Seat Base Install

[BigTerp]

Thinking about how I'm going to mount my pin seat base to my rear bench? I'm debating on installing a hatch in my rear bench as well, but may forgo that idea for now. Without access beneath my rear bench, how would you install my seat base? Screws right through the rear bench? Doesn't seem like that would be quite sturdy enough. If I do end up installing a hatch, I'll have access to be able to use bolts, washers and nyloc nuts. But without this option I'm not sure what to do.

 

[marshman]

this may get frowned upon around here, but...

stainless machine screws thread in to aluminum very well...they will "tap" their own threads, and hold good...

i have mounted quite a few pin bases that way...and, i would do another if i were in the situation to need to...

i like to drill a pilot hole just a hair smaller than the screw, and then just run the screw in with a screwdriver bit on the drill...

the base has 6 holes, use 6 screws...

now....dont get me wrong, i think i would be more comfortable knowing some nuts were on the bottom, but ive never had any problems...

***my applications were just for seats and the short pedestals...my exwife sat in the chair on a pedestal mounted that way no problem...and lets just say, that was a good "load" test...

 

[BigTerp]

Thanks marshman!!

I'm guessing I want self tapping machine screws?

You say short pedestal? When underway the seat will be installed in the "low" position with just the seat mount sticking into the base. While fishing I'll be getting a 11" or so pedestal to use. You think the extra height from an elevated pedestal would put to much stress on the screws as opposed to nuts and bolts?

 

[marshman]

BigTerp » 29 Jul 2013, 14:12[/url]"]Thanks marshman!!

I'm guessing I want self tapping machine screws?

You say short pedestal? When underway the seat will be installed in the "low" position with just the seat mount sticking into the base. While fishing I'll be getting a 11" or so pedestal to use. You think the extra height from an elevated pedestal would put to much stress on the screws as opposed to nuts and bolts?

nope...the 11 inch pedestal is what i call the short pedestal...the seat with no pedestal would be no pedestal...haha...


i didnt use self tapping screws...just regular stainless machine screws... stainless is hard compared to aluminum, they will tap their own threads...just get a good hole, just a tad smaller than the screw(17/64 for a 1/4 inch screw if i remember correctly)... and also if i remember correctly, its a 2 inch holesaw youll need for the big hole.. before you set the base down, squirt a ring of gorilla glue around the hole....

i wouldnt do that for your floor pedestal...for that one i like the idea that the other guy suggested about running the bolts threaded up from the bottom....id put some locktite on them and let it set...then just bolt the pedestal down with some nuts on top...

 

[BigTerp]

Thanks. I'm planning on picking up my hardware tonight, so the quick response is appreciated.

I'm still on the fence on what to do about the captains seat. I REALLY don't want to buy anymore aluminum. I have plenty left over. I'm thinking I may just bolt the seat through the floor and through another piece of sheet. I'd have to do this before I install the floor. I may also throw a piece of angle down on each side of the pedestal, under the floor and between the ribs. This will give me something to rivet my floor down to around the seat base. Hopefully making it more sturdy.

 

[Ranchero50]

Machine screw or bolt threads should usually have 1.5x the diameter of the bolt in the base material for minimum sustained hold. So a 1/4" bolt needs 3/8" of metal to hold in or you run the risk of the threads distorting and pulling out. Vibration and dissimilar metal exacerbate this.

For the pin base on the bench seat I would use mount the pin base to a 12" x 12" x 1/4" load plate and use 1/4" wood style screws and some 5200 to glue / hold the plate to the bench seat base. Drill a 1/8" pilot hole for each screw and let the screw deform the metal into a threaded hole.

The narrower pin base alone in the .100 seat is going to flex once you add a 10" pin extension. Sooner than later it'll pull out and you'll have to do something better.

 

[Panthrosan]

I went with Rivnuts installed into the aluminum and then plywood directly on top of that and have the bolts go through the plywood and screw into the Rivnut.

 

[BigTerp]

Thanks for the responses!!

I ended up ordering a hatch for the bench (12" x 14"). So I'll have access below the bench. Planning on using stainless bolts, nylox nuts and washers. Should I throw a piece of .125" aluminum sheet under the bench for my bolts to go thru?

 

[marshman]

BigTerp » 30 Jul 2013, 21:28[/url]"]Thanks for the responses!!

I ended up ordering a hatch for the bench (12" x 14"). So I'll have access below the bench. Planning on using stainless bolts, nylox nuts and washers. Should I throw a piece of .125" aluminum sheet under the bench for my bolts to go thru?

yupp!! a piece of plywood would be fine too....just something to distribute....

 

[RiverBottomOutdoors]

Take a look at the SliderG5s. I have one and love it.

Jonah

 

[Brine]

Should I throw a piece of .125" aluminum sheet under the bench for my bolts to go thru?

Take a look again at Ranchero's reply above about guidelines for a backplate. I'd follow that advice.