Teardrops n Tiny Travel Trailers

I'm thinking my first project will be a weekender, and I want to bring it in at the lowest cost possible.

I note that there is considerable variance in the cost of plywood. The expensive stuff looks better. Since I'm goign to be coating the thing in epoxy, can I get away with using the cheap stuff?

Zack wrote:I'm thinking my first project will be a weekender, and I want to bring it in at the lowest cost possible.

I note that there is considerable variance in the cost of plywood. The expensive stuff looks better. Since I'm goign to be coating the thing in epoxy, can I get away with using the cheap stuff?

Can you tolerate some warpage? How about around things like doors and hatches, that you wish the would seal, but won't cause you used cheap plywood? Just my thoughts on the subject.... One of my walls is 1/4" out flatness wise at one side of a door frame because of Home Depot AC Plywood....... Shoulda used better stuff, at twice the price it is not much compared to the $3000 or so I have in the TearDrop. Wish I had used plywood with more plys and no voids....

Steve in ST Augustine

Surf some wooden boat building forums and you'll find your answer. NO!!! Since your trailer will be exposed to elements and UV rays, the epoxy won't last unless its replenished and refinished every year or so. Also, after slathering that epoxy all over at 40 or 50 bucks a gallon, and the wood will soak a lot of epoxy up, you'll still nedd to add varnish with uv inhibitors, or paint, over that. Use good grade wood, and you'll end up spending less on the other, more expensive, peripherals.

Zack,

It goes back to that old saying, "You gits what you pays for!" The sting from buying inferior products lasts a long time. By the time you spend the money to repair all that will go wrong, you could have purchased the proper materials in the first place. At least that has been my experience in building things these past 35 years.

On Using Cheap Plywood (vs. Better Quality)

Zack,

You raise a question that I’m trying to answer for myself as well, as I plan my construction of a tiny trailer.

It seems to me that the initial cost of the plywood alone is only one factor to consider, and it may not be the most important one.

Q: Are you intending to build a prototype that will be replaced in the near future, or do you want a long-lived and low-maintenance trailer?

Luan is cheaper than birch, and if varnished, it is serviceable and attractive. (And both are dirt-cheap compared to top-quality, marine-grade plywood.) But the 4’x8’ sheets of luan and the 5’x5’ sheets of Baltic birch sold at Home Depot/Lowe’s/etc. (in thickness ranging roughly 3mm to 19mm) aren’t intended for exterior use, and either will delaminate if not carefully sealed. Sealing requires careful work and some expensive materials.

Now comes the confession: I’ve successfully built knock-about rowboats with Luan without doing more than glassing the seams and varnishing everything, and I would use the material again if the project --a boat or a trailer chassis-- were a throw-away project, i.e., a project that might provide years of service but is really intended to be an initial-low-cost exploration rather than a true-costs-over-its-useful-life project.

One of the huge advantages that comes from using better quality materials initially is product uniformity and ease of workability. You aren’t dealing with trash that has to be tweaked and fussed with, babied and patched in order to create a serviceable product. In other words, “low-cost” often isn’t low-cost if you consider labor and frustration. And with plywoods, you are generally receiving a better quality product for the additional money. (Someone posted his informal hammer tests done on laun vs. birch, and I was shocked to see the differences in impact resistance.)

Part of the reason birch costs more than luan (and hardwood marine-grade plywoods cost multiples of them) is the number of plies used, the soundness of those individual layers, and the type of glue. If those properties are important to the project’s fabrication or use, and plywoods made with luan/doug fir/etc. don’t provide them, then they aren’t truly cheap in dollars or in grief.

Yet another confession: I’m probably going to use luan for my first shell–-rather than dig into my stock of marine-grade plywood-- because I’m assuming that my first shell will be a throw-away experiment (rather than any sort of final statement, much less a piece of furniture on wheels). Using luan means I can build fast and simply fix my mistakes as they occur. (It’s one thing to ruin a $8 sheet of plywood and quite another to mess up one costing $60.)

Lastly, the bulk of the financial costs of fabricating a tiny trailer –-teardrop or non-traditional-- don’t seem to be in the shell itself (unless one is using high-end metals, woods, or construction techniques), but in the amenities added to the shell.

So, your question –-and mine, too-- might be better paraphrased as “What is the appropriate skin for this project? (and let costs follow use).

Charlie

If you use cheap plywood you end up with a cheap trailer. Besides warping the inner plys have a lot of voids and don't hold screws well. You didn't give your location but if your climate is like we have here in So Cal the termites look at the cheap wood like it is chocolate cake and love it. Best to use ACX plywood for sheathing like it was designed for.

Denny

Paulyboy wrote:Surf some wooden boat building forums and you'll find your answer. NO!!! Since your trailer will be exposed to elements and UV rays, the epoxy won't last unless its replenished and refinished every year or so. Also, after slathering that epoxy all over at 40 or 50 bucks a gallon, and the wood will soak a lot of epoxy up, you'll still nedd to add varnish with uv inhibitors, or paint, over that. Use good grade wood, and you'll end up spending less on the other, more expensive, peripherals.

Pauly brings up some good points....but for anyone thinking about epoxy...check with other boat builders or the epoxy manufacturers....Epoxy will not "soak" into a good grade ply....granted...the first coat will penetrate some...you are not going to impregnate the ply with epoxy....epoxy does require a top coat for maximum UV protection...just make sure you use the top coat epoxy with the UV inhibitors and not the construction catalyst when top coating....a varnish top coat if left to the elements may require annual maintenance, just depends how long you leave it out in the sun....automotive clear coat doesn't....and if you need to refinish...unless the epoxy coats have been compromised with a gouge, scrape etc....you will not need to recoat in epoxy....just refinsh the top coats, varnish/ or clear coat...and finally, if you can find good quality epoxy at 50$ a gallon, like West Systems including the catalyst...buy it up....it runs a lot more than that, especially when you have to get the metering pumps....I've got 1 boat with 5 years on it, 1 with 2 on it and no refinishing...granted I don't leave them out in the sun all day, I put a ton of time and effort into them and they are covered....It doesn't matter what you do especially when working with wood exposed to the UV....it'll get to it eventually over time...just take care of it in the meantime....Hope I didn't ruffle any feathers on this....just my experience....and check out the epoxy manufacturers web sites and ask any technical questions...I've gotten good response...check with Destin Dave on this....he refinishes boats for a living......Doug

So what is the "right" kind of ply to use? And how much does it cost?

Zach.....an exterior rated ply....like ACX....how much $ depends on where you are and how thick you want...your best bet is Home Depot or Lowes on that sort of thing....if you want marine grade fir...it can be had from speciality suppliers (typically) but it isn't worth the cost difference...I only used it for the mohogany on my tear...besides I had 2 sheets leftover from the last boat....Doug

Doug is correct on the epoxy/plywood issue. I have built 4 boats using epoxy encapulation and different plywoods. On the first boat I used top grade marine plywood - a waste of epoxy after all. The second boat I used marine ply without expoxy exap. It looks as good as the first. The third I used luan with epoxy encap. It was VERY cheap and looks great. So the 4th boat is luan and epoxy. No warping that I can tell after 3 summers of use. If you want a serviceable project for low cost, go with the luan and epoxy. Now I have to admit that on my tear I am using birch, but that was because I got a great deal on shop grade 4x8 sheets and 5x5 Russian birch from an industrial plywood supplier near where I live. The final project plywood cost for the birch was only about $20 more than luan and $50 less than fir. Just don't spend a fortune on epoxy if you could purchase some aluminum siding instead!

Jeff L.