Settee top replacement

[Tmacmi]

I had to tear/cut out the top of one of our settee's to get at the black water tank below.

From everything I can see, it was made out of rough faced, cheap grade 3/8" plywood (not marine) and pine cleat mountings.

Is there any compelling reason I should not use standard plywood and poplar cleats?

Thank you

[thomm225]

I just repainted my interior and I believe may settee top is plywood or something similar

[Shrew]

Originally Posted by Tmacmi

Is there any compelling reason I should not use standard plywood and poplar cleats?

Marine grade plywood is made with waterproof glues and do not contain knots, plugs, or vacuoles.

[Tmacmi]

Originally Posted by thomm225

I just repainted my interior and I believe may settee top is plywood or something similar

Nice looking interior!

Originally Posted by Shrew

Marine grade plywood is made with waterproof glues and do not contain knots, plugs, or vacuoles.

Well then I can tell you for sure what is in there is not marine grade plywood

[Cheechako]

Originally Posted by Tmacmi

I had to tear/cut out the top of one of our settee's to get at the black water tank below.

From everything I can see, it was made out of rough faced, cheap grade 3/8" plywood (not marine) and pine cleat mountings.

Is there any compelling reason I should not use standard plywood and poplar cleats?

Thank you

Use exterior ply, it's the same glue as marine ply. It does have voids in the layers in some locations that Marine Ply does not. But you can usually work around them. For one smoother nicer side get Exterior AC, or AB ply. (one side is A grade, the other is B/C grade.)
For cleats, I think Pine is as good as Poplar. Poplar does water stain pretty well. If budget is your issue then Luan (phillipine mahogany) or pine are cheap.

[Shrew]

Originally Posted by Cheechako

Use exterior ply, it's the same glue as marine ply.

I agree. In fact, exterior plywood is also treated with chemicals to protect from rot and bugs. However, it is much heavier than marine ply as a result. The resistance to rot is an appealing trade-off to weight.

[Cheechako]

Originally Posted by Shrew

I agree. In fact, exterior plywood is also treated with chemicals to protect from rot and bugs. However, it is much heavier than marine ply as a result. The resistance to rot is an appealing trade-off to weight.

I think you are talking about the chem treated (green?) ply. Normal exterior ply is just wood and glue.

[Bill O]

Originally Posted by Cheechako

Use exterior ply, it's the same glue as marine ply.

+1 for exterior ply. This is probably a better grade than what you cut out.


Bill O.

[CassidyNZ]

Structural ply in NZ is described in a building journal like this:

“New Zealand manufacturers use Type A (marine grade) adhesives. These are extremely durable and can be expected to provide a quality veneer bond for in excess of 50 years in full exposure and much longer in dry protected environments”

50 years at a fraction of the cost of marine ply works for me. The ply will last three times longer than I have left on this planet

I use this stuff for everything on my boat that gets painted. The description in the article also says:

❚ Visual face grades defining the front (first) and back surface veneers, for example, CD has grade C veneer on the front and D on the back. These grades are:
• A – high appearance grade suitable for clear finishing.
Etc.

Certainly for replacement tops to bunks, there is no justifiable reason to use marine ply unless the vessel is small and weight is a factor (IMHO).