Can resin be applied to plywoood decking

[mkthbk]

I was reading some past messages about sealing the plywood being used for the decks and many advised not to, beause it could trap the water in the wood causing it to rot.

I was wondering if you can brush a thin coat of resin used for fiberglassing. Just a thin coat on top, bottom and all edges, Wouldn't this prevent the wood from absorbing water which many say adds a great deal of weight to the boat until it can dry out.

This idea has also caused me to wonder if if you couldn't also use fiberglass and resin and with the added strength maybe be able to use thinner plywood due to the reinforcement of the fiberglass and resin to cut down on some of the weight of the plywood and reduce the whole wood rot issue at the same time.

I'm new so mabe this has already been talked about.

Sure would like to have some input from the more expierenced out there.

Thanks

[Catt]

Many bass boats used plywood coated or reinforced with fiberglass; G3 aluminum boats still use plywood for their decks. I don't know where people get the idea you can't use treated wood with aluminum because there are afraid it will cause galvanic corrosion or even trap water. After 15 years in the Aerospace industry as a Manufacturing Engineer I can assure you that is a total myth. It you really want to cut down on weight use sheet aluminum of at least two gauges thicker than your hull; carpeted aluminum decks are just as quit as wood with ½ the weight.

[DaveHawkins]

Yes, you can use resin to cover your plywood...and if done correctly, you will have a sealed, waterproof deck.

Your 2 choices of resin would be to use either un-waxed polyester resin with cut strand mat fibreglass (CSM) or you could use a low viscosity epoxy resin and just coat it on by itself.

The polyester resin will be cheaper than the epoxy.

[cart7t]

The resin for fiberglass work, like the stuff Walmart sells, is not the ideal covering I'd use.  That particular resin doesn't have a lot of rigidity as a stand alone coating.  It would be much better to use epoxy resin.  

[fishfordollars]

The preparation would be the most important feature. It will work fine as long as you prep each surface accordingly. To creat the correct bond the surface prep has to be done. Do not cut corners. The above posts are all correct. Good luck.

[SissySticks]

Honestly, I used resin on my boat and if I do it again (likely) I'll use Thomson's water seal.  The resin is messy and not easy to work with.  Also, you don't have to use 3/4 in ply unless you're not planning to support the deck properly.  5/8 works fine and is lighter and easier to find in odd-ply, which I also recommend.  If you use the Thomson's I also wouldn't say you need treated ply, since you'll be treating it yourself.  You should be able to pick up untreated 5/8 5-ply for ~$20/sheet.  Also, sometimes the department of roads will give away old Interstate overpass signs, which are a very heavy-grade aluminum and work awesome for boat decking when coupled with aluminum angle supports.  Cheers

[Catt]

The Ole Road Sign trick, haven't heard that in years but it is an excellent choice since it's made of 6061 T6 which has a very good corrosion resistance, finish ability, plus excellent welding. Plus the strength level of 6061 T6 is approx that of mild steel.

[DaveHawkins]

Another good option is a product sold in Lowes, called Termin-8H20.  It is only about $15.00 a gal.  It protects from rot, mildew, pests, warping, etc..It says can be used below or above ground great for docks, boats, lanscaping timbers, etc.  This is actually the stuff I am going to be using on my 14' v-hull when I get to the transom, deck, and floors.

The problem with the department store resin is that it is waxed polyester resin and as it cures the wax comes to the top.  Good for a top finish...but needs to be heavily scuffed for any additional coats.

[Zum]

I wouldn't use treated plywood.

"Standard carbon-steel, aluminum, or electroplated products must not be installed in direct contact with CA or ACQ treated wood".This is a quote from a site I'm not aloud yet to provide.

"Perhaps the most important point to keep in mind relating to copper-based wood treatments and galvanic corrosion is to avoid aluminum flashings altogether. Aluminum corrodes quickly in the presence of high copper concentrations"another quote off of a different site

Does anyone know if G3(New Orleans)has a class action lawsuit against them because of this?

"years ago when the EPA banned the amount of Arsenic used in CCA treatment and they increased the copper concentration to take the place of Arsenic."from another boating forum

[Catt]

Ok here we go again

If the aluminum is anodized and painted the contact with Wolmanized® wood products will not cause corrosion. If the aluminum is not treated what takes place is galvanic corrosion.

Galvanic corrosion is an electrochemical reaction between two or more different metals. The metals must be different because one must be more chemically active (or less stable) than the others for a reaction to take place. When we talk about galvanic corrosion, we're talking about electrical exchange. All metals have electrical potential because all atoms have electrons, which have an electrochemical charge.

Galvanic corrosion of the more chemically active metal can occur whenever two or more dissimilar metals that are "grounded" (connected by actually touching each other, or through a wire or metal part) are immersed in a conductive solution (any liquid that can transfer electricity). Anything but pure water is conductive. Saltwater, freshwater with high mineral content, and polluted freshwater are very conductive, and conductivity goes up with water temperature. That's one reason why boats in Florida experience more corrosion than boats in Maine.

To stop galvanic corrosion; clean the aluminum surface to remove all dirt, old paint and oxide from the surface. Apply a coat of acid etch primer following the mixing and application instructions to the letter. Within 24 hours of applying the etch primer, apply the topcoat finish. This will be an automotive grade or marine grade polyurethane coating. Use a good quality product to protect all the prep time and elbow grease you invested prior to the topcoat application.

Another cure for galvanic corrosion is to simply apply a thin layer or faying seal with some type of sealant.

[Zum]

That was a good read.

Seems like alot of work to clean,remove paint,proper primer,proper paint then cover all your work with treated plywood...that might rub and cause galvanic corrosion is the end:)

I know you can also put a barrier to stop the corrosion...that apparently doesnt happen?

I have seen some pictures of what treated wood did to a boat where it rubbed the paint off.100 gauge aluminum,half through floor,ribs pretty much all the way through...not good.

Anyways,I don't think I'd use it.

[Low_Budget_Hooker]

carpeted aluminum decks are just as quit as wood with ½ the weight.

and will NEVER hold water.  The only draw back is cost.

My decks are 3/8 cdx (cheap and thin) with a coat of resin.  I replace them every few yrs. but only to keep the boat looking fresh, not because I have to.

The $30-40 is worth it for all fresh carpet and stuff

[Catt]

carpeted aluminum decks are just as quit as wood with ½ the weight.

and will NEVER hold water. The only draw back is cost.

My decks are 3/8 cdx (cheap and thin) with a coat of resin. I replace them every few yrs. but only to keep the boat looking fresh, not because I have to.

So let me get this right as a Low Budget Hooker you replace plywood, resin, fasteners, carpet, carpet glue, plus your time & energy every couple of years under the pretense of saving money?

Even if the price of sheet aluminum is high in you neighborhood you could as mentioned obtain old road signs & have it welded in place never to been replaced. To this dumb Cajun that's Low Budget Hooking!

[Low_Budget_Hooker]

no, I think you misunderstood the reasoning,lol.  I replace them mainly because of the carpets.  They get nasty dirty and beat up, especially the front deck one where Dirk comes out of the seat, that first foot plant.  It gets thin right there.  Plus, the scents and dyes spilled on the bench seats, etc.  I'm a slob and it's a jon boat.  For $30-40, I can not "worry" about keeping it clean and pretty and abuse it as the tool it is

But...

I never even considered street signs,lol,...matter of fact, 1 highway exit sign from 95 and I can deck the whole boat in 1 shot!!

Best thing is,...up north, they aren't all riddled with buck shot!  

[Fishing Rhino]

I was reading some past messages about sealing the plywood being used for the decks and many advised not to, beause it could trap the water in the wood causing it to rot.

I was wondering if you can brush a thin coat of resin used for fiberglassing. Just a thin coat on top, bottom and all edges, Wouldn't this prevent the wood from absorbing water which many say adds a great deal of weight to the boat until it can dry out.

This idea has also caused me to wonder if if you couldn't also use fiberglass and resin and with the added strength maybe be able to use thinner plywood due to the reinforcement of the fiberglass and resin to cut down on some of the weight of the plywood and reduce the whole wood rot issue at the same time.

I'm new so mabe this has already been talked about.

Sure would like to have some input from the more expierenced out there.

Thanks

There are two types of fiberglass resin, polyester and vinylester. Do not use polyester resin as paint. Contrary to popular belief it is not waterproof. It can and will absorb water.

In a relatively short time, checks and cracks will develop as the plywood shrinks and swells. Epoxy is a much better choice. It is waterproof and more durable than polyester resin.

I make fiberglass race car bodies and body panels. I use polyester because it is the cheapest, and perfectly suitable for something that does not have a long life expectancy.

If it rains on a panel, or water gets on the side without a gel coat, it will turn a milky white. Will water leak through the panel? No, but bear in mind the panels vary in thickness from 1/16th to 1/8th" thick.

Rolled, brushed or sprayed, you'll have nowhere near that thickness, and water will penetrate to the wood, destroying the bond.

Below is an excerpt from an article about the advatages of epoxy over polyester and vinylester resins.

What contributes to this better value..?

Epoxy resins have performance advantages over polyester and vinyl

esters in five major areas:

n Better adhesive properties (the ability to bond to the

reinforcement or core)

n Superior mechanical properties (particularly strength and

stiffness)

n Improved resistance to fatigue and micro cracking

n Reduced degradation from water ingress (diminution of

properties due to water penetration)

n Increased resistance to osmosis (surface degradation due to

water permeability)