Replacing wooden seats in an aluminum fishing boat

Sorry that this isn't a more technical question.

I am the new owner of a 1983 12' Klamath aluminum fishing boat. It appears to have the original 3/8" plywood bench covers, which are trashed. I'd like to replace these with either new marine plywood or aluminum.

Other data point: This boat will only see fresh water.

Questions:

1) Which is the better choice?

2) If plywood, is there a preferred sealer?

3) If aluminum, which gage?

Thanks,

Jeff

 

Either material will work. aluminum is a lot less work, plywood is usually more comfortable.
I don't know much about aluminum, but if using plywood, it's best to seal it with epoxy (secveral coats, until completely filled on the surface).
If the plywood is fir, I would add some light fiberglass cloth to the top to eliminate the possability of the grain checking. Other plywood species should be fine with just epoxy alone, but make sure to round off all edges before epoxying. Then paint for best protection.
You can also get by more cheaply only painting (3 coats porch and deck enamel works well), but if you can, at least seal the ply edges and mounting surfaces with epoxy.

 

Aluminum will need a some "brake" work and likely some supports under it, to keep it stiff enough to support a person that's standing or jumping on it. It wouldn't be difficult to arrange or build, but welding should be done by a skilled aluminum welder.

Plywood or solid wood is an option and as Alan pointed out is best sealed with epoxy, then painted (to protect the epoxy).

On the other hand if you just want a functional seat and have some brackets in place for the seat to land on, you could use some plastic decking material. They sell it at Lowe's/Depot as a replacement for regular pressure treated decking. It's usually about 6" wide. Just buy one 8' piece and cut it to length. Of course you'll need a few of these laid edge to edge, but you will not have to paint them and they will not rot. Just screw them down to the brackets or seat box.

 

Thanks very much, guys -- these are great suggestions. I'm leaning towards aluminum (I have access to a brake and a friend that can TIG weld), but I'll look into the decking material, too. I intend to mount some padded, folding seats on the benches, they material I choose doesn't need to provide all that much comfort.

 

Just bear in mind, while plastic decking is very weather resistant, it has no stiffness per se; suspend it across a span and it will seem strong enough at first. Within a year in the sun, it will develop a sag. Real wood will not do this in any noticable way.
Plastic decking is also very heavy. Aluminum may be the best solution for carefree maintainence. Varnished wood is pretty and comfortable, but requires a little upkeep. If you do use wood, three fir boards (made from decking dimensioned at 3/4" x 3 1/2") cleated together make an 11" seat, perfect for sitting width and nice looking with a few coats of varnish.

 

If you do decide wood, make sure it is "insulated" or protected from the ally properly. If the wood over time soaks up the surrounding water, you'll get poultice corrosion under the seat...not a problem, since it is just a seat..but worth noting!