mounting swivel seats on an enclosed bench seat?

[bowrider98]

Is there a more secure way to mount a swivel seat base to an enclosed bench seat in an aluminum fishing boat other than using self tapping sheet metal screws or rivets? The bench seats are fully enclosed and I can't get a nut on the bottom of a screw. Is there something similar to a drywall anchor? thanks.

 

[Pony]

They make clamps that the swivel bolts to that clamp onto the bench seat.
http://www.iboats.com/Wise-Boat-Sea...3365483--session_id.529986744--view_id.375790

I used to have a 14fter with bench seats, but the clamps I used were homemade. Each had two threaded rods that went underneath the bench with wing nuts on the ends to tighten them up around the bench.

 

[MTboatguy]

I have something similar to these:

http://www.iboats.com/Wise-Boat-Sea...9754157--session_id.314406030--view_id.375790

As far as bolting them, they make a product called a nutsert that you can use when going through flat plate, when you tighten down, it will expand, but they wear out pretty quickly and get loose.

 

[Woodonglass]

Please excuse my poor drawing but I believe this would be a good way to secure your swivel seats to your benches. Simple to construct from 3/4" Plywood and some 1/2" x 5" stainless steel bolts and some T-Nuts and deck screws. Use some Black rubber matting glued on the wood to help grip the aluminum bench.

 

[jigngrub]

Please excuse my poor drawing but I believe this would be a good way to secure your swivel seats to your benches. Simple to construct from 3/4" Plywood and some 1/2" x 5" stainless steel bolts and some T-Nuts and deck screws. Use some Black rubber matting glued on the wood to help grip the aluminum bench.

I can see someone getting dumped on their noodle in that thing, but I'm not sure if it'll happen before or after they bang their knee on that tightening knob.


The removable clamp brackets are ok if you don't want a permanent installation and you don't weigh over 100 lbs., but they'll loosen and slide from side to side and will need to be tightened regularly.

I personally would go for a much stronger/secure/permanent installation.


I think a full width piece of plywood mounted on top of the aluminum bench would look nice and fastened down with the 1/4" dia. rivets it would be very secure, or you could do individual base plates. You could do a clear varnish or urethane sealer for that exposed wood look... or you could go with deck vinyl, carpet, or paint.

The plywood will be fastened securely to the bench, the seat base will be bolted securely to the plywood and you won't have to worry about anything sliding or moving around or coming unclamped.

You have a few options now, but this is the way I'd do it if it was mine.

 

[MTboatguy]

I don't know, I weigh in at about 235 and have not had to tighten my clamps since I put them on..

 

[Woodonglass]

A bit more clarification on my clamp drawing. The drawing doesn't show nor do the instructions state, but there should/would be 2 or 3 clamp bolts The bolt heads would stick out but a cover could easily be fabricated to cover them to avoid any "Knee Bumping" if needed. I'm in agreement with MTboatguy that once the clamps were tightened sufficiently they would easily sustain the pressures placed on them by a 300 lb fisherman in a Fishing type seat. I may have to build some just to check it out. This will be an inexpensive and interesting project. It'll be fun too. If I lean back and the clamp fails and I fall on my keester I'll be sure and video that too!!!!