Composite Decking for aluminum boat?

[NewportSandy]

Ahoy! I recently bought A 1976 mirocraft 16ft deep V. The previous owner installed pressure treated planks as the decking about a year ago. Used SS screws to attach them the the stringers. Ugh! In all the forums I read the new PT chemical is copper based and will corrode the aluminum in no time at all so they have to come out. Instead of marine plywood with resin and creating can I just use compositing decking instead? It's plastic so it shouldn't react with anything.

http://www.homedepot.com/Lumber-Com...splay?catalogId=10053&langId=-1&storeId=10051

 

[ondarvr]

Re: Composite Decking for aluminum boat?

Its weak, heavy and expensive, which of those characteristics sounds good.

At first it looks like a good option, but not many people go that route after they look into it.

The PT should come out, but it can be replaced with many different things from very affordable to $$$$$, it just depends on what you want.

If you want low cost, exterior grade plywood with porch paint will last many years, from there it goes up in $$$$, sometimes at a steep angle

 

[Jlawsen]

Re: Composite Decking for aluminum boat?

I recently discovered, much to my amazement, that many of the high end heavy aluminum boat builders use pressure treated plywood on their decks. When I discovered it on two of my boats I called the guys and asked why. The response was simply that the amount of corrosion is insignificant if there is any at all. Yeah, I was suprised to hear that too.

Two different companies and the same answer? The second question I asked was if the decks were covered under the lifetime hull warranty and the answer was no but any corrosion caused by the use of improper materials during construction would be.

It's important to remember that a lot of folks on here are putting facts togethere based on unrealted or seemingly corresponding research. Most of the boats don't end up in their posession long enough to prove whether the research was valid or not.

 

[jigngrub]

Re: Composite Decking for aluminum boat?

I recently discovered, much to my amazement, that many of the high end heavy aluminum boat builders use pressure treated plywood on their decks. When I discovered it on two of my boats I called the guys and asked why. The response was simply that the amount of corrosion is insignificant if there is any at all. Yeah, I was suprised to hear that too.

Two different companies and the same answer? The second question I asked was if the decks were covered under the lifetime hull warranty and the answer was no but any corrosion caused by the use of improper materials during construction would be.

It's important to remember that a lot of folks on here are putting facts togethere based on unrealted or seemingly corresponding research. Most of the boats don't end up in their posession long enough to prove whether the research was valid or not.

This pressure treated plywood is not the new ASQ formula pressure treating of todays wood, it's CCA (chromated copper arsenate) pressure treated plywood. The old formula before they changed over to the ASQ in 2002.

They still make the CCA pressure treated lumber for marine applications. The plywood is kiln dried unlike the pressure treated you buy at the local home centers.

You will not find CCA kiln dried pressure treated lumber at any of your local lumber yards, it's handled by marine dealers only.

When they changed over to the ASQ formula they took out the arsenic and upped the copper content significantly, this is what causes the corrosion.

My Tracker Deep V came from the factory with the CCA ply almost 15 yrs. ago and it's still like new. The CCA ply does come with a lifetime warranty and is great decking, the best IMO.

You can look at the specs on it here:
http://www.pontoonstuff.com/cca-treated-marine-grade-pontoon-plywood.aspx

 

[Jlawsen]

Re: Composite Decking for aluminum boat?

This pressure treated plywood is not the new ASQ formula pressure treating of todays wood, it's CCA (chromated copper arsenate) pressure treated plywood. The old formula before they changed over to the ASQ in 2002.

I won't argue with you because I can't. There hasn't been any significant field testing to prove either of us right or wrong. Regarding your link to the add... Well, lets just consider that advertising done by someone in marketing and leave it at that. I see a lot of "you shouldn't because it could" but not much of "You can't because it will".

As a side note, you make that statement as if you are in my garage and have removed my decks. I know you aren't there so maybe you work for the folks that make JetCrafts and/or Duckworths.

 

[jigngrub]

Re: Composite Decking for aluminum boat?

I won't argue with you because I can't. There hasn't been any significant field testing to prove either of us right or wrong. Regarding your link to the add... Well, lets just consider that advertising done by someone in marketing and leave it at that. I see a lot of "you shouldn't because it could" but not much of "You can't because it will".

As a side note, you make that statement as if you are in my garage and have removed my decks. I know you aren't there so maybe you work for the folks that make JetCrafts and/or Duckworths.

Have you read this thread?

http://forums.iboats.com/showthread.php?t=514777

It's a "can't because it will" thread.

 

[ondarvr]

Re: Composite Decking for aluminum boat?

jigngrub is correct, the two types of ply are different. Check the recommendations from suppliers of normal PT to the lumber yards or box stores, stainless steel or properly treated fasteners are your only options in a wet envornment, in big letters it says do not use around aluminum. Even some of the aluminum boat builders that use the correct marine PT put a barrier between the plywood and aluminum.

 

[TruckDrivingFool]

Re: Composite Decking for aluminum boat?

To the original question of the composite - I'd avoid it just on the fact that that stuff get HOT in the direct sun and slick when wet.

 

[NewportSandy]

Re: Composite Decking for aluminum boat?

Its weak, heavy and expensive, which of those characteristics sounds good.

At first it looks like a good option, but not many people go that route after they look into it.

The PT should come out, but it can be replaced with many different things from very affordable to $$$$$, it just depends on what you want.

If you want low cost, exterior grade plywood with porch paint will last many years, from there it goes up in $$$$, sometimes at a steep angle

Yup, once I actually looked at it it was too heavy. Not horribly expensive considering the no maintenance part though.

I was thing exterior grade plywood with 2 part poly sealer ( or marine resin) with the pink foam insulation underneath attached by construction adhesive.

 

[ondarvr]

Re: Composite Decking for aluminum boat?

You need to use epoxy if you don't plan on glassing it, polyester resin is brittle and weak when used alone.

 

[NewportSandy]

Re: Composite Decking for aluminum boat?

You need to use epoxy if you don't plan on glassing it, polyester resin is brittle and weak when used alone.

True. I think I might just remove the deck and add a a thin plastic sheet between the stringers and the PT lumber. That's the only area they touch. They are dried out anyway. When I remove the deck I'll take a pic of the stringer to see the damage done if any. The deck has been in contact with the stringers for over a year so it might add some evidence to the "whats happens when box store PT lumber is used on a tinny" posts seems to be all over this board.

 

[The DM]

Re: Composite Decking for aluminum boat?

So very glad I read this thread! I am getting my boat back from the blaster next week, and will be starting the flooring project next. I would have gone right to HD or Lowes and made the mistake of buying the regular PT plywood and not known about any possible problems with it and my ol' aluminum boat.
Thanks to all.

 

[Piece715]

Re: Composite Decking for aluminum boat?

I looked at the composite materials and found them to be too heavy as well. So I did some research on the new bamboo decking that is becoming more readily available; rot resistant, fire resistant, etc. Not easy on the pocket book but couldn't find too many cons for the bamboo stuff, not sure of the weight. I decided to go with cedar decking in aluminum Sea Nymph. It's super light weight and naturally rot resistant. Only con is its very soft so if you will be constantly dropping stuff on it I would steer clear, but so far its been holding up well despite the ongoing restore. I added Penofin Red Label penetrating oil finish which offers UV protection

 

[Piece715]

Re: Composite Decking for aluminum boat?

On a side note... I also went with the insulation board for replacement foam.

 

[NewportSandy]

Re: Composite Decking for aluminum boat?

Great job! Looks awesome!

 

[sprintst]

Re: Composite Decking for aluminum boat?

Sharp looking boat man.

 

[NewportSandy]

Re: Composite Decking for aluminum boat?

Looks sweet! I think im going to square aluminum tube, and oak plywood with aluminum brackets.

 

[jigngrub]

Re: Composite Decking for aluminum boat?

Looks sweet! I think im going to square aluminum tube, and oak plywood with aluminum brackets.

Make sure your plywood is exterior grade with the waterproof glue. Cabinet grade ply isn't made with the waterproof glue.

 

[NewportSandy]

Re: Composite Decking for aluminum boat?

So I pulled the PT lumber off the Stringers and found..... no damage! So all the BS in all the forums here are just that. There are the new PT lumber also. So if there was barriors between them they would have been fine. It has been in salt water for a year and the PT was screwed right to the stringers. Maybe the paint saved it? There was a little corrosion around the screws holes because the previous owner used SS screws with no grease. So the record though I'm still going to use aluminum tubes with plywood. The lumber added about 90 pounds of weight.

 

[robert graham]

Re: Composite Decking for aluminum boat?

Ahoy! I recently bought A 1976 mirocraft 16ft deep V. The previous owner installed pressure treated planks as the decking about a year ago. Used SS screws to attach them the the stringers. Ugh! In all the forums I read the new PT chemical is copper based and will corrode the aluminum in no time at all so they have to come out. Instead of marine plywood with resin and creating can I just use compositing decking instead? It's plastic so it shouldn't react with anything.

http://www.homedepot.com/Lumber-Com...splay?catalogId=10053&langId=-1&storeId=10051

My Express Jon boat came with a 1/2" thick fiberglass reinforced light green colored foam board for flooring...looks like it came in 4'X8' sheets, been very good, light weight, bouyant, held down with screws, seems pretty much indestructable, as I have dropped my 20lb. anchor on it several times and it just bounced. I don't know the name of this foam board, but maybe the Express Boat folks would give you some information on it.....