Bolting 7" pedestal seat to deck

[nickcasa]

Hope someone can assist me here, great forum BTW, I've learned lost. I have a 16' Bayliner Capri, had a new 3/4 marine plywood floor installed over the old one and need to secure my new seats down. They are 7" black pedestals from Gander, however I don't want to use lag bolts and split the wood, Tnuts don't seem strong enough and the Garelick toggle bolt anchors seem to only come in 1/4" X 20 thread and I wouldn't chance that as it seems way too small. I really want at least 3/8 bolt (pedestal has 4 mounting holes) for strength and to outlive me in this lifetime, hehe. Does anyone have any advice as to how I can properly secure these seats down so I can get out on the water? Any help or advice is greatly appreciated. Thank you all.

 

[switzer140]

Ouch

 

[jigngrub]

I have a 16' Bayliner Capri, had a new 3/4 marine plywood floor installed over the old one

Say it isn't true!

You didn't really pay someone to cover the old rotten mush with new stuff did you?

1/4-20 stainless "T" nuts hold my 12" pedestal seat bases very securely... but my 3/4" decking isn't sitting on top of rotten mush.

 

[nickcasa]

Say it isn't true!

You didn't really pay someone to cover the old rotten mush with new stuff did you?

1/4-20 stainless "T" nuts hold my 12" pedestal seat bases very securely... but my 3/4" decking isn't sitting on top of rotten mush.

The floor wasn't really that bad, but it was a bit ugly and I wanted new carpet so they went over it and glassed it in place. Both the top and bottom of the new wood was glassed as well to prevent moisture intrusion. Anyways, the boat goes in the intracoastal and ocean on the east coast of florida and i dont see how 1/4" T nuts would be strong enough to hold the seats down. How many T nuts do you have per seat? Are they stainless steel?

PS - I don't have access to underside of the floor either.

 

[jigngrub]

So what year model is this B'liner?

What size and how many screw base?

I have the 6 screw 9" round bases on my boat.

 

[nickcasa]

So what year model is this B'liner?

2001

 

[jigngrub]

I'd go with a stainless steel #14 pan head sheet metal screw between an inch and an inch and a half long, probably 1-1/2". Predrill your holes and shoot 3M 5200 liberally into the hole before installing the screw.

 

[nickcasa]

I'd go with a stainless steel #14 pan head sheet metal screw between an inch and an inch and a half long, probably 1-1/2". Predrill your holes and shoot 3M 5200 liberally into the hole before installing the screw.

Thanks for the advice and excuse my ignorance, but what is a sheet metal screw going to bite into??? I can't just screw that into marine plywood.

 

[jigngrub]

Sheet metal screws are pretty gnarly with sharp points and Hugh Jass threads:
http://www.homedepot.com/p/Unbrande...etal-Screws-2-Piece-per-Pack-801251/204275414

 

[Woodonglass]

The 1/4" Garelick Toggle bolts will be your best option. One little ole bolt torques out @ about 725 lbs so multiply that by 6 and I think you'd agree that you'll have plenty of holding power for your seats. You'll rip the plywood up before the bolts break off!!!!:joyous:

 

[nickcasa]

The 1/4" Garelick Toggle bolts will be your best option. One little ole bolt torques out @ about 725 lbs so multiply that by 6 and I think you'd agree that you'll have plenty of holding power for your seats. You'll rip the plywood up before the bolts break off!!!!:joyous:

WOW. I didn't think you could get that kind of power from 1/4". I'll definetly go that route then. Thank you very much for the advice and putting my mind at ease.

 

[jigngrub]

Drilling 1/2" holes that will allow water intrusion in a new deck so you can install 1/4" bolts just doesn't sound like that good of a build to me. There's also the matter of snugging the toggles up against the bottom layer of rotten/rotting deck which isn't going to be a very good base for the toggle as it continues to rot... especially with the likely water intrusion from the new 1/2" holes.

 

[shaw520]

You considering T-nuts would suggest that you have access to the underneath,..... aluminum plate on the bottom would be my choice.

 

[jbcurt00]

PS - I don't have access to underside of the floor either.

But, ugh, a new deck over the old is never a good idea, IMO. I hope it serves you well.

 

[Woodonglass]

Follow the instructions that come with the Garelick Toggles. Then as with any holes drilled into the deck coat them and the hardware with a good Marine sealant to Prevent water penetration. If the deck was not that bad as you previously stated then you should be okay for a few years. If it was indeed rotting at least with the toggles you will have some continuous Tightening adjustment ability. Using screws will not allow this.

 

[jbcurt00]

The floor wasn't really that bad, but it was a bit ugly and I wanted new carpet so they went over it and glassed it in place.

Yeah, about that 'not bad' bit:
16ft Bayliner Capri

Well I thought a simple carpet job would be easy....oh boy.....floor was poly resin'd over, chipped all that up, plywood is wet, i can put my finger through it, never would have guessed though as the poly was strong as hell, foam is wet, but i want to get it fixed right, trying to find someone now, i can probably demo it with some pointers....i am in west palm beach should someone want to make some money to take this on for me. I do have a question though, my boat is 2001, same layout as the one pictured....all the grey carpet is gone....is there wood underneath the bow seats as well that could be damaged? it's all fiberglass and gelcoat upfront and doesnt seem so. 2 guys from craigslist said dont rip up the floor as it will harm the structural integrity of the boat, they rec'd to lay plastic type resin sheets over the top of it, for about $800, not sure about that. i really like the boat, engine is great so kinda torn what to do. will the stringers be ok? are they wood in these boats? lots of questions and i really just need some advice. i cant afford a shop to do this, probably be around 3k and i only have 1k to spend on something like this. any advice would be great....thank you all

Unless you bought 2 16ft bayliners in the last 60 days

Again, overlaid deck, not a good plan, IMO.........

 

[jigngrub]

Yeah, about that 'not bad' bit:
16ft Bayliner Capri



Unless you bought 2 16ft bayliners in the last 60 days

Again, overlaid deck, not a good plan, IMO.........

I figured it was some such malarkey as that... wet foam too, nice!

Someone will have fun keeping those toggles tight in a mushy bottom deck.