Thread: OT - floor in Jon boat help

I would use treated 3/4 plywood,that is what i used in my 1648 it was still in good condition 3 year's later
i just cut it to be a tight fit,no screws.

I agree with cut for tight fit no screws. That's what I did and seemed to work fine. Be aware that treated plywood will react with aluminum and cause damage to your boat

Screws for aluminum boats should be galvanized self tappers. Galvanic corrosion occurs when unlike metals are in contact with each other in the marine environment. The least "noble" metal experiences the corrosion. If you were to use stainless screws, the ribs of your boat will corrode around the screws. By using galvanized (zinc) the screws will corode and are easily replaceable. Use a drill stop to avoid drilling pilot holes through the bottom of the boat. Size the pilot drill 1/32 less than the screw diameter. Put thin self adhesive closed cell foam weatherstripping foam down each rib prior to installation to prevent rattles.

Forget the plywood. For decking material, I would go to BMG metals specialty metals division near Richmond airport (804 226 1024) and purchase 1/8" diamond tread plate. They can cut to size on their shear for a small charge. Under the diamond tread put some foam sheet insulation (from Lowe's). This adds floatation, deadens noise, and prevents chaffing. You could also use 1/16" plate if your are willing to make a tight fit with the foam between the floor of the boat and the deck. 1/16" Diamond plate is what I used on my Ouachita. it gets 33mph with a 25hp running a Ballistic stainless prop. Diamond plate can be easily cut and trimmed (like around the ribs) with a saber or circular saw with a carbide blade as long as you use kerosene as a cutting lubricant.

Forget the carpet. Coat the diamond tread with Cabela's Tuff Coat non skid coating (similar to truck bed liner). Use Cabela's Tuff Coat metal primer on the aluminum prior to application. I use a dilute solution of concrete etch prior to priming. dry and prime immediately. By doing it this way you will have a much lighter, stronger, and longer lasting (nearly permanent) deck that is easy to care for and you can take pride in your boat.

As reference: Fisher Marine uses galvanized screws for deck assembly on their all-aluminum boats. I had one for 27 years, worked great. I have an Alumacraft with decks built in this manner- still holding up well since 1985. I put aluminum decking in my restored 1973 Ouachita. Made the boat lighter, faster, and has been holding up well for 8 years. Even my old 1976 MonArk had its plywood replaced with flat plate aluminum. Unfortunately, I used carpet over it which didn't hold up nearly as well as the decking. I am starting the restoration of a 1970 Tidecraft this summer and it will have Aluminum decking when I am finished.

If you want to see the results on the Ouachita after 8 years of fishing,you are welcome to send me a PM and stop by the next time you are down on the Chick.

Hope this helps

I had same boat, I used dow blue foam board 1" and covered with 3/8 plywood. I bought a floor mat 3'x5' made of rubber that just laid in place all by itself. Weight is everything in a small boat. The foam killed the sound as did the mat. I think I used 4 of the self tapping metal roofing screws, the heads stick out but so small it did not matter. In the front I built a 2x4 frame and put 3/4 plywood to make a flat floor, which I mounted a post and chair. It free floated without any screws. I had my battery in a pocket that keep it in. behind the rear seat I did not put in a floor.

go to tinboats.net all info you need

Flatwater is right. If you plan to mount seats to the floor you are going to have to use plywood.