Another removing bench seat question.

[UncleTork]

Hey guys,

I have been searching around, reading other posts and looking at all the information i can find. I am looking at removing one of the 4 benches in my 13.5ft boat to put a small floor in. It it a 1955 Alumacraft. I am wondering if i will need to weld in new supports to make up for the missing bench or if this little boat will be fine without it.These do not appear to provide much structural integrity but i thought i would ask you guys. I am thinking that this boat is small enough that it wont hurt it but then again what do i know.

Thank you for your input.

 

[Woodonglass]

Which one??

 

[64osby]

I will assume it is the bench with the arrow pointing at it.

You could pull it. Securely mount a floor. Then mount a box that would tie the side to the floor, giving it structure.

Without the bench or some type of structure I would think your hull would have some unwanted flex. Over time that would lead to the top rails cracking or cracks in the hull near the seat attachments fore and aft of the removed seat.

My .02 from a shadetree engineer.

 

[UncleTork]

Which one??

The one the arrow is pointing to. Second from the stern

 

[TruckDrivingFool]

Woody's been huffin to many fumes today give him a break.

What 64 said and just to picture here's a good example.(image courtesy of Google search not mine)



Some AL angle riveted to the side and some sheet bent in a brake of some sort (homemade or purchased) and you'll have that thing opened up to a dance floor in no time.

 

[UncleTork]

Woody's been huffin to many fumes today give him a break.

What 64 said and just to picture here's a good example.(image courtesy of Google search not mine)



Some AL angle riveted to the side and some sheet bent in a brake of some sort (homemade or purchased) and you'll have that thing opened up to a dance floor in no time.

So i am a little confused. You are saying to rivet AL angle directly to the hull then attach sheet metal to that and the floor? The bench seat is attached to angle brackets from what i can tell (10-12'' or so). Would it make sense just attach sheet metal to the already existing bracket then to floor or does it need to run from the rear bench to the front bench?

 

[64osby]

Sheet metal as in aluminum sheet.

I would run it from seat to seat.

Attaching an angle would probably be the easiest, but if the sheet aluminum were formed correctly it could have the bend formed as part of the piece for both the side and the floor.

 

[TruckDrivingFool]

The problem is to gain the rigidity you are losing from the shape of the bench. You could use some simple gussets made from plate (AL) but they would have to extend far enough out across the floor that they would become an obtrusive trip hazard.

Osby is looking along the same lines (I think) in that you would need to form your sheet into a domed rib like what is already in the floor just longer to go up the sides. This too would need to be riveted to the hull (IMHO) to give the rigidity need and I'm not sure would be enough to match what's lost from the bench.

Both the above would work but where would you put the lost flotation foam and cup holders? :lol:

There you have my ?2 of why I think the torsion boxes idea I showed earlier is your best bet to from a reliable solution.

As a post thought perhaps a sort of U shaped rib of plate run down the sides and under the floor would be a good compromise.

 

[UncleTork]

The problem is to gain the rigidity you are losing from the shape of the bench. You could use some simple gussets made from plate (AL) but they would have to extend far enough out across the floor that they would become an obtrusive trip hazard.

Osby is looking along the same lines (I think) in that you would need to form your sheet into a domed rib like what is already in the floor just longer to go up the sides. This too would need to be riveted to the hull (IMHO) to give the rigidity need and I'm not sure would be enough to match what's lost from the bench.

Both the above would work but where would you put the lost flotation foam and cup holders? :lol:

There you have my ?2 of why I think the torsion boxes idea I showed earlier is your best bet to from a reliable solution.

As a post thought perhaps a sort of U shaped rib of plate run down the sides and under the floor would be a good compromise.

Thank you for clearing things up. You guys have been a big help and i appreciate it. As far as cup holders go they were one of the first things to be incorporated into my plans haha. The lost foam issue is being thrown around by pouring foam under the floor (doubling as floor support).

 

[UncleTork]

I am also assuming that i can weld these supports down rather than rivet correct?

 

[jbcurt00]

Unless the boat is welded construction, I'd rivet not weld any changes

Thinnish aluminum used for hulls can be tricky to weld very well.

 

[Ned L]

Is your thought about installing a sole (the proper name for what you are calling a floor) so that you can actually walk around? I might suggest that on this boat it will be quite like walking around in a canoe. Rather like a balancing act.

 

[UncleTork]

I have decided to remove it. I have found two others that have the same boat on another forum that have modified theirs. The reason for installing a Sole (never knew that, thank you) varies. I like the idea of having an open flat floor plan that allows for easier storage while fishing. Sometimes when hunting we get to a public spot early and we like to take a nap and make breakfast. Also i am adding a new blind and having an open floor plan will allow for the use of folding chairs vs boat seats that attach to the bench.