Structural materials question

supermoix

Cadet
Joined
Jun 16, 2004
Messages
12
Hello again everybody,<br /><br />I've been thinking (for a change) about alternative materials available to rebuild the stringers or transom and general structure on a fiberglass boat to replace fiber-over-plywood normally used, from what i have seen an heard, that combination of materials eventually the wood ends up rotting or flexing in some areas...<br /><br />Woul it be possible to build, for example, the stringers from solid PVC, solid fiberglass or high density polietylene (or any other plastic material) without compromising structural integrity or flexibility of, say, a 20-25 footer fishing boat with outboards?<br /><br />My ideas are running endless, any of you have any ideas that can be shared? (even if they seeem too radical) it can be a welcome for brainstorming for a couple of days.<br /><br />See ya in the water!
 

crab bait

Captain
Joined
Feb 5, 2002
Messages
3,831
Re: Structural materials question

this topic has been beat-to-death.. <br /><br />maybe there is.. but who's an engineer enuff to say..<br /><br />pvc,, is pvc.. plastic.. an what would/could bond to boat with it.. epoxy.??<br />does it intergrate well with other boat materials..??<br /><br />fiberglass,, way to brittle... <br /><br />what else ya got..??<br /><br />tell ya,, wood it's hard to beat.. flex, sheer & compression strenght, workablity, boat material compatibility.. it's pretty much the poop.. <br /><br />but yes it rots.. but not so with cypress, hondruian mohogany,, an a few others.. <br /><br />another way is to prevent rot..i.e. epoxy encapsulation..an do not breech said encapsulation..
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: Structural materials question

Don't forget fatigue resistance. Wood fibers are made for it.<br />Carbon fiber would be an alternative, but it's probably too pricey.
 

BillP

Captain
Joined
Aug 10, 2002
Messages
3,290
Re: Structural materials question

Originally posted by rtamburini:<br /> Hello again everybody,<br /><br />I've been thinking (for a change) about alternative materials available to rebuild the stringers or transom and general structure on a fiberglass boat to replace fiber-over-plywood normally used, from what i have seen an heard, that combination of materials eventually the wood ends up rotting or flexing in some areas...<br /><br />Woul it be possible to build, for example, the stringers from solid PVC, solid fiberglass or high density polietylene (or any other plastic material) without compromising structural integrity or flexibility of, say, a 20-25 footer fishing boat with outboards?<br /><br />My ideas are running endless, any of you have any ideas that can be shared? (even if they seeem too radical) it can be a welcome for brainstorming for a couple of days.<br /><br />See ya in the water!
Solid pvc, poly pro or even solid fiberglass is too heavy to get both stiffness and strength. You can use composites (boards or core) or pressure treated wood to get best strength and stiffness vs weight. Composite costs a bundle and pt wood a lot cheaper. Some believe pt wood will rot if sealed or that resin won't stick to it. I don't see that happening with all the boats that use it.
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Structural materials question

pvc pipe filled with 2-part foam? and wrapped with fiberglass roving?<br /><br />lexan?
 

self taut

Petty Officer 3rd Class
Joined
Jun 25, 2004
Messages
86
Re: Structural materials question

i have been looking int the "alternitive" materials myself. and i found only one thing that i can say for certain.way too expensive for my pocketbook.i decided wood is my best choice but keep looking it may be just what you are looking for if you have the money for it.
 

troyt

Seaman Apprentice
Joined
Jun 25, 2004
Messages
30
Re: Structural materials question

I asked this same question on some non-structural projects, and then did some research. There are alternatives, but they all cost more than good old plywood. Composite products from Diab are probably the closest you will get. Go to www.bateau.com and then look for Divinacell, check the price, and then you will appreciate "good old plywood" even more.
 
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