Composite stringers

[chambers1517]

I recently bought a 2005 Caravelle 207. Are there any advantages of wooden stringers and transom over composit? Will composite last forever or will it also rot? I can find no wood in this boat should it last longer than a boat with wood?

 

[ziggy]

Re: Composite stringers

i don't know any specs of wood over composit. but i do know that there are many many folks repairing the wood stringers and transoms and decks/soles of there old boats. it would seem to me that no wood has got to be a winner for longevity. so far, i'm a happy no wood boat owner too. my 75 aristocraft is billed as wood free (though i think there is minor amounts of wood in them). in lieu of composits aristocraft used a inner hull liner along with foam. which in aristocrafts case is the downfall. the foam gets wet. that said, from what i hear from aristocraft is that the repair for soggy foam is to R&R the foam, and cover the hole ya cut to go get it... that sounds better and less labor intensive than R&Ring transom, stringers and deck to me... i'd think your new boat would have foam too. but if the foam gets wet, i can't think that the wet would attack the compost parts of your boat. in aristocrafts case. i've not heard of wet degradeing the fiberglass, i've no idea if it'd attack a composit... but i'd think not so much..
that's my inexpert guess..

 

[Knightgang]

Re: Composite stringers

Are you refering to composite lumber, or a purly synthetic compisite.

Composite lumber still has wood fiber in it that can rot, however, I would think that it would take longer for it to rot than regular lumber.

A synthetic composites would not rot, in my opinion...

 

[Bob_VT]

Re: Composite stringers

Many of the manufactures have moved away from using wood or use very little in new construction. Even Bayliner changed their methods and have great construction practices now. Your boat sounds like a new generartion of construction and only time will tell.

This is a C&P from the Caravelle site which appears promising

NO WOOD HERE

Caravelle likes to point out that the 207, like all of its boats, is 100 percent free of wood in its construction. Wood is great construction material and has plenty of excellent qualities ? cost effective being one of the best. The potential to rot, however, is not one of the best qualities of wood.

While many manufacturers still use wood in their boats with great success, be it specially pressure-treated plywood for use as a deck material or lightweight balsa wood totally encapsulated in fiberglass and resin for use as a support stringer, we have to admit that the wood-free moniker does give Caravelle a selling point that many others can?t honestly claim.

Caravelle uses a material called Nida-Core in most places you would typically find wood in a boat?s construction. Nida-Core is a synthetic honeycomb material that has a number of advantages over wood and can be found in the construction of automobiles, surfboards and even satellite dishes. Because it?s a synthetic product, however, we wouldn?t be surprised to learn that it?s more expensive than wood.

Treat the boat right and it should provide you with years of low hull maintenance.

 

[allpoints360]

Re: Composite stringers

I've never used composites for stringers. The trade off is weight and cost. Composite is heavier and more expensive.

I am not aware of a product that is impervious to water and has the same weight as wood. But I would pay more for it if I could get it.

 

[metriccrescentwrench]

Re: Composite stringers

Composite is heavier and more expensive.


More expensive, yes. Heavier, no. (Maybe you're thinking of the plastic deck boards sold at home improvement stores.)

Just one example, some folks doing restorations are using a material called Coosa Board which is manufactured by Coosa Composites. It's about 20% lighter than the plywood it's designed to replace, but very high dollar.

Myself, I've used wood for both of my boat restorations and am just making sure to encapsulate it in fiberglass, using epoxy resin (which is far superior to polyester), and ensuring that water always has a path to drain into the bilge.

 

[tboltmike]

Re: Composite stringers

Might want to check out the Parker website. They are a quality manufacturer and make a case for wood.

http://www.parkerboats.net/pages/faqs/index.jsp

 

[Knightgang]

Re: Composite stringers

I can see their side of the issue, however I feel it is more of marketing hype to try to sell boats, as they all do. If I had the choice or a wood built boat and a wood free built boat, I would take a wood free.

I have asked myself, other than cost, why not just build stringers completely out of fiberglass and leave the wood to strickly deck and transom areas. I do not know the answer and maybe Parker Boats has hit it with overall strength over time...

 

[metriccrescentwrench]

Re: Composite stringers

Might want to check out the Parker website. They are a quality manufacturer and make a case for wood.

http://www.parkerboats.net/pages/faqs/index.jsp

I call BS on their claim that foam will break down in a foam cored stringer. That MIGHT be the case using cheap pour foam as the core, but there are plenty of other foam types available that would stand up perfectly well to hard use and flexing. Fiberglass airplane wings with a fiberglass skin over a PVC foam core have been in service for 30 or 40 years with no problems. Also, stringers built from Coosa board wouldn't even need to be glassed (other than attaching them to the hull) and they'd last forever.

I would imagine that as costs come down the use of wood in boats will subside. Now there's nothing inherently wrong with a properly constructed boat with wood in it, the problems arise with improper use and care (adding accessories to the transom without properly sealing the holes, letting boats sit outside uncovered, etc.), but if the costs were nearly equal the all composite boats would definitely get the nod.

 

[tboltmike]

Re: Composite stringers

Metric,

I have no fish to fry with Parker, just saw their site awhile back and thought it might add interest to the string. I think I did.

My 35 year old Arrow Glass has wooden stringers and transom and had gotten water in the double bottom from deck screws rotting. Only had localized rot were a nail was used to join a 1x2 to the top edge of the fir stringer. The transom is resin coated ply as are the stringers. The deck is glass matted on top and resin coated on the bottom side. The deck only rotted in 2 inch round areas about the rotted screws.

I think that speaks pretty well of wood construction.

I did use a plastic plate outboard of transom to cover and seal old transducer screw holes and to mount new ones. No rot there either.

Mike

 

[metriccrescentwrench]

Re: Composite stringers

Metric,

I have no fish to fry with Parker, just saw their site awhile back and thought it might add interest to the string. I think I did.

My 35 year old Arrow Glass has wooden stringers and transom and had gotten water in the double bottom from deck screws rotting. Only had localized rot were a nail was used to join a 1x2 to the top edge of the fir stringer. The transom is resin coated ply as are the stringers. The deck is glass matted on top and resin coated on the bottom side. The deck only rotted in 2 inch round areas about the rotted screws.

I think that speaks pretty well of wood construction.

I did use a plastic plate outboard of transom to cover and seal old transducer screw holes and to mount new ones. No rot there either.

Mike

My panties tend to get all wadded up when someone speaks misinformation about fiberglass/composite construction. I've built a fiberglass airplane, and am deep into my second major boat boat restoration .... for some stupid reason I enjoy working with fiberglass.

If Coosa board wasn't so darned expensive I'd have used that for both of my transom repairs, but I just can't justify spending nearly $200 for a sheet of the stuff when I can get nice AC exterior plywood for around $25.

IMHO, a non-wood boat would definitely be superior to a boat with wood transom and stringers, mostly from the standpoint that it would withstand owner neglect better. With proper care our wood transom and stringers will be just fine, we just have to realize that water is not our boat's friend.

 

[tboltmike]

Re: Composite stringers

My panties tend to get all wadded up when someone speaks misinformation about fiberglass/composite construction. I've built a fiberglass airplane, and am deep into my second major boat boat restoration .... for some stupid reason I enjoy working with fiberglass.

If Coosa board wasn't so darned expensive I'd have used that for both of my transom repairs, but I just can't justify spending nearly $200 for a sheet of the stuff when I can get nice AC exterior plywood for around $25.

IMHO, a non-wood boat would definitely be superior to a boat with wood transom and stringers, mostly from the standpoint that it would withstand owner neglect better. With proper care our wood transom and stringers will be just fine, we just have to realize that water is not our boat's friend.

"...I enjoy working with fiberglass."

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