2005 43’ Trawler w/ Marine Plywood Core in Deck and Pilot House – Major Concern?

Yes its Atkinson shipyard in Nova Scotia. I believe Clarks Harbour.

Thanks for the help

 

"If you Dont allow water ingress, you will not have a problem. Attention to detail when installing deck fittings , waterproofing and distributing load, are the trademarks of a superior boat builder."

This is true , but once the boat is in the owners hands , lack of attention can lead to structural disaster.

This is why I would only consider a solid GRP or foam (no balsa or plywood) core for any boat I would own.

"Stuff" Happens,

FF

 

With few exceptions outboard and sterndrives all have plywood cores in the stern.

 

Yes Gonzo they do indeed and are very subject to water saturation and rot problems due to thru bolting the big motors to the stern or stern drive systems. There are thousands of boats available in Florida alone free of charge with this condition. As one dealer who gave me 4 boats free explained, it's cheaper to give them away than to pay the standard $1000 fee to crush and landfill. One area on those hulls that should be cored with an impervious material or made solid FRP. An important point made here and in prev. posts, that while the origional fabrication on a ply core might be 100% protection, poor equiptment install. later add on's and poor maintenance are usually the downfalls. Geo.

 

Patriot, Clarks Harbour or as they say in that area and in Maine Hab-AR. Down the south shore near Yarmouth, Will check it out---Geo

 

Later add on's and poor maintenance will destroy anything.

 

"Later add on's and poor maintenance will destroy anything."

I have yet to see a well made all GRP boat that could not be brought back due to hull death from lack of maint.

 

Osmosis and major UV damage.

 

Maybe stick built deck and pilot house with 3/4" marine plywood

Steve, both the builder and owner referred to the deck and pilot house as being cored with 3/4" marine plywood. However, when I spoke with the builder he clearly stated that the deck and pilot house were only painted with awlgrip and were not gelcoated. Based on your earlier post it makes me think the deck and pilot house were stick built using marine plywood and Isophthalic resin (not epoxy) otherwise they would have been gelcoated then painted with awlgrip. The solid FRP hull is gelcoated then painted with awlgrip.

I guess I’ll have to research further so I’m clear as to the build method.

I really appreciate everyone’s help as I need to fully understand what we are getting into with this boat before formulating an offer and lining up surveyors.

 

I just walked in the door after a trip to look at a CT41 that is currently on Ebay,a friend of mine is interested in bidding on it, it turned out to be a solid glass hull with a plywood cored deck and plywood stick built deckhouse. The teak deck had been removed and even though the glass is peppered with screwholes the plywood core is very sound, i found zero moisture as the boat has been indoors for a decade and a couple of core samples removed showed no degradation at all, if the core had been balsa it would have been compost.
Patriot,the above is to point out that often times a mixture of methods are used, if it is all stick built i would be suprised if iso resin would have been used at all above the gunwhales as it is a realativly new boat. The iso would have been used in the hull only. It makes perfect sense that the deck/house would have been glassed using epoxy then painted with awlgrip products.
Steve.

 

"if the core had been balsa it would have been compost" - I wonder, should I just throw my boat away or try to salvage it after removing all of the 34 year old Balsa? (It looks exactly as it did when new but I am certain that it will explode or cause the boat to capsize any instant.)

 

My last sailboat, that I sold a couple of years ago, was built in 1969. The balsa core in the deck was perfect; no moisture or rot.

 

Here we go again, yes mark, if your deck has had several thousand 1/8" holes penetrating the top skin for years your core is compost and you might as well throw it away, if however you have managed to keep ALL water out of it,it will last indeffinatly, but then,you know that as well as i do.
Steve.

 

"Osmosis and major UV damage."

And don't forget the Polyester Mites.

 

A boat I raced on had a plywood deck with glass skins, west epoxy, awlgripped. The original builder was very well respected, and the owner could have easily afforded a boat twice the size (the boat basically fit the dock at his house). After about 3 years, the owner simply could not stand the impossibility of maintaining the deck. He swore he would never again own a boat with a wooden deck. He sold that one, and had a new one built with -- you can predict -- all foam core, no structural wood.

A friend I've known for all the 40 years he has been building custom (and some limited production) yachts has told me over and over again, that wood is the little-bit-cheaper, but lots-worse-quality approach. He will build anything anyone wants, but he strongly suggests that boats should have no structural wood, only foam cores and vinylester or epoxy. He builds boats, and he refurbishes boats, so he has seen the effect of balsa and plywood over time.

Of the dozens of yacht builders I know, the only ones who think wood should be used for structural or core purposes are those that simply love wood. For them its not a rational thing, its an emotional choice.

And plywood in transoms of powerboats are very bad ideas as anyone who owns one knows. My first plywood transom needed to be replaced, and now my latest (last!) plywood transom just needed to be replaced. In both cases, water worked its way in from the original holes made by the builder.

Its just too easy for water to get into a wooden core. If you have a choice, avoid it.

And wooden stick built structures are simply a nightmare. Avoid.