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Old 06-30-2013
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Re: Bob Perry's take on Wolfenzee's dream boat

Quote:
Originally Posted by Brent Swain View Post
Bob
I never suggested you shoot any boat. I suggest you go out to a remote place and try a shot at a 23 inch diameter fir log, then try it on a piece of 3/8th inch mild steel plate, and compare the two for impact resistance, similar to the impact of a sharp rock, then determine who is the liar when stating that wood is stronger. ( reality vs numbers jugling)
Yes. I believe that my boats are far superior to stock plastic and wood boats for full time cruising.
No, I dont believe one should give preference to a designer who doesn't believe strongly in what he is designing.
Yes, I would like to read of your vast ocean cruising expereince, which you had before you began designing for others ( or since for that matter). I notice you make no comment on that. Wonder why?
Caught a good Southeasterly in here, waiting for a good northwesterly to get me to the good swimmin on Cortes. No, I dont spend my time in an urban office. I spend it out cruising, in the real world. Keeps a guy in reality, away from the fantasy land of number jugling.
Heat wave forecast. Wunnerful!
Another classic. This assumes that since you personally do not understand the science, the science must be "juggled". But even debating on the gut reaction level of go out and shoot something, I will go back to points raised in earlier discussions on this topic.

As I have said before, if the prime criteria for selecting a material for a one-off, custom built boat is low cost, speed of construction and impact resistance steel is not a bad way to go, but if you factor in inherent hull weight, then there are better ways to go.

Take impact resistance for example, you use the example of shooting bullets at steel vs wood. To begin with, in the hull construction examples that I have cited in past discussions, the wooden construction would have a Kevlar sheathing. Kevlar has come down in price so in earlier discussions I have shown that you could, buy the plywood, Kevlar laminate and epoxy resin to build a hull deck and much of the interior for less than the cost of steel hull in one of your boats.

When it comes to impact resistance, as I have also shown in the past discussions,there is a pretty big difference between a high speed, small area impact like a bullet vs a slow speed impact like a sailboat hitting a rock ledge. In the case of a high speed projectile, Kevlar has become the standard armor material, replacing steel in helmets,body armor,and vehicles offering a combination of better stopping power and much lighter weight. And this selection of kevlar by the military is by group whose methods of testing and real life experience is far more rigouous and percise that plinking at random pieces of steel and old stumps in the wilderness.

In fairness, steel does do much better in low speed impact where it does a good job distributing the impact to a larger area than it does in a high speed projectile style impact. But even in low speed impacts, Kevlar composites or kevlar over wood composites still offer better puncture resistance when compared by weight.

And while you may not care about the relative weight of your hulls, to me any hull weight savings can be used for some mix of being able to carry more supplies and extend range, or more ballast and increse stability, or reduce weight to allow better performance.

As I have also pointed out, the composite skin could be continuous to avoid leaks. I mentioned an acquaintance who developed a technique for blind fastening fittings without having a fastening opening for water to penetrate.

But lastly there is no reason that a custom boat builder can't cherry pick ideas, doing a composite hull with custom fabricated fittings made from scavanged or salvaged materials in much the same way that you also advocate.

What you are getting called out on in this discussion is the all or nothing approach you advocate, and you unwillingness to address the specifics of these types of discussions, instead putting forth asymmetric arguments that sound good but which do not make sense when compared on a more even balanced analysis.

Respectfully,
Jeff
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Last edited by Jeff_H; 06-30-2013 at 08:21 PM.
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