Thats what I found, the time to make and research and perfect a method
using foam, the loss and cost of material from having a few failures, it was
quicker and cheaper I concluded to do things the old fashioned way, I also
at that time did not have a reliable source of foam, I found if I lied, the
cost of foam dropped by half, ( told them I was a builder and wanted the
foam to insulate a hot water heater ). I could have built the deck much
lighter but I used 5/8 spruce longerons, when 3/8 would be good enough, but
its just to much hassle cutting up the wood, or sourcing it locally, and the
two front frames are quite heavy spruce, to act as a roll over cage, when a
laminated frame would be stronger and lighter.
I wanted to use 2,5 millimeter GL2 birch 5 ply, but its too much
headache getting the stuff here, I tried soaking some of this material in
water, and after a few hours it bent very easily, and would have made a very
very strong skin, not sure what the soaking would have done to its
engineering properties, but it seemed to dry out with no ill effects,
eventually settled on 2 millimeter 3 ply hoop pine available locally for
about $60 for a 8ft x 4ft sheet. Not the optimum choice strength wise, but
it is a certified engineering material, and it seems to do the job ok.
Chris Johnston
North Richmond
Australia..
----- Original Message -----
From: "Donald Reid" <donr...@peoplepc.com>
To: "KRnet" <kr...@mylist.net>
Sent: Friday, June 30, 2006 7:52 AM
Subject: Re: KR> Turtle deck
> At 09:13 AM 6/29/2006, you wrote:
>> I have just finished the basic structure for the turtle deck
>> from wood, it seems pretty strong, I can almost stand on it but am
>> not game to try, it weighs about 4 lbs, with the ply skin still to
>> be fitted, the sheet of ply for the skin weighs 5 lbs and I will
>> use about 2/3 of the sheet, so all up the turtle deck from wood
>> will weigh about 7 lbs, my question is, how does this compare
>> weight wise to a composite structure?
>
> I made a female mold and did a layup with three plies of light weight
> glass with foam and glass "ribs" at each bay location. It probably
> weighed a little less but it was significantly more work.
>
>
>
> Don Reid - donreid "at" peoplepc.com
> Bumpass, Va
>
> Visit my web sites at:
>
> AeroFoil, a 2-D Airfoil Design And Analysis Computer Program:
> http://aerofoilengineering.com
>
> KR2XL construction: http://aerofoilengineering.com/KR/KR2XL.htm
> Aviation Surplus: http://aerofoilengineering.com/PartsListing/Airparts.htm
> EAA Chapter 231: http://eaa231.org
> Ultralights: http://usua250.org
> VA EAA Regional Fly-in: http://vaeaa.org
>
>
>
>
> _______________________________________
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