marine grade plywwod

[mud2005]

I'm thinking about making my next battery box out of wood and I was reading about plywood and discovered there is marine grade plywood that looks to be just the ticket for making a box.

so my question is... is it worth it? is it worth the extra cost for the marine grade wood? I've been meesing around with some 1/2" maple plywood from the local hardware store and some of the layers are not glued very well and when you cut it up you get some funky edges.

has anyone here used this marine grade stuff and how do you like it? and if you like it, whats the best to use as far as type, maple, oak, pine....

thanks in advance for your responses.

 

[Alan B]

I'm thinking about making my next battery box out of wood and I was reading about plywood and discovered there is marine grade plywood that looks to be just the ticket for making a box.

so my question is... is it worth it? is it worth the extra cost for the marine grade wood? I've been meesing around with some 1/2" maple plywood from the local hardware store and some of the layers are not glued very well and when you cut it up you get some funky edges.

has anyone here used this marine grade stuff and how do you like it? and if you like it, whats the best to use as far as type, maple, oak, pine....

thanks in advance for your responses.

I have been searching for box material as well. Marine Plywood was recommended to me by a friend who works with wood and metal. It is much higher quality and thinner ply than regular plywood. It is also a bit heavier. I have not tried it yet but am planning to.

Another material that I've looked at is Marine StarBoard. It is a plastic material used in place of wood in some marine applications. StarBoard has been used by a few folks here on ES for battery boxes.

 

[Hillhater]

Marine ply is far better than other grades. Hardwood faced ( Teak or Mahogany ideally) will have a much better/smoother surface than softwood ply. You wont get any cavities or poor laminations either.
Obviously, it goes without saying that its waterproof.
If its simply for a protective box, with little structural strength requirement, you could consider some of the HD fibre board. Its very homogeneous, smooth, and easy to work with ( so highly favoured by cabinet makers)...but it will need waterproofing.

 

[Rassy]

When I was looking for something to make a pusher trailer a couple of years ago, I came accross a plywood product called "Matrixx Engineered Underlayment". 5 plys, 1/4" thick, and not anything like normal wimpy 1/4" plywood. A bit spendy at 30 + dollars per 4X8 sheet.

Not marine grade, but very solid, no voids, smooth faced. I used it and was very happy with the results. Light sanding, primed, and brush painted with enamel.

 

[mud2005]

You wont get any cavities or poor laminations either.

cool, that is what I was hoping to hear. I'm also going to look into those different types like starboard and such. thanks all

forgot to ask, what about buying online, any good links?

 

[John in CR]

You're not building a boat, so marine ply is unnecessary. The material you use should be determined in large part by exactly what you want in terms of a protective container for your batteries and how accessible you want them to be.

 

[gogo]

^What John said. I had a job making Formica laminated countertops with HDF/MDF underboard and can tell you that as long as you use a good sealant, you can use any kind of wood. When the edges of plywood sink holes got wet it didn't swell it just rotted. HDF and MDF will swell substantially when wet, but as long as you seal properly and avoid water pooling they are ok.

 

[Alan B]

It is pretty hard to seal wood completely when it is going to be outdoors in the rain occasionally. It would be nice if the glue in the wood was inherently waterproof. It would also be nice if there were no voids, etc in the material. In my box I need to use fairly thin material as there is little enough room already. So it needs to have some strength even though thin. I'm planning to use 1/4" material. The weight will be mostly carried by the bike tubes so the wood is mostly a cover.

So it seems to me that a thin ply high quality waterproof and blemish free plywood would be good. This sounds like marine plywood??

Aluminum would be good too but it is harder to work with and I'd prefer to have something non-conductive. Plastic would be nice but again harder to work with.

I have worked with MDF and it is not very strong. It swells like crazy when wet and I'm sure some water would get past the paint at some point. It doesn't take screws well. It would be good for prototyping.

The only two downsides to marine plywood that I've heard are weight and cost. These may not be a big problem as we don't need a lot of material. Are there other downsides?

 

[JEB]

I have been using for years what is called "Baltic Birch", the almost 1/2" is 9 plies, very strong, no voids, glues well, must seal, it comes in a few thicknesses.

When I worked for GM back in the 50's we used a plywood like this only 3/4~" thick, to make temporary sheet metal dies. We called "cookie cutter".

 

[REdiculous]

I'd probably use polycarbonate. IMO, it's not any harder to work with - trying to glue and screw 1/4" material is a PITA (be it plywood, MDF or whatever) so I'd probably use brackets and bolts to hold it together anyway.

 

[TylerDurden]

Also consider PVC sign panel. 'Sintra" and other trade-name products.

 

[Harold in CR]

No one uses Masonite anymore ?? With todays epoxy, just add corners of light gauge Aluminum angle and epoxy.

 

[bobc]

may be worth considering fireproof ply?

 

[nicobie]

JEB got it right. Use Baltic Birch ply. It comes in 5x5 sheets and different thickness. If you can't find that just use any ACX ply. A grade one side,C grade the other and X for exterior = waterproof. A good yard will have it in all thicknesses.

For a nice look, you might use alum. skinned ply.

 

[kriskros]

YES, use 6mm baltic birch and fibreglass the corner joints with 2" wide glass strips in stead of using screws... very strong an waterproof

 

[marty]

Every time I see a band playing music, I look at the equipment cases and think they would make nice custom battery boxes. Not sure what they are called? but ATA is Air Transportation Association. I searched for ATA case

 

[John in CR]

Guys, you're losing sight of the fact that Mud really just wants a shield or cover for his batteries. The bike frame will provide the strength. 3mm or 1/8" is all he needs, and marine grade plywood is really unnecessary, as is 1/4" or thicker baltic birch. The cost, weight, and extra width of something more than cheap thin ply isn't needed. I like plywood for protecting batteries, because it's cheap, easy to work, easy to finish, and it's non-conductive. Protect it with the finish and regular ply will be fine. It's not like building a boat or other outdoor structure that you expect to completely expose to the elements outside continuously for years. If that's the intended use of this bike, which would be a great goal (just leave outside riding or parked in any weather condition), then no type of wood is the correct choice. For that kind of bike you need aluminum, plastic, fiberglass, etc.

For the kind of box/cover Mud wants, I'd use a fairly soft but durable solid wood at the perimeter to make nicely rounded corners without exposing any plywood end-grain. Then use a very thin plywood for the sides with at least one good looking surface for the exterior, one permanently attached and sealed, and the other attached with screws and some kind of gasket for relatively easy access. Void in the ply don't matter for this application unlike speaker building where loose material in a void can buzz or in a marine or true fully outdoor application where the void results in a weak spot .

 

[dingoEsride]

Ive used marine grade 9mm ply for my box but thats because it was an off cut laying around from a external panel job I did, it is great in that it is strong, without voids, easy to work with all of which was already mentioned and also very expensive, unless you can buy a small portion of a full sheet at a reasonable price I might be looking at something more moisture resilient after all it is just wood with waterproof glue, having said that with a good sealer, someone mentioned resin, it should outlast the bike and maybe even yourself