Building casting deck, need help with support structure

[Hydrilla]

I'm converting this 15' boat into a little bass boat, and am going to build raised casting decks. I am not going to remove the current deck, but plan to leave it as a sub floor. I have 3/4" plywood for the decks, but need some guidance about how to build the support for it without using too much wood (aluminum is not in the budget). Both the front and back decks are close to 4' square, and I'm guessing the height from the subfloor will be about 1' to 1 1/2'. The front deck will go to the console, and the back one will go to about where the seats would be.

Here's a pic, I can provide any other info needed. Thanks in advance for the help!

 

[SuzukiChopper]

Re: Building casting deck, need help with support structure

How about just some 2 x 12"s glassed to the existing deck done the same way stringers are done or floor joists in your house? Don't need near as many (MAYBE 3 across) and then glass the casting deck to the gunwhale after it's screwed to the new structure.

Because it's not an integral structural piece on your boat, you might be able to just get away with using some PL premium and a few screws to hold those pieces to the existing deck.

Two options and I'm sure others will have more.

 

[tashasdaddy]

Re: Building casting deck, need help with support structure

this should give you some good ideas.

http://forums.iboats.com/showthread.php?t=233970

 

[i386]

Re: Building casting deck, need help with support structure

I'm thinking about doing the same. My concern is weight and stability. Adding too much weight to the bow of my boat could be a problem. I'm not sure what "too much" weight is. The casting deck raises the center of gravity as well so it could make the boat "tippy". I think I will probably just temporarily rig a raised up deck for testing before I commit to altering the boat. This would be something like a sheet of plywood and something to brace it. I'll just put the boat in and walk around on this deck a bit (near the dock!). If it's not too tippy I can proceed. I'd like to have a casting deck, but need to be able to walk around and fight that big largemouth w/o falling overboard.

If you can add storage space under your deck that's a big plus.

 

[jtexas]

Re: Building casting deck, need help with support structure

I built a back deck into my 15' fiberglass boat (5' beam). If that's a tri-hull, it won't be the least bit "tippy". But it'll pound you in any kind of rough water.

What I did was, make a floor (about 2 inches off the bottom of the boat). Then a frame out of galvanized pipe and 2 x 4's, the length and width of the floor and nearly the height of the gunnel. Decked it with 1/2" EXT ply finished with fiberglass as described here: http://forums.iboats.com/showthread.php?t=240043

Excuse the crude drawings:

The section over the fuel tanks, I added a "ceiling" of 1/4" ply (reduce the size of the compartment to prevent fume accumulation). Which also provided a small compartment (same depth as the 2x4 width), for tools, fuses, etc. It stays dry.

The starboard side compartment I use for pfds and foul weather gear, water doesn't come in from above, but it's not watertight from below.

the back seat is a good height for a passenger when the pedestal is not used.

 

[i386]

Re: Building casting deck, need help with support structure

^^^ Good stuff. I like the idea of using pipe and flanges. PVC would be even lighter though it can get brittle when it gets cold. With a little ingenuity, one might even create their own light weight fiberglass "pipe" for this purpose. Anyway, I'm not sure what my beam measurement is. I'll check it this evening. I'm thinking it's a lot narrower than 5' but I could me mistaken. I believe the beam width is where the stability comes from. I remember walking around on the fore casting deck of a small Bass Tracker and thinking it was like walking on a dock. They're really wide at the stern. According to their catalog I just looked at, their smallest boat has a 6.75" beam. They also sit pretty low in the water IIRC (not the deep vee models). Yea mine's a tri-hull so it's going to beat me to death going across the lake to get to some of my fishing spots. It can't be any worse than the boat I have now. Should be really good for going up the river though.

 

[Hydrilla]

Re: Building casting deck, need help with support structure

Thanks for the replies guys, this is what I need. jtexas, thanks a lot- I hadn't gotten as far as planning compartments and stuff, those drawings are great- they help a lot. Good weight saving ideas.

I'm going to post some pics on here and maybe some drawings as I put together a plan, and maybe you all can tell me if I'm doing something that makes sense or not.

 

[Hydrilla]

Re: Building casting deck, need help with support structure

Once I am done with the support structure, would the best way to attach the deck to the boat be to glass it? I don't have experience with this but I'd love to learn.