Making bench seats for a 14' open aluminum boat

[JT2]

Hi all,

The current seats in this old Mirrocraft 14' deep V aluminum boat are pretty rusted out. They consist of three 3" pieces of plywood spaced to form a 12" wide bench seat, covered with an aluminum shell for the top of the seat. The sides look like sheet metal and are rusted out.

I would like to replace this with wooden seat top so that it looks a little nicer than plain aluminum or plastic. What I am thinking of doing is getting 1"x12" (3/4 x 11 1/4) Poplar or Red Oak boards for the seat top. I will use extruded polystyrene foam blocks for the floatation, with the sides being 1/4" thick Azek trim board, shaped into a rhombus shape to match the old seats. I will use two galvanized rods with large washers to clamp the Azek trim boards together to hold the foam blocks between them.

The thing I am unsure of is whether I will need additional support under the wood bench seat to stiffen it up. Perhaps some 1"x2" strips of wood secured perpendicular to the bench seat board?

Suggestions, comments appreciated.

 

[jigngrub]

Re: Making bench seats for a 14' open aluminum boat

What will hold the seats and the floatation in the boat if it takes on water?

I suggest framing your benches out of 1/16" thick aluminum angle, 1"x1" or 1-1/2"x1-1/2". Use blind (pop) rivets for fasteners, you can use closed end blind rivets to fasten the perimeter angles to the boat.



This will be a very light and sturdy build that will never rot.

You can attach your Azek boards to the framing with rivets and your seat board on top with either stainless steel sheet metal screws or more rivets. I personally would use 3/8" exterior sheathing (plywood) for the sides and Douglas fir for the seat board finished with a marine grade varnish or an exterior grade urethane for a nice wood on metal look.

Aluminum angle can be bought cheap by the pound at scrap yards and recycle centers.

 

[Bob_VT]

Re: Making bench seats for a 14' open aluminum boat

Forget the red oak. It is not good for boats and white oak is the preferred wood. Red rot's out quickly.