# Mounting seats to aluminum tank type bench.



## 0331grunt (Apr 2, 2008)

I have a 14' aluminum V-Hull with the tank type bench. Would like to mount seats. I've tried the clamp on type, but when you lean back or side ways they pop off. I do not want to drill holes in the bench to mount them because the aluminum doesn't feel that thick and I can't get under the bench to get some of the foam out to bolt them on. Any idea.


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## BlueWaterLED (Apr 2, 2008)

If it were me, I would get a few pieces of 1/4 inch thick aluminum and use them as backing, then use stainless steel screws to mount that bench. I know you don't want to drill, but if you hit some rough water it will be nice to know your bench is going nowhere.


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## 0331grunt (Apr 2, 2008)

Place the 1/4" aluminum on the bench and drill a holes thru the 1/4" aluminum and the bench. Is this correct ? Thanks again.


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## BlueWaterLED (Apr 2, 2008)

0331grunt said:


> Place the 1/4" aluminum on the bench and drill a holes thru the 1/4" aluminum and the bench. Is this correct ? Thanks again.



That is what I would do, yes.


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## 0331grunt (Apr 2, 2008)

Thanks...Just making sure.


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## Old Bill (Apr 2, 2008)

You could also do it the old Redneck way...by adding 3/4-inch plywood across the top of the seat, and then mount the seat base to the plywood.

Oh! You did say that you didn't want to drill holes in the seat, didn't you?

Forget everything I wrote! :wink:


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## 0331grunt (Apr 2, 2008)

Old Bill...The Alumium is so thin on the bench I was worried if I mounted the seat to it, after time those screws would work their self loose. On yours did you use 1/2" plywood and screw the plywodd to the bench.
Thanks.....


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## Old Bill (Apr 2, 2008)

0331grunt said:


> Old Bill...The Alumium is so thin on the bench I was worried if I mounted the seat to it, after time those screws would work their self loose. On yours did you use 1/2" plywood and screw the plywodd to the bench.
> Thanks.....



No, the Richline boat I own came from the factory with a 3/4-inch plywood board bolted to the two sides of the aluminum front and rear seat risers. I'm not sure if "risers" is the proper term? Flotation foam is in the seat cavity, under the plywood bench top. There are about 10 or 12 bolts installed. 

Now, I don't really have any idea how long screws would hold in thin aluminum, if you actually attached a plywood top across the top of your seat. However, since all most all stress on the screws would be shear force...ie. against the side of the screw, I believe that the screws would hold for many years. The more screws...the better and longer holding power. If I was doing this I would use 3/4-inch plywood and at least eight 1/4-inch SS screws as shown in this bad drawing. 






Now, I would use for a seat base one of the Kingpin deck bases, as shown in the photo of my boat's center seat. However, installing one requires that 4 screw/bolt holes and a large center hole be cut in the seat! But, these bases are very strong and the boat seat can be rasied or lowered by adding a pole pedestal.

One good thing about doing this type modification is that the plywood can be easily replaced should it become wore. A little dab of 3M 5200 sealer on the screw threads will make them very, very hard to remove! I prefer to use 3M 4200, but it is very hard to find in small quantities.

Maybe an engineer will step in now and give his/her thoughts on this subject?


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## 0331grunt (Apr 2, 2008)

Old Bill....Sounds good to me....I"m gonna give it a try..
Thanks again for all your help...


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## ACarbone624 (Apr 2, 2008)

I made mine out of 3/4" Ply, a piece of 4x4 and some 2x4 pieces. I ratchet strap them to the bench and they are solid.


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## Popeye (Apr 3, 2008)

You said you didn't want to drill holes because you felt the metal was too thin. You aren't opposed to drilling holes if they will hold are you?

Toggle bolts






The problem with toggle bolts is if you want to remove the screw, the toggle part stays behind and then you won't be able to get the screw back in. Here's a handy trick my dad taught me. Drill your holes and when you insert the toggle, squirt a bunch of RTV (silicone adhesive) on the toggle. When you tighten it up the silicone will adhere to the toggle and under side of the seat. You can remove the screws and when you want to replace it, the toggles will still be there waiting for you. You could also shoot some Great Stuff expanding foam in the holes just before you insert the toggles as it cures faster than RTV.

Just my 2 cents worth


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## Jim (Apr 3, 2008)

flounderhead59 said:


> Drill your holes and when you insert the toggle, squirt a bunch of RTV (silicone adhesive) on the toggle. When you tighten it up the silicone will adhere to the toggle and under side of the seat. You can remove the screws and when you want to replace it, the toggles will still be there waiting for you. You could also shoot some Great Stuff expanding foam in the holes just before you insert the toggles as it cures faster than RTV.



Great tip man! :beer:


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## Old Bill (Apr 3, 2008)

flounderhead59 said:


> You said you didn't want to drill holes because you felt the metal was too thin. You aren't opposed to drilling holes if they will hold are you?
> 
> Toggle bolts
> 
> ...



That's a neat trick that will come in handy for several of my projects. Thanks for the tip! :lol:


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## 0331grunt (Apr 3, 2008)

Great idea ...


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