Pontoon Boat & Deck Boat Forum

I have a 22 ft thinking about under skinning it....what would be a ball park dollar amount.
only 2 toons.

figure 300.00 . however that will vary with what thickness you use. I used .080. mine turned out great. big difference. wore me out doing it but results were well worth it just in how much quieter it is now. didn't pick up but maybe a couple miles an hour but speed and pontoons are not natural allies..lol/
Now..what I did was I layed down a thick bead of 3M UV4000 Marine adhesive to the cross members. I marked and pre drilled the sheets . I placed the sheets where they went and then secured across the braces in the pre drilled holes with a SS #10 TEK. I put them in with an Impact gun, NOT a screw gun. I have U shaped logs so I didn't need any side filler pieces. There was no need to secure to the side bracing. There those on here that will tell you that the only way to do this is with a rivet attachment as the TEKs can theoretically back themselves out. Yes, possible. Realistically, it would take a lot of vibration and movement for that to happen.
This is where the UV 4000 comes in. It creates a permanent bond of the sheet to the cross brace. All those TEKs can fall out and these sheets are going nowhere. Have extensive experience with this stuff and cant say enough about how well it works. In fact, Featherlite Trailers are constructed with this material for the attachment of all the outer skin.
Here's a pic.

Hope I'm not hijacking this but since Soonertoon brought it up...is the adhesive only for if the screws come out? Or does it need to be permanently sealed? I am contemplating doing an underskin job but I'm sure water will still make its way between the deck and the underskin and I would like it to be able to drain out still and breath a little. I will end up using aluminum rivets as I'm on saltwater and you don't want saltwater, stainless, and aluminum pooling up together unless you are trying to make a battery!

What I am envisioning is something like those old slotted louvers on the rear windows of Firebirds/Trans-AMs with maybe a 1/4" space between the adjoining sheets allowing anything to drain out and a little air to flow through.

Anyone have any thoughts on this?

I underskinned mine without any adhesive, and have not had a problem.
The space between the bottom of flooring and the underskinning is plenty of air space for drying out and ventilation. I would do the underskinning similar to soonertoon's, to make the bottom of boat as smooth as possible. the louvered setup i think would kill the reason for doing it at all.
i didn't use adhesive so i could remove the panels easier when making changes to my boat.
i used self tapping metal to metal roofing screws with rubber washers and all of them are still there after 2 years.

The primary use of the adhesive is to eliminate the loading of the panel being borne solely by the TEK screws. Yes, in the event that they do back out you haven't compromised the sheet attachment. Additionally the sheets being bonded to the braces with the adhesive, become a stressed member. therefore adding a slight amount of rigidity to the overall undercarriage. Screws or rivets alone do not allow for lading to be distributed all across the bracing and do not connect one brace to the other. Now...you CAN remove the sheets. It will take some good effort but you can remove them. The adhesive has some elastic properties in it which do allow for natural expansion , contraction etc.
you will get the same result with adhesive used in conjunction with rivets. They are just harder to put in as compared to TEKs . They DO eliminate 100% any "backout"

Point is...the adhesive is a plus any way you cut it

Sorry if you got offended that was not my intention, I was simply stating the way i did it.
I never said that adhesive was bad. I only stated that i didn't use any and why.

Why use screws that can back out, I used pop rivets.

DWRAT,
I originally put mine in with pop rivets (they held very well)
I switched to screws after i had to remove panels to make changes above the deck, all my stuff top side is bolted down so you have to get to the nuts on the bottom side(my arms ain't that long). So after drilling out all those rivets I said to hell with that and installed screws for future changes planned. and they have worked well for ME.

any idea what a boat shop might charge (alot) ?

I have thought of doing this for my boat. I'm not sure I will see a huge benefit from it as I am only running 75 hp but I like the idea of keeping the underside of the deck dry. Though I doubt I'll try anything until I am all rewired.

[quote="killerkernrich"]I have a 22 ft thinking about under skinning it....what would be a ball park dollar amount.
only 2 toons.[/quote]
I was able to do at 25' twin toon for $100 by getting the aluminum from a local recycler. They cut it to roughly the size I needed. The aluminum was not new, but it was straight and smooth.

[quote="r&s20"]Sorry if you got offended that was not my intention, I was simply stating the way i did it.
I never said that adhesive was bad. I only stated that i didn't use any and why.[/quote]

I didn't take offense in any way. not at all. I wanted to explain the rationalization and benefits from using the adhesive as a backup as well as spreading the loading out over the lateral length of each cross member. As I said, even with rivets the adhesive adds the same benefit . Some will use it some wont. Both ways work.

on my toon 22ft with 60 hp would it be worth the cost??

So does no one ever have issues, or even know if they do, with any water pooling up on top of the underskinning? If I was on freshwater I wouldn't be worried about it but saltwater pooling up there would be bad, especially if I use any stainless screws. Also in Florida where the dang humidity is 90% or better most of the year stuff doesn't evaporate very quickly!

Maybe my louvers description wast good. Here is a crude sketch of what I was thinking.

[quote="Jake_Daddy"]So does no one ever have issues, or even know if they do, with any water pooling up on top of the underskinning? If I was on freshwater I wouldn't be worried about it but saltwater pooling up there would be bad, especially if I use any stainless screws. Also in Florida where the dang humidity is 90% or better most of the year stuff doesn't evaporate very quickly!

Maybe my louvers description wast good. Here is a crude sketch of what I was thinking.[/quote]

I see no issues with that design, except possible "oil canning" noise if there is too much space between fasteners......... and a little extra work, but easier to handle smaller panels.