home Trailer Co. They don't have a website.
[phone], 1115 Merriam Ln, Kansas City, KS 66103

[Bubbler]

Well done. I wish I had one of these little campers. Good luck on your travels.

[Mike Causton]

Hi Rob - me again, I'm afraid!

I can't find any mention of the timber size you used for the structural spars on the roof. Was it perhaps 2 x 1?

Thanks, Mike

[Rob O]

I used a variety of sizes. In the front curve mainly 2x1. I used a few 2x2 where I planned to attach some diamond plate AND where the outer skin had a seam.

I also used a couple of 2x3s across the flat of the roof in case I ever wanted to attach roof brackets or carry a load like a canoe or boat.

[Mike Causton]

Thanks Rob!

Hope not to worry you any more now. Best wishes.

[Mike Causton]

Hi Rob - sorry to trouble you again but I'm a little confused following the section where you have affixed the roof outer skin down to the triple thickness spar. Step 36 doesn't explain why and by how much the rear of the side walls is cut back beyond the (same) thickness of the rear hatch. Is this because you need to provide additional space for the aluminium channelling? Pictures in Step 51 show the visual difference very clearly (something like 3/4" more than outer skin on roof) , so am I missing something?

Any help you can give is appreciated. PS: in UK one company only seems to be marketing an 8' x 4' trailer chassis like yours but actually appears more like the one from that other US company you mentioned. Does this pose any problems in converting it to a "fixed" chassis from the folding original as supplied?

Regards

Mike

[Rob O]

I'm not sure how to best answer your Q about the trailer. The trailer I used is here:

http://www.harborfreight.com/1720-lb-capacity-super-duty-48-inch-x-96-inch-utility-trailer-with-12-inch-five-lug-wheels-and-tires-94564.html

It's model number 94564.

I could only speculate how well the other trailer would work. But i can talk a bit about how my trailer was converted. If you look closely at the picture at the link above, it has 6 cross-pieces. (BUT two cross pieces are right next to each other in the middle of the trailer, where it folds. its kind of hard to see.). I modified the trailer so it WONT fold by placing a cross piece nested inside each of the side bars. That leaves only 4 cross pieces, thus the wooden cross piece in the plan. I spray painted it black.

But however you get there, once you have an 8x4 trailer with a suitable weight capacity, that is all that really matters. This trailer has a 1720 pound capacity. I seen it referred to as 1800lb trailer. I think that is just a 'rounding' thing. I've even seen it referred to as a 2000lb trailer. I think that is excessive rounding!

Make sense? Let me know if that leads to any more Qs.

[Rob O]

Hey Mike, no bother, I'm happy to answer any questions. I realized I left out that (not so tiny) detail. Once I had had the tripled-up spar in place AND once I had the profile mocked up for the hatch, I cut away 1/2 inch of material from the side wall. This is to make space for the aluminum channel and rubber molding to seal that opening.

In retrospect I cannot remember if it was 1/2 inch or 3/4 or what. But it was too much as now I have about a 1/2 inch gap to fill with rubber molding. So I'll need to special order it.

Good eye!

[Mike Causton]

Hi - very clear instructions to this point, but a basic question: you here specify 3/4" ply for floor but earlier you stated 1/2". Which is intended please?

MikeC

[Rob O]

Hi Mike,
Sorry for the confusion. I used both dimensions actually. I used 3/4 for the floor decking. But I used 1/2 inch in the walls. Please let me know if you have any more Qs!

[drbill]

The heck with aluminum !
Go for broke with an all Copper Skin coated with a clear laquer to keep the shine !
Yeah Baby !

[bryan3141]

I'm not sure I understand. Why did you want the axle above rather than below the leaf springs?

[DeathMagnet]

With the axle above the leaf springs it lowers the deck of the trailer by 3 - 6 inches (depending on thickness of axle and spring).