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are there any alternatives for plywood for the skin on these boats just out of curousity

It's pretty much either ply or cold molded with thin strips of timber, or fibreglass one off methods. Of course there are the traditional methods of boat building as well, but they really get much more difficult to get right.
Why do you ask?

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By the time I have built a boat, I'll be ready to build a boat....

I never thought about that. I guess I always just went with what the designer intended, but for the sake of an academic discussion...

I guess a builder could use any number of products to replace the plywood. Cold molding is essentially building the plywood ON the framework.

I see no reason why aluminum couldn't be adapted for use on mahogany frames.

Sheets of ABS plastic could be made to work.

A few layers of Dacron might even work if well encapsulated with epoxy.

Heck, the Mythbusters used duct tape!

Then there's always animal skins if'n you're an old school type. etc. etc.

The real question is which is going to make you the boat you want and can build. Quality marine grade plywood will have all the wieght and performance qualities that the designer intended. Moreover, there are books available right here on this website, which provide detailed instructions on how to use plywood in boatbuilding. If for some reason, ply doesn't blow your skirt up and you wish to blaze a new trail by building a plywood targeted design with some other material, then you take a lot of responsibilty upon yourself where performance, reliabilty, durabilty, and safety are concerned.

In any case, document the build and let us all learn with you!

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Andy Garrett

"When all else fails, follow the instructions." -Dad

I think the big issue (in my mind anyway) is that nearly all of us here are amature builders and shouldn't try to fix what ain't broke...marine ply is tried and true so if that's what the architect called for that's what I'd use. I'd be cautious about building something that doesn't have some kind of stamp of approval on it.

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Bill

I told my wife we needed a three-car garage for my projects...she told me to ask her for permission next time before I buy a house.
http://www.unitybuild.net

i wanted to say thanks for the input. i built boats(fiberglass) for three years and have gutted and rbuilt many boats to what i wanted so im not new to boat building i am new to wood boat building though that being said to ttownshaw if you had read the whole thing that was a curiosity question just trying to see what methods are out there for this type of boat building

If you could find 4x8 sheets of smooth flat fiberglass, I think that would work. You would probably need to build up several thin layers to get the appropriate stiffness. But, then you might have a weight problem.

Bill

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Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

Sorry billydean, didn't mean to come off sounding crass...as always, there are alternatives out there. I'm just cautious about giving advice outside of what the architect detailed in his plans.

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Bill

I told my wife we needed a three-car garage for my projects...she told me to ask her for permission next time before I buy a house.
http://www.unitybuild.net

its alright like i said just trying find out what all methods and atlernatives there are for helpful future info i am in the begining steps of building the flats flyer

I'm curious about aluminum over a mahogany frame. How thick would the sheet aluminum have to be to replace a 1/4" thick section of marine plywood?

It seems as if it could be glued and screwed just like ply, with no need to encapsulate.

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Andy Garrett

"When all else fails, follow the instructions." -Dad

Conversion factors of common boatbuilding materials (Mat/Woven Roving Laminate, Aluminum, Steel and Plywood) can be found in Ken Hankinson's book Fiberglass Boatbuilding for Amateurs. See Figure 8.13, Page 74.

As Bill E has stated, weight is going to be an issue. For equal stiffness, 1/4" plywood converts to a solid .240" CSM/Woven Roving laminate. When comparing plywood's weight (.022 LB.CU.IN.) to a Mat/Woven Roving laminate's weight (.055 LB.CU.IN.) it's clear that weight is going to be a problem. Material and labor cost to build the laminate is another one. Vacum bagging flat fiberglass panels to half of the required thickness and laminating the remaining layers once the panels have been affixed to the boat may be a viable option.

As for skinning with aluminum, weight, cost and sealing the seams are the main issues. Best bet is to look at the aluminum boat plans.

The following spreadsheet screen shot demonstrates the conversion process and estimates final weight on a 145 square foot hull :

I'm sure the engineers out there will point out any glitches in the spreadsheet ...

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Paul Kane
Kane Custom Boats Ltd.
Chelsea, Quebec

Building the Glen-L Hot Rod : http://www.kanecustomboats.com

Glen-L Boat Video Directory : http://www.kanecustomboats.com/pages/vi ... ctory.html

I'm wondering about this too--Can you use marine meranti instead of marine grade plywood? I can get 6mm thickness (which is just about identical to 1/4"). I'll have to check how many layers it is but that's 10 bucks or more cheaper a sheet so it'll shave quite a bit off the price of raw materials.

Paul

You point out exactly my point.

Meranti is marine grade. I'm using it myself right now.

Bill

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Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

^^Yeah I know it is, just not sure if it's as easy to work with as Douglas Fir marine grade plywood and whether or not it's as strong, etc.

mr hotrod thanks for the pages thats is helpful info im going to build the way the plans show but like iu said just looking for extra info