22"x48" Deck Lid Design Questions

[Starkfishes]

I am about to begin the framing on my xPress 1652 and am concerned that I may have a poor design when it comes to the deck lids. The front deck will have two lids. One is 22"x40" and the larger other lid is 22"x48". Does anyone have any experience in how to properly support this size lid?

I am able to do all of the aluminum framing and even the aluminum sheeting for the deck itself; however, my aluminum skills are not good enough to take on the lids. I have tried to outsource them and can't even get he guys to provide me a quote, much less a timeframe to completion. This is leading me to want to simply build them myself. I am considering using 1" plywood (untreated of course). The plywood would be screwed to the hinged side through a stainless steel piano hinge into 1/8" thick aluminum angle. The other three sides would be supported by resting on 1" of exposed 1/8" thick aluminum angle.

Questions:
1. Is this nuts?
2. Would adding 1/8" thick 1/2x1/2 aluminum chanel running parallel to the piano hinge provide enough additional support to prevent flexing and possible warping?
3. Is there a more obvious way to accomplish my goal that I am just missing?

Please help.

 

[Johnny]

that size deck lid will need minimal bracing with 1/2" B/C ext. plywood.
as for the bracing: I would personally suggest a minimum of 1-1/4" x 1/8 or 3/16" square tube or angle
48" is quite a span and must have vertical supports from the lid to the hull.
price is what drives most of us "Common Folk" to use plywood vs aluminum sheet.
(plus - the tools and equipment to work with it).
photos of your concerns will generate more accurate responses from the gallery.


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[user 18775]

I have a 18"x48" tackle storage in my rebuild. I simply split the hatch in half and each one is 18"x24". They are 3/4" plywood, and are light enough to deal with. Mine are supported by offset hinges on the short end, one lifting to the left and the other to the right. I think they are light enough that I won't need assist pistons on them.

 

[onthewater102]

I have a 48" x 20" lid and it just has a piece of aluminum channel made from what appears to be the same gauge sheet metal as the lid run lengthwise and welded to the underside. The channel is 1" x 3" x 1" and is spot welded along the underside. I would think you could do the same without a welder if you put 2 pieces of 1.5" angle back to back and riveted them both to the underside of the lid and to one another. You'll have built a truss out of them & wouldn't need to support them vertically in the middle. You can test it out before you build it by laying a 2x4 under the aluminum sheet 9.5" away from the 90 degree bend applied to one edge of it (assuming you're bending the edges to stiffen them) and gently apply a load to the metal. If it wants to give and flex move the 2x4 closer to the edge until you find where it needs to be to stop any flexing then move it another 1/2" closer for some wiggle room...