New deck, fishing boat material choice?

[Larry Edgerton]

I have a 17' fishing boat that has a plywood deck that is going bad. I am going to replace, will not be wood, was thinking aluminum. Carpeted.

Any other suggestions?

[John C Cox]

My recommendation is to go back with Marine plywood...
1. It's already lasted what - probably 20 years? Will you still have the boat in 20 years?
2. It's conventional. If somebody needs to make a repair - they will see the same conventional construction that came with the boat and everybody else already uses.
3. Cost. Even with the price of marine plywood - it's still way cheaper than that much aluminum plate.

It's probably 1/2" marine plywood. Price out 1/4" aluminum plate before you decide..

If you are really unsatisfied with the water resistance - glass over the plywood with 1 ply of 3/4 oz matt and then clear coat it...lay the carpet over that.

But - it's worth asking why it failed in the first place. Often these decks fail because they are holding water inside. Fix that problem and the rotting deck problem stops. Second is getting punctured from above... Screw holes are the worst offenders. Last is laying under a tree and being full of leaves... Leaves hold a ton of moisture on the wood....

Thanks

[Larry Edgerton]

1/4" aluminum, now thats funny. I'd use plywood, but its made out of wood.

[Mac McQuinn]

Larry,
What about "Trex" composite decking?, use same method to hold down as wood. "Select" 1" product is .82" thick though which might be an issue. FIL had it on his docks at the lake, install and forget. *Trex also makes a couple sizes in Fascia board which is .52" thick.
Mac

[John C Cox]

1/4" aluminum, now thats funny. I'd use plywood, but its made out of wood.

What were you planning when you said "aluminum" in your first post?

The reality is that almost all boats are made of wood or have significant wood construction.. And they have forever...

Even "fiberglass" boats generally have a backbone structure, strigers, and transom made of wood...

[James Waldron]

Decks of boats are rarely flat; they are typically crowned (to make sure water runs off). Forming a quarter inch AL plate to fit would be a challenge, even though the curvature would be slight. The boat was designed and built to have a plywood deck and it would be prudent to stay with that for all the reasons noted above as well as the forming requirement. As noted, well protected plywood works very well for very long periods of time. That means good quality coatings, well maintained, and good seals of edges of the structure and any holes for screws, bolts, etc. so water intrusion is prevented.

Some two-part epoxy is your friend. To learn a lot about use of epoxy, including on boats, try West Systems https://www.westsystem.com/instruction-2/. Tried and true info and tried and true products; not the cheapest but none better.

[Mac McQuinn]

Some two-part epoxy is your friend. To learn a lot about use of epoxy, including on boats, try West Systems https://www.westsystem.com/instruction-2/. Tried and true info and tried and true products; not the cheapest but none better.

While as a glue, marine epoxy is a good product, IMO, it's not a good top coat as the lack of UV inhibitors will cause it to basically disappear in a very short time. Epoxy also won't saturate beyond the first glue layer of ply, regardless of the type. Fortunately there are some excellent marine finishes available.
Mac

[Sam Fleisher]

Hello

Check out the forum on tinboats.net. It might give you some ideas, lots of info in the modification part.

I haven't been on it in years but it used to be a pretty active forum.

Have fun

Sam

I can't remember if I'm allowed to post links. If not, someone please delete.

[Mike Cary]

My boat has vinyl instead of carpet. I like it.

[James Waldron]

While as a glue, marine epoxy is a good product, IMO, it's not a good top coat as the lack of UV inhibitors will cause it to basically disappear in a very short time. Epoxy also won't saturate beyond the first glue layer of ply, regardless of the type. Fortunately there are some excellent marine finishes available.
Mac

Lots of boat builders coat with epoxy to seal wood against water intrusion and then top coat the epoxy with uv inhibiting coatings, whether marine varnish or paints. As long as uv protection holds up, epoxy coatings underneath can hold up quite well and stabilize the encapsulated wood substrate.

On the other hand, in my original post, I was speaking of sealing plywood edges and screw/bolt holes, which are essential whether or not one coats with epoxy. Water intrusion into plywood edges is certain and rapid death to plywood.

[Carlos Alvarez]

Marine ply and fiberglass. Seal it completely, then seal it again. You'll never have to deal with it again.

If the deck is bad, check the stringers. If they have water, the boat is done for.

Aluminum will corrode very quickly in this application. Look up "crevice corrosion."

[andy bessette]

Aluminum is a horrible choice: expensive, hot, noisy...

Use marine ply.