metal cover under deck

[fish till ya bleed]

I have a 83 Lowe 24 SPT. I purchased the boat with a 100 hp golden meteor Johnson the motor was off the boat and the 100hp was not ever on the boat. Since then I stripped the decking off, pulled the wiring harness and controls that did not match the 100hp, located a set of controls, and built a new wiring harness for her. I was about to put the marine decking on when I found several comments on under skin (I think that's what they called it) anyway covering the cross members with metal to cut down on drag. I have two 4'x12' sheets and two 1'x12' all 4 are .090 thick. I have a few questions about the installation like is this aluminum too heavy too light or just right? How many ss fasteners per cross member? Should I overlap the sheets or just butt them up and seal them with silicone? Do I start at the first cross member and finish at the transom? Do I need any drain holes for what ever water might get between the deck and the plates? BTW I did beef up the mount for the transom where it will support the 100hp. I also located another 100hp Johnson and purchased it for parts but when I ran them both motors and lowers are good if I go ahead and put the 3rd log on it would you put both motors on it? Just a few questions I have any help would be great.

 

[HotTommy]

I skinned my old pontoon boat with 4' x 8' aluminum a bit thinner than yours. The only penalty you'll pay for the heavier sheets is a slightly heavier boat and a little more work getting the sheeting in place while you install them. I started at the back and overlapped each sheet by a half inch or so with the one in front of it. That was to keep spray from forcing its way into the joint while underway. I deliberately did not seal the joints so any water (spray or rain) could drain out easily. I secured the sheets to the aluminum cross members with stainless steel self drilling screws with large heads. .... The result was not dramatic, but it was quieter with less noticeable drag when waves hit the underside of the boat. It might have added 1 MPH to my top speed. It was a worthwhile project. .... BTW, the skin will prevent easy access to the underside of the deck, so don't put it on until you're finished with that part of the project.

 

[Merc40hp]

fish till ya bleed (I luv your handle) I also repowered my pontoon by adding a larger (and heavier engine). As a result of the additional weight, the toon sat lower in the water and the compression of water between the toons (while under way) increased to the point I could feel the cross members slicing across the top of the chop under the boat, creating what I would call micro stalling. It wasn't horrible, more over it was a FAshuttering feeling, as if you were dragging an anchor behind the boat, it was annoying. So I purchased (3) 0.040" sheet stock (4'X10" Alum Sht) and just like Hot Tommy, used self tapping SS screws (and no sealant) to attach the sheets to the underside of the cross members, overlapping them as I went, working from stern to bow. The benefits was instant and worth the cost and labor. No more micro stalling and much less noise.

 

[fish till ya bleed]

Glad you like my handle and you are the first to comment on it for some reason. I hope this does not offend any one but when I finish the pontoon project I am going put a little custom paint on her and I will let the imaginations run wild here but I am naming her "TAMPOON" with "FISH TILL YA BLEED" under it. It should be fun on the water. Back to her I already had the aluminum sheet metal I picked it up on a barter deal so I have nothing invested in it and my only additional cost will be the SS self tappers and the under skin is going on her. It is .090 thick i wish it was a little lighter but I am not in that big of a hurry to fish so it should be fine. Do you remember how many self tappers you used per cross member?

 

[Merc40hp]

I ran a screw in about every 8", including the "L" shaped alum channel I attached above each of the openings where to brackets are welded to the toons (see pic)

 

[fish till ya bleed]

OK About every 8 inches. I was looking at every 6 inches with the thicker sheet metal I may stay with the 6 inch spread. Thanks for the help.

 

[icwingman]

I have a 83 Lowe 24 SPT. I purchased the boat with a 100 hp golden meteor Johnson the motor was off the boat and the 100hp was not ever on the boat. Since then I stripped the decking off, pulled the wiring harness and controls that did not match the 100hp, located a set of controls, and built a new wiring harness for her. I was about to put the marine decking on when I found several comments on under skin (I think that's what they called it) anyway covering the cross members with metal to cut down on drag. I have two 4'x12' sheets and two 1'x12' all 4 are .090 thick. I have a few questions about the installation like is this aluminum too heavy too light or just right? How many ss fasteners per cross member? Should I overlap the sheets or just butt them up and seal them with silicone? Do I start at the first cross member and finish at the transom? Do I need any drain holes for what ever water might get between the deck and the plates? BTW I did beef up the mount for the transom where it will support the 100hp. I also located another 100hp Johnson and purchased it for parts but when I ran them both motors and lowers are good if I go ahead and put the 3rd log on it would you put both motors on it? Just a few questions I have any help would be great.

U must seal the wood or glue the wood n metal to keep wood dry.then screw it in. U have to keep the water out between them. I f u don't the wood will rot out after a few years