Removed seat bracing; who's the engineer here?

I searched the board for a week and really didn't find any thing on bracing after you have removed your interior seats. Bracing with aluminum, wood...... Remember the object is to keep as much floor open as possible. Here is my pictures from yesterday. The cracks are in the second set. https://www.tinboats.net/forum/viewtopic.php?f=13&t=9001

How would you brace it back up? Fab seats again and use the deck as the top?

How about keeping the boat open and no seats? Brace off the side walls how?

No engineers? How about some backyard fabricators?

Wildman said:

No engineers? How about some backyard fabricators?

Click to expand...

Remember...none of the above.
If I was worried about hull flex with an open floor plan,I'd either beef up the existing ribs or add more ribs.
I see you angled in to decrease your floor width,thats going to help.
Maybe some angle aluminum welded/riveted to the existing ones will toughing them up.I'm not to sure how strong that weld stuff you used is?
More ribs would diffenitly make the floor stronger.
I'm sure others will chime in with there 2 cents,give em some more time.

You have to think about where those cracks are. They are in the center. That means that your primary bending moment is happening right down the center.

Unless you do something to strengthen that area like making stiffer floor ribs, carrying your diagonal side ribs all the way past center or putting the seat back in... it will continue to flex there.

If you put a stiff floor in and then fastened that to your ribs from side to side, that should stiffen the bottom considerably also.

Yes, the cracks are in the 2, 3, 4 rib from the front of the boat and are in the center of the boat. I am planing on, where the braced angles are now, to put in another "seat" meaning that I am going to put in a face on each side of my framed "wall" and then the top of the "seat" will be my deck. I plan on doing this; what do you think?

The two dark black boxes are where the "seats" will be put back in for bracing.

The red tick marks show where the stress cracks were in the ribs. I think those are fixed. My question is, with the new "seats" put in, will this brace the boat for stress now?

I would put a brace in the middle of the seat going to the floor on both sides of the seat if your not already going to do that.

Are you talking about the upright supports I have drawn in on my bottom bracing diagram?

Were the ribs broken before you put the first interior in the boat or did that happen afterwards?

Is the console in the original location or has it been moved? Where were the original seats?

Your proposed "seats" will stiffen it up some but it is still going to be weak in the center where the cracks are if you go with your sketch. A stiff floor around the console that is tied into the side bracing and bottom ribs will stiffen that area in the hull. It has to be tied together, though. It can't just be cut to fit and held in place by a minimal number of fasteners in the corners.

Yes the ribs were broke before I did the first modification to it. I did not brace anywhere just "patched" the ribs thinking they would hold. They didn't

The console is moving to center from side. Reason is that I am getting the weight to center to help the flex all I can.

I plan on tying the sole down to the 1 1/2 square tube runners that will go from back to front and be welded down to the ribs. Then my "seat" vertical panels will be tied into the framing of the rib supports, the side walls with corner braces, sole with corner braces and then tied into the deck and then of course I am going to glass all the angles (wood/wood) together with fiberglass mat.

Is there a product resin that will bond aluminum and wood? I was thinking of trying that 3M 5200

Just for holding in place or as a structural bond?

5200 is basically just a marine sealant somewhat like caulk.

No, I need it to be structurally adhesive.

Ok, my friend and partner in crime came over tonight. Said my idea of bracing would suffice so I am now going to flip her over and gluvit then start working on the bracing, sole, sides, decking, sanding, fiberglassing, sanding, sweating, drinking......

Click my boat in my sig. I removed the bench seats in my boat and put in a flat deck. I am not an engineer, however I ain't worried about my boat failing structurelly. The floor, front deck, and rear floatation compartment will prevent the boat from folding in half. The fishing pole holers provide plenty of stability on the starboard side. Take a look for some ideas.

Good ideas on hardware. I like that pumping with the livewell. My paranoia is from a build to a bust finding that I didn't brace enough the last build and had ribs collapse again. I guess I am just paranoid and gun shy