Excellent Article In Bass And Walleye About The Comparisons Of Wood To Composites In

boat construction.
Very well written, and if you read between the lines, very enlightening!
Shocking to see some of the boat manufacturers admit how much is marketting versus fact.
As I've said and believed from day one (article agrees), it makes more difference how it's intsalled than anything.
Also amazing to me at how many people think all that foam core will not rot or saturate with water like wood does.
Pound for pound, wood, especially ply, is tough if not impossible to beat if "properlly" used.
One of the manufacturer's even stated that they tested all available composites for its ability to hold a screw w/o stripping.
None worked as well as wood.
Some are using a method called "pulltruding" (I think) where they use multi layers of multi types of cloth/mat, then saturate it with resin before running it through a combo press/oven.
It comes out very strong and will hold a screw comperiable to wood but is heavier and much more expensive.
When most of the top race boat builders (have to be the lightest and strongest) are still using plywood (some for the complete boat) for m.boards and stringers, and balsa core for skins, that's all I need to know.
Check it out, is an excellent read.
They also have a shot of the new Merc 4 stroke which I think is uglier than a box of rocks! Looks like two cowlings stacked on top of each other, yuch!
They divuldge more "beliefs" than I've read before. That small article along with the Merc written "guide to O/B's" (very well written also)as a pull out in the magazine, here's aprt of what they say/think:
It's an in-line six but all Merc instead of the new GM as many thought.
Although it didn't sound like it, Merc said it was "pressure injected" meaning super charged, or turbo.
In their O/B guide, they said that since the 300X won't pass the '06 EPA/Carb rules, it's going to be all Opti and four stroke, and they thought that 300+ HP's would be easy in the forseeable future.
The next 12 months may be interesting in deed.
I find it very ironic and kind of neat that their future may be with an in-line six! how appropriate would that be??
Gary

Concerning the strength of wood...........


A Trident II D5 Submarine Launched Ballistic Missile weighs approx. 130,000 lbs. It is lifted and moved from place to place vertically when necessary. The lifting fixture is attached to a structure known as the Nose Fairing. The fairing is made from laminated Sitka Spruce less than 1/4" thick. The wood core structure of the fairing is covered with a substance similiar to gel-coat. No question about the strength of wood here. There have been nearly 100 test launches of these missiles and not one single failure. The whole structure is subjected to extreme forces during launch impulse and subsequent hydrodynamic as well as aerodynamic peturbations. Now if we could only figure out how to get the wood to not be hygroscopic we would have it all.

huh?
I'm guessing, porus, or susceptable to water?

able to absorb water. Dot 3 through 5 brake fluid is also hygroscopic. Not sure about the higher grades. :cool:

Readily taking up and retaining moisture.

It's easy to make 300 hp with a 4-stork OB the trick is making it light.

If you want to make wood non- stroboscopic just add an air pump. Water can't get in unless the water pressure is greater than the air pressure. Just make sure the intake for the compressor isn't near water.

...are designed to penetrate the wood, and make it impervious to rot. Might be kind of painstaking to treat all the wood before laminating it, but it is a solution. :cool:

As you learn in materials science classes at engineering school, wood is actually a composite in itself and a laminate of wood and polyester is a composite of a composite (wood) and polyester.

So the whole wood vs. composite discussion that is popular in boating circles is scientifically incorrect...

And I agree with the points above: Wood is an excellent material.

Quote:

---

Originally posted by Rickracer
...are designed to penetrate the wood, and make it impervious to rot. Might be kind of painstaking to treat all the wood before laminating it, but it is a solution. :cool:

---

Is this the other stuff? http://www.rotdoctor.com/boat/Bmain.html

Is that a sign of aging? Let's see, there's wrinkles, gray hair, and I forget the other ones........:D
Actually CPES (Clear Penetrating Epoxy Sealer) is what I was trying to remember.

still being able to glue/galss or paint it after treatment.
When I was building hydroplanes we tried everything.
The best "wood preservetive" we found was a product called "cuhprenohl" (sp?) and it went on like water but staurated very deep into the wood.
The negative was, nothing would stick to it afterwards.
I built one and used the new "miracle" epoxy everyone was talking about, but it was too thick to saturate vey far, and peeled easy.
My favorite is and always has been thinned varnish. Glue still won't stick to it but you can apply it to the inside of the hull before installing the deck. We would use polyurethane (not actually varnish) and start off with it thinnned like 50% for the first couple coats, and then reduce from there.
On rot specifically, they say it actually starts as a fungace in the wood from the start. It needs heat and humidity to spread, almost like mold.
The "Git-Rot" I have seen has been more for repair than prevention??
My dad used to have wood cabin cruisers when I was a kid and I remember my dad always joking about buying stock in the company as long as he owned a wooden boat.
The stuff saturated the wood surrounding the damaged area and turned it rock hard and then you filled in the damaged area with a "Marine Tex" type epoxy filler.

As for the 300 HP 4 stroke, yep , I know.
Been saying that for yerars! Be interesting to see how far they can take em??
wonder how much a turbo or super charged 250/300 4 stroke I/O, Imean O/B :D will cost:eek:
I still say too, give them 2 or 3 years of use in the field and the neglect and abuse that our motors go through!
Going through one of our motor's is bad enough, but wait to get a quote for one of those bastards!!

when I started the re-coring project on my Vector, I researched the alternatives quite a bit.
Someone on this board (Techno?) turned me onto a marine website that did a study on it and it was very educational.
Basically what I/article said at the begging of this post.
That site showed pixs from storm damage of many high dollar yachts that were built with various cored construction.
The first myth they blew away was that the "foam" would not rot/deteriorate.
They were showing the sides of hulls with 2 and 3' holes in them but after being inspected, they found the majority of the area in the hulls to be totally de-laminating! (and not from the storm damage)
They/it basically said for strength vs weight, it's almost impossible to beat balsa.
I really appreciatted the people in the Bass/Walleye article having the stones to tell the truth on part of the myths involved.
Several of the company owners said that they much prefered wood construction but that the market had been brain washed (sounds kinda like the 4 stroke O/B gig doesn't it) into thinking wood was bad, period!
One owner quoted I beleive $600. additional cost for the same boat with no wood.
Several also hi-lighted the strenth per lb myth of composite vs/wood. Basically they said if both materials are of the same strength, wood is the lightest and that most of the claims contrary to this was purely marketing! (they also pointed out how some of the composites are described vs reality, again, marketing)
They also taked about the variables such as storing a boat on-shore with a drain plug in, or with the tongue down and the plug out and allowing it to fill full of water.

Great post, how do I get Bass and Walleye Mag, and do they have a websight?

Thanks

http://www.amagarea.com/Detail/NS-QPHH&LPAATNTQDPIH

later.sid

I've never known wood to be a problem as long as the transom holes are sealed up good, unless the manufacturer did something brilliant like leaving exposed wood without glassing it in, like they did under the transom cap on the Glasspar G-3. I have seen a couple of boats with rotted wood floors that got lumpy after about 20 years. But it's hard to say what the true origin of the problem was; the life of boats is typically directly proportionate to the IQ of the owner(s). I see a lot of boats sitting outside in snowstorms with no cover, gee I wonder if stuff like that contributes to these types of problems.