Treated plywood deck and alum boats-Don't do it!

[HURRICANEBOB]

Marine ply, 1088 and 6566 grade, are not chemically treated and will not cause corrosion in an Alu. hull. They are simply a high grade hardwood ply, with no voids, more laminations per sheet and a glue that is water rated.

What is Marine-grade plywood?
Marine-grade plywood is a specially designed panel made entirely of Douglas-fir or Western Larch. The grade of all plies of veneer is B or better, which means it may have knots, but no knotholes. The panels are sanded on both faces, and are also available with Medium Density Overlay (MDO) or High Density Overlay (HDO) faces. The maximum core-gap size permitted is 1/8 inch. Its exposure durability rating is EXTERIOR and the glue used is a fully waterproof structural adhesive. It is considered a “premium” panel grade for use in situations where these characteristics are required, i.e., for boat hulls and other marine applications where bending is involved.

Costs:
Lowe's: 4ft x 8ft x 1/2in Fir CDX Treated Plywood $24.95
www.almquistlumber.com: 12MM HYDROTEK MARINE MERANTI 9 PLY $71.55 or 1/2" 4X8 AB MARINE PLYWOOD $64.45

Or, what about composite decking?
Pontoon Stuff: 4'x8'x3/4" sheets Coosa Composite Pontoon Decking US $225.00

[coombro]

Marine ply, 1088 and 6566 grade, are not chemically treated and will not cause corrosion in an Alu. hull. They are simply a high grade hardwood ply, with no voids, more laminations per sheet and a glue that is water rated.

What is Marine-grade plywood?
Marine-grade plywood is a specially designed panel made entirely of Douglas-fir or Western Larch. The grade of all plies of veneer is B or better, which means it may have knots, but no knotholes. The panels are sanded on both faces, and are also available with Medium Density Overlay (MDO) or High Density Overlay (HDO) faces. The maximum core-gap size permitted is 1/8 inch. Its exposure durability rating is EXTERIOR and the glue used is a fully waterproof structural adhesive. It is considered a “premium” panel grade for use in situations where these characteristics are required, i.e., for boat hulls and other marine applications where bending is involved.

Costs:
Lowe's: 4ft x 8ft x 1/2in Fir CDX Treated Plywood $24.95
www.almquistlumber.com: 12MM HYDROTEK MARINE MERANTI 9 PLY $71.55 or 1/2" 4X8 AB MARINE PLYWOOD $64.45

Or, what about composite decking?
Pontoon Stuff: 4'x8'x3/4" sheets Coosa Composite Pontoon Decking US $225.00

I started to go that route as weight was a factor for me and I was told that once you cut into it you had to treat the edges? Thats why I went with the fiberglass route.