Removing Bench seats in boat replacing with floor

[ac777]

Whats the best way to do this and keep the structural stability in a little aluminum boat that the bench seats provide? Any tips or tricks? Whats the best way to attach the new floor to the hull? Links to old threads might help as well, I didnt find any with what i was looking for.

[Musky hunter 82]

I removed the middle and the rear bench seats in my 14' Lund. What I did with the floor is run 2 treated 2x4's from the back of the boat all the way to the front seat (not the really little one in the front the next one back). I then fastened the 2x4's to the transom supports and through the support for the front seat. Then i attached my compartments to the floor and through the sides of the boat. The sides of the boat don't move at all when I grab it to climb in the boat.

[ac777]

Musky, That looks nice. What kind of plywood did you use?

[KidMoe]

That looks awesome! I bet it fishes great too! You've given me the inspiration i need to rip the middle bench out of 16 footer. I also like the cover you have on the transom to cover the gaps between the gunwales and the motor. Couple questions though... Did you fasten the pedestals to the 2x4 to help anchor them?

Also did you find that the boat rides lower in the water now that you added all extra wood?

How well does the boat drain if it rains or catches a big wave?

[jwmiller33]

Musky, That looks nice. What kind of plywood did you use?

I wouldn't recommend using anything but marine grade plywood in a boat restoration like this. If you use regular plywood, you will regret it after a year or two

[Musky hunter 82]

I used 1/2" Treated Plywood. I ended up needing 3 4'x8' sheets. The reason I went with 1/2" instead of 3/4" was the weight, and cost. I figured I could add more Treated 2x4's to the floor for added support and not gain as much weight. I did attach the pedistal seat to the 2x4's for added support. I started with the floor and then the compartments, I got everything to fit just the way I wanted it to. Then I marked out where I wanted the seats and ran a couple of extra 2x4's in order to attach them to it. If any one is intrested I do still have the blue prints taht I wnet off of, I did have to tweak them a little though. One thing that I would recommend is that if you want the sides of the compartments to fit tightly to the sides of the boat make a template out of a piece of plywood aand get the angle right, I used the same piece for all of my compartments. It'll save a ton of headaches.

[soft]

Musky Hunter,

I have a 14' Alumincraft and just want to do the same thing as your boat, I am interested in your floor plan, please email me [email protected].

Thanks.

Soft.

[Castinski]

I took out the middle bench of my 14 ft alumacraft. I left the outsides of the bench attached to the boat and then ran aluminum angle accross for supports. I ran the aluminum angle across the bottom of where the old bench was and then perpendicular up to the remaining benches. Then, I laid my plywood on top of the aluminum angle to create a sturdy floor that doesn't shift or bow at all. Using the aluminum angle also allowed me to cut down on a lot of weight vs using 2x4's.

[ib_jigged]

I have read somewhere that the chemicals in treated lumber (green treat) will cause corrosion of aluminum. Not sure if that is correct, but not worth the risk of placing treated against aluminum in the bottom of a boat.

[jwmiller33]

if you wrap the plywood in carpet so the wood doesn't touch any of the aluminum, you should be good. I have also heard that there are certain kinds of treated plywood these days that aren't corrosive with aluminum. I'm sure the guys at the lumber yard could tell ya what kind of wood to buy if you tell them your using it with aluminum.

[TooTallTom]

IS there any chance of the carpet wicking the chemicals out of the wood when everything's wet? It would be a far safer route to just go with marine or regular plywood that's been varnished or coated some other way.

It would not be much fun to find out that the plywood has eaten your boat. Especially if you find out when the boat's being pounded by rough water with you in it...

[jwmiller33]

I agree, if you look at my post earlier in the thread, I said marine plywood is the way to go. I was just giving options.

[crappiegetter]

There is another forum HSOforum I know of that is only dedicated to boat modifications involving aluminum boats. A lot of very good info and pictures of their projects. I have been looking into ideas for my project and thats were I'm getting most of my info and ideas. [Note from admin: Your post has been edited. Please read forum policy before posting again. Thank you.]

[Musky hunter 82]

Does anyone know for sure about the Treated plywood thing?? I didn't think about that and really don't want that to happen. My plywood is wrapped with the carpet, there is a little gap between the wood and the boat also I'd say about a 1/16"-1/8" gap. So what is the difference between the two kinds? I also thought they were the same thing.

[jwmiller33]

It all depends on what kind of treated plywood you used. I know a few years ago, it was all made with a chemical that is corrosive with aluminum on contact. I don't know for a fact, but I read somewhere (maybe on this forum) that certain types of treated wood nowadays are okay to use with aluminum because there is a different chemical used. Surface Tension would be a guy that would know. Sorry I can't answer your question. I hope you don't have any issues. You could always go and ask the people at whatever lumberyard you got it from

[Surface Tension]

Musky hunter 82, good job incorporating storage to support he hull.

Adding storage, livewell, casting decks, and rod lockers are a natural for that.

ACQ treated plywood.

On your boat project use stainless steel fasteners as they won't corrode with the treated or the aluminum.

Don't let the treated plywood come in direct contact with aluminum.

Since the plywood is wrapped in carpet your not in direct contact.

There isn't any documentation regarding leeching effects.

If that is a concern use a gasket like self stick window flashing or ice & water shield at those locations.

Areas that rot first are areas that are covered like under seat pedestals.

Those areas get wet and take a long time to dry out.

Pedestals will need some sort of backer to stiffen the floor and give fasteners more to bite to.

One disadvantage with treated plywood is its tendency to warp.

This shouldn't be a problem if you have the proper amount of horizontal supports and anchors along the hull.

That leads into another topic about using wood for stringers.

There is going to be a huge amount of humidity under the floor.

There is also a good chance that the stringers are going come in contact with water.

The best option there is to break the stringers out of aluminum leaving flanges to rivet or screw to the ribs..

They won't rot and they don't add much weight.

I realize that few are going to have access to a break to do that.

You can use treated there with a gasket at contact points and use L brackets to tie the stringers to the ribs.

You are adding weight though.

[jwmiller33]

see I told you Surface Tension would know! that guy knows everything

[Musky hunter 82]

So I found out about Treated Plywood vs. Aluminum. I guess that 4-5 years ago they switched the chemicals that they use to treat the plywood, and in a nutshell it contains more salt then before, so if you have it in direct contact with bare aluminum it can cause corrosion. The difference in Marine grade and Treated is the chemicals that they use, Marine grade was made for wet conditions, and Treated for ground contact. I hope this makes sense, so I should be ok since the treated plywood isn't in direct contact with bare aluminum (there's carpet and paint inbetween).

[TooTallTom]

Thanks for the tips Surface Tension and Musky hunter 82.

I keep getting amazed by what I used to know and no longer do. This is especially true for stuff like fishing or hunting regs. I used to read those suckers every year as a kid (like they were comic books or something). As I got older, I figured that I had it covered based on my extensive knowledge and experience. Now, I'm starting to think I'm going to have to go back to doing what I did as a kid.