Lauan plywood for mods ? Aerohead please advise

[Cd]

If coated with a waterproof sealant, could Lauan plywood sheeting be used for mods on a car ?
A 4 foot by 8 foot sheet weighs in at just a few pounds, is fairly flexible, and can be cut with a box cutter - and costs less than $15.

( The main issue i would think of would be warping. )

I'm trying to think of the most eco-friendly way to skin a frame.

Aluminum can be recycled yes, but there is still the pollution from mining and manufacture of the product.

Fiberglass is a no-no, and I haven't been able to find any aluminum sheeting online that is already recycled. Besides, it's too expensive !

I used to have access to loads of free used Coroplast, but that is no more. :-(

Getting back to the Lauan sheeting, I found out more about where this stuff used to originate from. Lauan plywood is from the rainforest of the Philippines, and until the Eco groups got tough with places like Lowes' and Home Depot, most of this stuff was coming from these areas.

Not Eco-Friendly and just the opposite of what we need !

Now that they have been sued, Lowes is now carrying Lauan sheeting that " Contains no tropical hardwoods " and is " Plantation & Sustainable Wood Source " from Patriot Timber.

What i find truly ironic is that it originates from China despite the " Patriot " name and the prominent American patriot logo.

So Aerohead, please feel free to advise me on whether this stuff can be used for something that has a lot of complex curves. I know you did your bumper in wood and got fantastic results, and i was wondering if this stuff could be used on something such as a boat-tail if installed in sections. How can you be sure that it does not warp ?

My car is dead now, so no boat-tail for me, but I'm just daydreaming here.

BTW, for the artists out there, this stuff is excellent to paint onto. A 4' x 8' canvas would cost hundreds unless you made it yourself, so you can save tons of money over the long run. I have a 4' x 8' sheet of the stuff just waiting to be painted on, and at $ 15 a sheet, there isn't that pressure to create a masterpiece because the canvas is so expensive !

[NeilBlanchard]

Here's the best use of Luan plywood that I know of:

[Cd]

Awesome !

[JRMichler]

My topper is made of lauan plywood. Lightweight, smooth surface, cheap, easy to work with. I like the stuff.

It has been on the truck since December, 2010. I sealed it with epoxy (just resin, no cloth), and coated with paint. As long as all surfaces and edges are sealed, it will not warp.

[Occasionally6]

I love that velo.

Re. ply: Wood is a much under utilised material in 'one off' car projects but there are some examples. The guy that built that velo also built a car using wood and based around Citroen 2CV mechanical parts. It's a work of art.

There are also the Splinter, Marcos and Costin F2.

Boats and canoes have been built using bent ply or layered veneer, known as cold molded construction - ply wood in situ. That velo borrows another construction technique from canoe making; stitch and tape. There's a lot of info on how to build using those techniques around.

One really good book (it's around as a downloadable pdf) is published by West Epoxy on cold molded boat construction. That covers a lot of useful techniques.

[sid]

My experience with using thin plywood of any type that is exposed to the elements without a layer or two of fiberglass over it is that it will eventually crack. Once it cracks it is no longer as aerodynamic and it starts to absorb water and rots. It doesn't matter if the coating is epoxy, polyurethane, or whatever; without any reinforcing fibers across the top wood grain it will crack.

[JRMichler]

Way back when, I built a sailing dinghy out of 1/4" fir plywood. Standard lumber yard plywood, not marine grade. Painted it inside and out with a good coat of primer, followed by a topcoat of enamel. All surfaces were fully coated, no gaps or thin spots.

That boat was stored outside upside down on blocks when not in use. I sold it after nine years. The plywood was perfect - no weather checking. Some of the bottom paint was wearing thin and starting to expose the primer.

I believe that plywood checking is caused by wet/dry cycling. If all surfaces, including hidden surfaces, are sealed, then the wood maintains a constant moisture content. Constant moisture equals zero expansion/contraction, so no checking.

[moorecomp]

Look for Meranti marine plywood. It is available in 3mm thickness. Waterproof. Also look up "Radius chine" construction. It shows how to use strips of plywood to go around corners.

[skyking]

you can also use bending plywood. Normal ply has the grain of each sheet rotated 90 degrees for strength. This makes bending a bit difficult.
Bending ply is designed to bend. The veneers are all laid with the grain in the same direction. You can get either 4x8, or 8x4 depending on which way you wish to bend it.
Columbia Forest Products : Radius Bending Plywood

[aerohead]

The De Havilland Mosquito "wooden wonder"
of WW-II fame nailed the compound curve issue.But not with plywood.
They had concrete female half-molds of the fuselage in which plies of sheet wood and adhesive were interlaced,then a tailored rubber bladder was inflated within the mold,ramming the plies against the tooling until the glue went off.
That would be the gold standard for fabricating.
I have used Lauan 1/8-inch door skin,sealed with cheapo polyester resin for single-curve panels.As long as you can keep the moisture out you're okay.
As the other members have mentioned,the marine plywood is great as well as the bendable plywood.
Papier Mache or strips of brown paper bag with starrch can also be used for compound curves.Lighter,or as light as carbon fiber epoxy when sealed with resin.