Underskining toon ?

[rcl700]

Anyone see any other material other than sheet aluminum to underskin a toon? I was looking at some glass board sheets at lowes today and they look like they would do the job & an cost alot less.

4' x8' Frp fiber board. .090 thick.

Seem strong, water proof, mold proof, cheep $26 a sheet.

What are your thoughts?? Should I try it??

Should be alot less drag.

 

[Kitchen363]

Re: Underskining toon ?

Sound like a cheap solution, just wonder how it would hold up the the "flex" of the boat over time. If a huge piece peeled off while in the water this could cause quite a few problems.

 

[cc350]

Re: Underskining toon ?

I feel that aluminum will be about the only thing to hold up. Problem being that whatever you use to fasten the sheeting with would eat through anything but aluminum due to the flex of the deck joists maybe a large aluminum washer and rivets might work?

 

[Captain Craig]

Re: Underskining toon ?

Anyone see any other material other than sheet aluminum to underskin a toon? I was looking at some glass board sheets at lowes today and they look like they would do the job & an cost alot less.

4' x8' Frp fiber board. .090 thick.

Seem strong, water proof, mold proof, cheep $26 a sheet.

What are your thoughts?? Should I try it??

Should be alot less drag.

Any ideas if this would work?

Thanks

 

[lmuss53]

Re: Underskining toon ?

I'm starting the second season with 1/8 fiberglass sheeting under mine. No issues yet, but not a whole lot of hours either. I got mine at a surplus place, really cheap. Time will tell.

 

[lmuss53]

Re: Underskining toon ?

CC makes a good point about the sheets wiggling around. I'm going to watch for that. I used #8 self drilling screws.

 

[rrhodes]

Re: Underskining toon ?

I am not sure if I can post a link so if I am breaking a rule I am sorry.. You can get Aluminum sheets here http://www.aircraftspruce.com/catalog/mepages/3003_alsheet.php

Prices are not too bad.

 

[5150abf]

Re: Underskining toon ?

The reason they use aluminum is because of the tremendous beating the under deck takes, you are dealing with thousands of gallons of water at a high force and speed, I have even seen aluminum pulled off if there is any gap at all for water to get under.

You can try anything but don't be suprised when it gets ripped off, maybe if you backed it with some strips of wood to keep the sheet from flexxing between the crosmembers and use lots of screws like every foot.

 

[tbagger]

Re: Underskining toon ?

Newbie question, why would you put a skin on the underside? There's about a dozen toons at our club no one has this. Thanks

 

[James R]

Re: Underskining toon ?

Please forgive my ignorance. I have just purchased a 1987 pontoon and this is my first foray into pontoons. I have other boats aluminum and fiber glass.
This pontoon shows only Ply underneath. What is "underskining" ? I am about to undertake a rebuild so any help I get will be most appreciated.

 

[Jeep Man]

Re: Underskining toon ?

Newbie question, why would you put a skin on the underside? There's about a dozen toons at our club no one has this. Thanks

I will attempt to answer your question, and James' as well. A pontoon boat, unlike a regular hull splashes it's wake up under the deck as well as to the outside. This under deck water hits the ribs causing drag and is responsible for loss of speed and increased fuel consumption. Many have claimed a 3-5 mph gain by underskinning. Underskinning is adding sheet of material, usually aluminum,under the ribs which creates a smooth surface underneath. Other materials can be used. Personally, I have sourced large 1/8" in. thick plastic sheets that I can get for free that I'm going to use. I will be attaching with self tapping screws through aluminum strips.

 

[Cubbyblue22]

Re: Underskining toon ?

The only thing I can think of would be poly plastic sheeting. It usually doesn't warp like wood and I would think stay sturdy and have a good length to it. I don't have it on mine but just a thought.

 

[James R]

Re: Underskining toon ?

Thanks for that piece of information guys. Now I am informed and will look into the underskining.

 

[lmuss53]

Re: Underskining toon ?

I'm kinda curious why anyone thinks 1/8 inch fiberglass sheets, installed overlapping front to back with screws in the crossmembers at about one foot spacing would be any more inclined to pull off than aluminum?

I am watching for screw heads to pull through, and will be the first to report it if I see it, but beyond that I don't think this will fail, or I wouldn't have used it. This stuff destroys saw blades and drills, and is VERY hard and dense. I had to cut it with the "nibbler" from work, which is a tool used to cut sheet stock, including steel, up to 3/16 inch.

I have mine back off the boat right now and based on this post I will put a small stainless flat washer on each screw when I put it back on. My friend works at a mobile home factory and is getting me some #10 aluminum alloy self tappers to reinstall the sheets with.

If this gets torn off the bottom of the boat while underway I will be extremely surprised, but my sheeting is about 30% thicker than the ones the OP is talking about.

 

[5150abf]

Re: Underskining toon ?

The problem I see is the sheet flexxing between the crossmembers and tearing the screw out, it may not but could, alumiunum of coarse doesn't tear.

 

[imported_John o]

Re: Underskining toon ?

The problem I see is the sheet flexxing between the crossmembers and tearing the screw out, it may not but could, alumiunum of coarse doesn't tear.

(I tried, I really tried to just let it lay, but aluminum does tear, just not at any loads we'd be expecting to see on a pontoon. :^) )

 

[Jeep Man]

Re: Underskining toon ?

I'm kinda curious why anyone thinks 1/8 inch fiberglass sheets, installed overlapping front to back with screws in the crossmembers at about one foot spacing would be any more inclined to pull off than aluminum?

I am watching for screw heads to pull through, and will be the first to report it if I see it, but beyond that I don't think this will fail, or I wouldn't have used it. This stuff destroys saw blades and drills, and is VERY hard and dense. I had to cut it with the "nibbler" from work, which is a tool used to cut sheet stock, including steel, up to 3/16 inch.

I have mine back off the boat right now and based on this post I will put a small stainless flat washer on each screw when I put it back on. My friend works at a mobile home factory and is getting me some #10 aluminum alloy self tappers to reinstall the sheets with.

If this gets torn off the bottom of the boat while underway I will be extremely surprised, but my sheeting is about 30% thicker than the ones the OP is talking about.

I would have a concern with the self tapping aluminum screws. I would have a fear of them snapping off while installing them. Aluminum is very soft. I plan on using stainless steel. I hope to not have any reaction between the two metals. Comments welcome.

 

[lmuss53]

Re: Underskining toon ?

These are an alloy screw, possibly some sort of aluminized steel, (I'm not even sure that is possible) that he said you can draw down TIGHT!!. He has been building these trailers for close to 30 years and I have to assume that he won't lead me wrong.

I am going to watch this sheeting very closely as we go forward here. I will report any problems back to the board, right here in this post.

 

[5150abf]

Re: Underskining toon ?

Well ya, anything will tear if you put enough force on it just ask Southwest but as you said in this application that doesn't apply.

My point was they use aluminum and not fiberglass sheeting because it is more durable, it may work fine, Imuss will let us know how it comes out.

 

[trout74]

Re: Underskining toon ?

question: I get the sheating for under the deck, but do you have to also Sheat the angle between the toons and the deck? that is where it gets tricky, making htat angle. maybe you could opt out of that part, if your not too mechanically inclined??