Plywood question

[littlewangzfan]

I checked around here once, special order, dang near $100 a 4x8 sheet. Home depot didn't even know what I was talking about.

Same here at my local HD $98 for a sheet of 3/4" marine grade plywood. You might wanna check this out, Douglas Fir B/C grade for $48. This is what I used for my build. 5 ply only but pretty strong IMO. I have a scrap piece in my pickup bed for about six months now. Totally exposed to the elements without any type of protective coating. Here are the results:

 

[slimmer]

I have thought about this also. Marine grade plywood has no voids in it. Every layer is solid where as regular plywood could have voids and only the outer layers don`t. I have also noticed marine grade is way heavier than standard plywood. Could be because of no voids or the kind of wood it is made from.

 

[KLee79]

Marine grade ply is obviously the best. But i've used, oak ply, douglas fir, birch and blonde ply. They all hold up for most ply builds. If properly coated, they last a very long time with care. Even longer with fiberglass..

 

[boldtogether]

Marine grade just means it is specifically made to be exposed to the extremes of a marine environment. Any quality plywood will work, but consideration as to sealing it should be a major factor in the construction. Exterior rated sheeting is very durable and as long as the thickness and ply count are taken into consideration, great for most any project involving water. Build the tank properly(bracing, sealing, etc.), it will last years and years.

^^Or what they said^^^