what kind of wood on a jon boat project?

[grover]

I'm starting to restore a 1448 Lowe jon boat. Not sure of the year. I've removed all of the carpet, plywood, and wiring. I'm down to orignal boat to start with a clean slate. I'm trying to figure out how to put in a floor over the ribs and frame a raised deck. I know I can't use treated plywood because of the copper and aluminum corrosion issues. I don't know if the floor should be made with marine plywood or regular exterior grade plywood coated with some sort of polyurethane to protect it. I plan to use 1/2 inch and I don't think anything needs to be used between the ribs under the plywood. I've seen others use foam board to help make it a little more solid but I'm afraid it would eventually become water logged and just add a lot of weight. I've seen some use 2 x 2 untreated lumber to frame for a raised deck. I would think this would rot away in a few years. I've also seen some use aluminum angle which sounds like the best choice.

Anyone want to give me some advice on any of my ideas?

 

[Ictalurus]

You can use regular exterior grade ply, just make sure to coat it several times with you choice of paint or spar urethane. Make sure to get the edges real good. Aluminum works well too. A combination of aluminum bracing and wood decking is a popular choice.

Edited to say that you can lay down some blue or pink board foam between the ribs under the deck. This will dampen sound (would be like hitting a drum every time you dropped something w/o it). You can also use 1/4" ply over foam to save on weight.

 

[momule]

Why don't you do it right and stay with aluminum? You know you should and you'll regret it if you don't.

 

[jl008018]

I am a fan of the marine grade plywood. Cost a bit more but worth the investment if you plan on keeping it around.

I went the treated 2x4 route for the support as I did not have access to the aluminum. The little extra weight from the 2x4s up front for the platform actually helped getting the boat on plane faster.

The marine grade vinyl worked out great for me as it is very durable and a breeze to clean.

 

[lckstckn2smknbrls]

The pink or blue foam insulation panels are a closed cell foam that would take years of being constantly submerged in water to become water logged. Any extra foam you add to your boat will only help in case of a floatation emergency.

 

[richg99]

ji008 Did you say treated????

 

[grover]

Spar urethane was what I was trying to think of, not polyurethane.

Ictalurus - I don't think we have 1/4 inch marine plywood locally. Just 1/2 and 3/4.

lckstckn2smknbrls - I'll check out the closed cell stuff. I had a hot tub once who's lid got very heavy because I think it adsorbed the moisture from the hot tub.

jl008018 - Nice looking work. What is marine grade vinyl?

So marine grade plywood does not need coating? Another thing I am thinking about is instead of carpet is I might go with some sort of truck bed liner directly onto the plywood deck. My thoughts on this are it would hold water and hooks will not get stuck in it.

 

[perchjerker]

marine grade vinyl is just what it states. It a floor covering made out of vinyl that goes on the floor, like carpet, its sold on rolls by the sq yard

I am using it in my build, I think its a lot better and easier to install than carpet

 

[richg99]

Yep, re marine grade vinyl. I am using \/this\/ stuff.

Now, it is NOT as "fluffy" or thick as their picture makes it appear. I am happy with it. I put it directly over 1/4 exterior plywood, which was mounted on top of thin aluminum flooring, which has Blue Foam under it.

I could send a scrap to anyone who wanted to see it up close. richg99

https://www.defender.com/product3.jsp?path=-1|2276179|2276198|2276202&id=23772

 

[jl008018]

-richg99-

I did say treated

Learned it after the fact that aluminum and treated wood are a bad mix.

However, the wood is sitting on top of the wood wrapped in vinyl floor and is only touching the aluminum seats. I did however, put 3 coats of exterior paint on the wood and painted the seats prior to attaching the wood.

Think I should be OK?

 

[richg99]

I have no way of knowing what would be OK or not. Guess if it was mine, I'd want a thicker barrier than coats of paint.

It probably would keep me awake at night a number of times. Then, one morning I'd get up and re-do the whole thing .... just so that I could sleep.

I am like that about crazy stuff. richg99

 

[lckstckn2smknbrls]

Marine grade plywood will rot just like any other plywood if not sealed properly.

 

[jigngrub]

I'm a big fan of the kiln dried CCA pressure treated marine grade plywood. The Chromated Copper Arsenate treated plywood won't corrode aluminum like the ASQ treated will.

The CCA plywood comes with a lifetime warranty and won't rot even if it gets wet, but I still seal it with 4 coats of marine grade epoxy resin. Wet plywood is very heavy and takes forever to dry out IF it ever dries out.

You can use regular exterior grade plywood, and I strongly suggest using a marine grade epoxy resin to seal it with. Urethanes aren't that durable or long lasting... but the marine grade epoxy resin hardens the surface of the plywood and is like a sheet of Lexan on top of your decking.

Another real good grade of plywood is MDO (medium density overlay), MDO is what they make exterior signs with and is used in concrete form work for construction because of it's durability and water resistance.

 

[richg99]

You sound very knowledgeable about woods. I claim no special expertise.

So, it is probably just the old fuddy duddy in me that says .... if it has Copper in it!..I am NOT going to use it on MY aluminum boat.

Heck, some guys here won't use stainless steel screws on their aluminum boat.

Better safe than sorry.
regards, richg99

 

[Johnny]

yep - that's the Fuddy Duddy talking right there :LOL22:

 

[uncndl1]

Have you considered the plywood that is in between Marine and regular Exterior as far as price?
https://www.uslumberinc.com/hdo.html
It seems that many people here are using this product. From reading, I think you will still want to seal the cut edges with something.

 

[riverbud55]

Why don't you do it right and stay with aluminum? You know you should and you'll regret it if you don't.

I wouldn't say that aluminum is the ""right"" way to do it for everybody,, myself I would never have a aluminum floor , to hot in the summer and to cold in the winter drop a 1oz sinker sounds like ya set off an atomic bomb ,,, trust me if I wanted a aluminum floor I would have one seeing I own a sheet metal fab shop,, my North River came with vinyl covered MDO, had to pull a section up not long back and looks new front and back after near 10 years ,,,, I would look at mdo or hdo,,,,, the one thing about vinyl gets slicker then snot when wet , gets real bad with flathead catfish slime,, problem solved with some cheep bath/kitchen rugs from walmart

 

[grover]

From what I'm reading it sounds like MDO or HDO plywood is the way to go. The local Menard's has 1/2 inch MDO at $50 a sheet. It may not even need coating so that is a plus. I wonder if painting or treating with some Thompson's would be enough. I guess sealing it with epoxy resin would further insure weatherproofing.

 

[lckstckn2smknbrls]

You can ix up your own sealer from 1 part boiled linseed oil 1 part spar varnish or urethane and 2 parts mineral spirts.
On another boat site it's called the Old Timers Formula and it is used quite often to seal exterior grade plywood with great results.

 

[-CN-]

Yep, re marine grade vinyl. I am using \/this\/ stuff.

Now, it is NOT as "fluffy" or thick as their picture makes it appear. I am happy with it. I put it directly over 1/4 exterior plywood, which was mounted on top of thin aluminum flooring, which has Blue Foam under it.

I could send a scrap to anyone who wanted to see it up close. richg99

https://www.defender.com/product3.jsp?path=-1|2276179|2276198|2276202&id=23772

I've seen many new boats that come with a mystery surface on their decking from the factory. I've always wondered what it was, figured it was some sort of spray-on like a bedliner, but it is smoother than a bedliner, and looks exactly like the "Shark" or the "Storm Gray" colored marine vinyl shown in your link. I wish I'd known about it before I did carpet!