# Questions about installing pedestal seats



## mcontrer82 (Mar 23, 2012)

Hi, I am new to this forum and I have been looking around for the past few days. I have a 1436 alumacraft and I wanted to add some seats. I have seen several of you who have done that by adding the plywood to the bench. This is the way that I want to add them. I just had a few questions before I attempt to install them this weekend. This is what I have purchased already. 

https://www.academy.com/webapp/wcs/stores/servlet/Product_10151_10051_10773_-1?N=581132421

https://www.academy.com/webapp/wcs/stores/servlet/Product_10151_10051_10755_-1?N=581132421

https://www.homedepot.com/h_d1/N-5y...&langId=-1&keyword=toggle bolts&storeId=10051


My questions are (1) Should I use 1/2" plywood or 3/4" plywood? (2) Do I need to find stainless steel toggle bolts or are these fine? (3) What size drill bit do I use and how do I make the center hole for the pedestal base? (4) Do I just drill through the plywood and the bench seat at the same time or are the holes in the bench bigger? Any advice would be helpful. I just don't want to mess this up. Thanks.


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## bobbyb (Mar 23, 2012)

Your Base plate takes a 1/4" Stainless Steel Bolt - Round Head if you want it to look pretty. Use nothing but stainless steel. 

Here's how I did mine - there are several methods:

My floor is 5/8" plywood. 
Underneath Ply Plate: I cut a piece of 5/8" ply - approx 2" larger than the plate your installing square. I coated it with Spar Urathene - (3 coats).
I attached the ply plate to the underside of my existing floor with stainless screws and contact cement
Using a Hole saw I made my centre hole - if you don't have one just use a drill and drill a series of holes so that the "stem" fit's snug - Not Loose.
Coat the inside of that Hole with Spar.
So now I have a strong, 1 1/4" thick section and I set the plate.
I Marked the base plate plate holes with a pencil, then drilled the holes using a 1/4" Bit.
Set the plate in, bolts in, and on the underneath I used a stainless washer, and a stainless nut with plastic insert - I did not want it backing off. Tighten down the plate and I was good to go.
Why do all this? I do not want to mess with it again  
Note: If you have existing carpet where the plate sits, before drilling the holes - use reverse on your drill to "open" the carpet. If you just drill you may end up with your carpet around your drill bit :shock: 

good luck with it,
bobby


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## jigngrub (Mar 23, 2012)

If I understand mc82 correctly, he wants to install a pedestal base on a metal bench seat with a piece of plywood between the two.

If I was doing this job, I'd use 3/4" plywood sealed with 4 coats of exterior grade spar urethane.

I wouldn't use toggle bolts at all, I would use stainless "T" nuts on the back side of the plywood to hold the 1/4-20 stainless screws that hold the base to the plywood. 

I'd use 3/16 diameter blind (pop) rivets to fasten the plywood to the metal bench seat.

This is what "T" nuts look like:





The barbs on the back of the nuts dig into the wood as you turn the screw, when the screw is tight and the nut is completely embeded in the plywood cut the screw off flush with the back of the plywood. then fasten the plywood to the metal bench seat.

Use a hole saw in a drill to cut the pedestal hole in the plwood and bench, position your plywood on the bench where you want it and tape it securely to hold it while you drill through the wood and metal at the same time. Use a hole saw just a fuzz bigger than the diameter of your pedestal.

After your hole is drilled in the wood and metal affix the wood to the base with the "T" nuts and screws.

FRasten the wood with the pedestal base attached to the bench with the 3/16 dia. rivets on 3" centers.

Go fishin' and enjoy your new seats!


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## mcontrer82 (Mar 23, 2012)

Thanks for the tips and yes I am trying to put the seats on the existing jon boat bench seat. Any other advice would be helpful. Thanks.


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## parkerdog (Mar 23, 2012)

Depends on your budget but I've been wanting to cut a hole in the front of my seat and install one of those doors with tackle storage behind it. (already have the pedestal)
If you went that way you could put your plywood under the seat with the base bolted through the top into the ply. 
It would be out of the weather, cleaner installation and give you some storage if you wanted it.

There are several variations of the tackleboxes out there or even just a hatch door.

https://veada.com/boat-storage/two-drawer-slimline-tackle-box.html


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## xbacksideslider (Mar 23, 2012)

I used zinc threaded inserts. Nominal 7/16 fine thread on the inside; they are maybe 5/8 on the OD. See pic. If you use the correct drill size they will go into your seat plywood very tight but glue will both lubricate them during insertion and then lock them into the plywood.

Then stainless 7/16 fine thread countersunk bolts slathered with anti-seize fasten the seat base plates to the seat top.


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## mcontrer82 (Mar 24, 2012)

Thanks for the information and ideas. I had another question. What size hole saw is needed to cut the hole into the bench seat?


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## parkerdog (Mar 24, 2012)

mcontrer82 said:


> Thanks for the information and ideas. I had another question. What size hole saw is needed to cut the hole into the bench seat?



You said you already have the pedestal mount? Just measure it. Or did it have any instructions with it?


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## mcontrer82 (Mar 26, 2012)

I am having a hard time deciding how thick of plywood to use for my pedestal mounts in my 14' jon. I am not planning on putting in a floor. I am just going to put carpeted plywood on my bench seats and attach the pin pedestal seat mounts. I want it to be solid but I do not want it to be too heavy for the boat. Should I use 1/2" or 3/4". I already have some 3/4" but like I said I am not sure if it would be too heavy. What do you all think? Thanks.


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## Dino (Mar 28, 2012)

mcontrer82

I'm in the same boat so to say; I'm looking to install the same bases in a Alumacraft V16. I was thinking about using 1/2" marine grade plywood and cover it with marine floor vinyl from Cabela's. I was going to used SS screws to mount the plywood to the existing seats and then mount the seat mount on the plywood. I do like the t-nut idea but I'm not sure what the advantage of using the blind rivets over ss screws and this is only because I just don't know. Just as a note the back seats of the V16 are plywood with the floor vinyl with ss screws. Please let me know if you have made progress.

Thanks 

Dino


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## mcontrer82 (Apr 2, 2012)

Hey guys, so I finally went ahead with my seat install. I used the 3/4" non-treated plywood. I coated it with 2 coats of the spar urethane. Then I glued on the outdoor carpet from lowes and used toggle bolts to mount it to the bench seat. I am really happy with how it turned out. The only issue I had was while applying the carpet on the middle bench seat some of the glue looks like it came through the carpet a little (first two pictures). Not too bad but noticeable to me. I am hoping it looks a little better when it fully dries. I am not sure why this happened or if this has happened to anyone else but the only thing I could think of is that I put too much glue in spots or I didn't spread it out enough. Oh well, all in all I am very happy with this mod. Let me know what you all think.


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