Removing Center Bench Seat

Question.

I am thinking of removing the bench seat in the middle of this. Given the supports in the floor does any one see a major problem with this idea? I am going to extend the front deck and put in a floor with storage on the sides.

This is much debated here. Look at the size/length/overall proportion of the ribs of your boat. Look at the size and profile of of the gunnels. Now go to any jon boat manufacturer's site you choose, or all of them. Look at their boats designed to be open. There is a difference. People believe what they want but the difference between those boats designed to be open and those designed to use the center bench as a structural support is clear. And they're made the way they are for a reason. Replace the structure the center seat provides with some deck structure you're probably ok. Just put in a floor and maybe not so ok. The center seat keeps the boat from flexing in the middle.

Good advice.

richg99

Bad idea in my opinion. The bench is a horizontal strut.

As long as you're not going to be running it at 20 mph in rough water, I wouldn't have any qualms about removing a middle seat that is not connected to the floor. The only thing you'd need to do imo is add a stiff wood railing down the sides under the gunnels to add back some stiffness and stability to the side walls. The flooring will also add back rigidity to the frame.

This is just to give you the idea of what many people do.. The seat holds the sidewalls from flexing outward. You need to replace that stability by adding stiffness to the sidewalls:

If you want an open walkway but also storage, why not split the seat and make two separate storage areas? You can keep your structural strength (or at least most of it) by anchoring it to the ribs with aluminum bar. I did mine a few years back. I use the storage for batteries to shift the weight forward. I have never seen any flex in the boat.

chrispbrown27 said:

If you want an open walkway but also storage, why not split the seat and make two separate storage areas? You can keep your structural strength (or at least most of it) by anchoring it to the ribs with aluminum bar. I did mine a few years back. I use the storage for batteries to shift the weight forward. I have never seen any flex in the boat.

Click to expand...

Any pics? My boat is due for the same treatment.

I cut mine out but reinforced it. After I cut mine out I could most definitely feel the loss of structure to the hull. After feeling the difference without the bench, I became a firm believer in reinforcing.



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These are some from when I did it a few years back. Since then I have put a hinge so that the seats tilt inward for access to the batteries which are under the seats. I don't have any pictures of how I braced it but if you would like to know I could tell ya.

That's kind of what I want to do. I'm thinking if I rivet the front and back sides of the bench to the ribs it should be okay to cut out the middle. It has a brace in the middle already which I could brace to the new floor.

I removed the center bench on my 1648m and noticed it twisting a lot before I put the floor in. Now with the floor in it is fine. I'm also extending the deck and adding a gun box but havnt gotten to it yet.

Basically I riveted a piece of aluminum flat bar to a piece of aluminum angle and then riveted that to the seat. The flat bar is then riveted to the ribs on each side of the seat. The floor helps to hold the seat down too.
I will try to remember to take a picture tomorrow to give you a better idea. I just got done building a gun box in mine. My carpentry skills are crap but it turned out pretty good. I just need to carpet it and it is done.

chrispbrown27 said:

These are some from when I did it a few years back. Since then I have put a hinge so that the seats tilt inward for access to the batteries which are under the seats. I don't have any pictures of how I braced it but if you would like to know I could tell ya.

Click to expand...

Thats exactly what I want to do. Can you post more photos.

Ok, I got the best pictures I could. The floor covers up the bulk of it but from the pictures I think I can explain it a little better. I also added some pictures of the gun box I built.

I drew up a little detail on how I did it.

Longer boats will flex more, if it is welded probably no problem, if it is riveted then rivets may work loose, may not. I have a 1448 and I removed the middle bench seat in mine, best thing I ever did. If it flexes it is not or barely noticeable. Save the seat and if it turns out it is not working out then just rivet it back in.
Before;


After:

Surfman, what year/model is your boat? The ribs appear to be pretty evenly spaced out which I would assume would help reduce flex, as the bench might not have been used too much for structural support.


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It's very easy to see what happens to a boat when the sides are not held firmly in position. Take a minute to cut and tape a sheet of paper into a jonboat. Then bend it front to back.. You will immediately notice that the side walls want to spread apart and make it possible for the boat to fold in half.

You need to strengthen the sides of the boat to help prevent it from folding in half. You can do that by adding a board.... or a rod storage locker to each side... anything will work... but you must add stiffness to the side walls to replace the strength that was lost by the seat tying the 2 sides together.

If you want to make a walk through seat that's also an easy way to preserve the structure... just think of it as a U shaped seat... As long as it hold the 2 sides together you're in good shape...

Side storage boxes are good. Also can be used for livewells. This would be a great way to keep those sidewalls from blowing out.
People seem to like to learn boats the hard way.

I did a quick paper boat....



notice what happens to the side walls when the boat is folded... forces similar to what could happen hitting a wake for example:



this is why you need to add back something that will keep the sidewall straight...