Through floor fastening ideas?

[ShoestringMariner]

I’m in the midst of redoing my floors. It might sound odd, but I’m trying to make my sleeper seats unbolt from the floor so I can drop in swivel seats to a Springfield socket mound hidden beneath. Family boat to pro fisher in 2 minute swap.

I want to use stainless T nuts below the floor, say 5/16-18 standard thread. But I’d like a finished ferrule for the top side where the hole goes through the nautolex. a) to keep water out of the drilled hole and causing rot by using set screws or button head SHCS’s to fill the threaded holes when not in use, b) to keep the nautolex from delaminating around the drilled holes.

Any ideas? Does anyone know of any stainless, brass or aluminum inserts I can use?

edit: I found neoprene well nuts that look ideal. If anyone knows of similar with a stainless top flange, please let me know.

 

[Emerger]

I’m in the midst of redoing my floors. It might sound odd, but I’m trying to make my sleeper seats unbolt from the floor so I can drop in swivel seats to a Springfield socket mound hidden beneath. Family boat to pro fisher in 2 minute swap.

I want to use stainless T nuts below the floor, say 5/16-18 standard thread. But I’d like a finished ferrule for the top side where the hole goes through the nautolex. a) to keep water out of the drilled hole and causing rot by using set screws or button head SHCS’s to fill the threaded holes when not in use, b) to keep the nautolex from delaminating around the drilled holes.

Any ideas? Does anyone know of any stainless, brass or aluminum inserts I can use?

edit: I found neoprene well nuts that look ideal. If anyone knows of similar with a stainless top flange, please let me know.

Try a stainless fender washer with a neoprene washer underneath it.

 

[Scott Danforth]

first, back to back seats do not need anywhere near the support structure that a pedestal seat needs. mainly because the physical size of the back to back seat box

you will need to add structure underneath the floor or you will pull what ever screws, bolts, etc you add right thru the floor.

then at that point, build a nut-plate under the floor (t-nuts are generally a 1-time use fastener, then they gall) the nut plate should be something like 17-4PH or 15-4PH to be harder than the fasteners you plan on using.

 

[ShoestringMariner]

first, back to back seats do not need anywhere near the support structure that a pedestal seat needs. mainly because the physical size of the back to back seat box

you will need to add structure underneath the floor or you will pull what ever screws, bolts, etc you add right thru the floor.

then at that point, build a nut-plate under the floor (t-nuts are generally a 1-time use fastener, then they gall) the nut plate should be something like 17-4PH or 15-4PH to be harder than the fasteners you plan on using.

Thanks Scott. I totally agree. The pedestal seats will have a second plate beneath with stainless T-nuts in them. The low dome Springfield flange will be a permanent one time installation.

it’s only the sleeper seats that will be moved in and out periodically. I like the idea of the expanding neoprene well nuts for this. Even better if I can find them with a stainless top flange instead of rubber.

I originally was looking for a sex bolt set up in stainless, but I can’t find them with flanges top and bottom with a tapped hole through the centre.