Alternatives to plywood?

[jsmoriss]

Hi everyone,

Last summer I took our the rear seats and built a platform from 3/4 plywood. Now I'm thinking of taking this a step further and building two dog kennels and some storage space in the back. Plywood was ok for a single tie-down platform, but now I'm thinking there must be better alternatives -- waterproof and lighter -- to plywood for building 'structures' within our vehicles... Any suggestions?

Thanks,
js.

 

[Layonnn]

sheets of HDPE, waterproof yes, lighter, mmm not so much. But MUCH stronger.

 

[michaels]

MDF board covers in carpet has worked great for me. 3/4" and comes in 8x4' sheets. very strong. very dense.

 

[mhiscox]

If you like the smell of resin in the morning, you can build from NidaCore and cover it with a coating of fiberglass (necessary for strength). The NidaCore is indeed stronger and lighter than ply, but is more expensive and, obviously, more of a hassle. However, NidaCore (and similar composites) is common practice in boatbuilding for above-the-waterline structures, benches, cubbies, etc.

 

[FusoFG]

Thinner plywood.

A 3/4" sheet of plywood weighs about 75 pounds. MDF weighs more.

A 1/4" sheet weighs just 25 pounds and an 1/8" sheet (or door skin) weighs only 12 pounds.

Glued and screwed to a lightweight 1x2" frame (both sides if necessary to make structural panel) will result in construction that is as strong if not stronger at a significant weight savings.

Home made Nida core panels at a fraction of the cost.

Coat with West system Epoxy and its waterproof.

 

[j_nigrelli]

there's a bunch of different grades of plywood, too. for ease of fabrication i think it's got everything else beat. as above, it's a better idea to use minimal thickness and brace where needed.

if you need the strength, aluminum strip can be epoxied (underneath) to the plywood wherever fasteners need to be accomodated. other bracing can be mahogany or PVC depending on the purpose. use through fasteners wherever possible (nuts, bolts, lockwashers, loc-tite, nylock, fender washers). screws don't cut it. break down and use some good quality polyurethane construction adhesive. not the 99 cent stuff, but the $4.50 a tube adhesive. you're probably only going to use 1 or 2 tubes and you cannot be in That much of a hurry to get this project done.


whatever you decide to use, make sure that you seal ALL sides and edges against moisture absorbtion. rattle can spray laquer is a good and quick sealer.

MDF & its evil twin, masonite (and cousins homasote & particleboard) should never (never!) be used where moisture and tension are considerations.

and on top of everything else, these products don't hold fasteners worth a d%@n!!

 

[compactcamping]

For DIYers, plywood is a very suitable material. As j_nigrelli noted there are different grades. I normally use BS1088 Okoume where I want strenght and light weight, a 4x8 1/2" sheet weighs 37 pounds. The trade off is cost. At minimum I would use cabinet grade plywood.

With glue and screw corner block construction you can make some strong and light weigh boxes. For tight wood to wood joints Titebond II or III will create joints that are stronger than the wood. The screws provide some structural strenght, but are really providing clamping pressure while the glue dries. If you want it to be waterproof seal it with penatrating epoxy before topcoating.

 

[jsmoriss]

Thanks to everyone for your excellent suggestions. Sounds like good quality plywood is the way to go -- choosing the thickness appropriate for the job.

FYI - The rear storage is basically a 3-sided box with two aluminum dog kennels on top (approx. 200 lbs for kennels + dogs). I'm also building a sliding bottom for the '3-sided box' that I can pull out for the dogs to jump in/out of the kennels (they'd be too high otherwise).

I could have built the dog kennels lower, with storage on top instead, but then I'd loose access to the 'cubby storage' in the back of the 07+ Wranglers:

js.