aluminum bench seats popping?!?!

[StephenSharpe]

I decked my jon and didnt notice before but when you sit or stand on the benches they pop and i k ow its really loud to the fish bc its really loud to me. What can i do to keep them from flexing and popping?! Any ideas?

 

[thudpucker]

Your gonna have to get right down to the Seat/Hull junction.
If it's Loose Rivets, you can tighten them or replace them.

Moisture in the boat may indicate a loose rivet below the water line. :roll:

 

[Scott1298]

If it's not rivets, maybe a shot of expanding foam through a hole in the area of concern?

 

[StephenSharpe]

No loose rivets everything is very solid except for the top of the seat where you would normally sit down. Its like its stretched so it pops up and down. Kind of like the top on a pickle jar..

 

[huntinfool]

When you took your old deck out the boat flexed. With the new deck the boat is not in the same position as before, hence why the seat seems stretched. You might be able to loosen the deck screws and put a strap on the boat and pull it back together, then tighten the screws.

 

[StephenSharpe]

It never had an old deck, im gonna try to take a video of what im talking about haha

 

[T Man]

Drill a few small holes and shoot some low expanding foam in under the seat. The low expanding foam is not closed cell, so dont use it for flotation foam, but a little at the top of the seat will be fine.

 

[Mojo^]

The condition you described is called "oil canning". The decking is probably holding the sides of the boat rigid not allowing it to flex which, under normal conditions, would pull the aluminum tight on the bench. There are several things you can do to prevent oil canning. You could cut a small relief somewhere on the bench which will allow the metal a place to move to rather than popping back and forth but that could weaken over time and maybe even result is cracks. I guess it all depends on how bad it's oil canning. If you can remove the bench, you could build some bracing out of aluminum square tubing to put under the seat of the bench. I did this when I rebuilt my Grumman and the increased stability it provided was far more than I expected. It's just a simple ladder design that installed with pop rivets under the bench seat that really gave it a lot more strength for my 360 lb. fat-a$$ and even allowed me to install a hatch in the bench without loosing any structural strength.