Geodesic Airolite Boat with a twist
 

I'm looking at building a Geodesic Airolite Boat, (see www.gaboats.com
by Platt Monfort) but I'm considering an interesting idea and I'm
wondering what you all might think. Instead of using wood strips to
form the geodesic structure I am thinking about using foam strips
wrapped in Kevlar tape and epoxy.

I have been reading about the construction of these boats and found
that some people have trouble with bending the ribs to shape without
breaking, (and this is with better quality wood that I am able to
source). I'm thinking I can bend foam cores easily to shape and then
once assembled in a frame start wrapping it all in Kevlar tape,
forming a makeshift Kevlar tube frame.

I'm still considering using wood for the stringers and gunwales as I
can form those with little or no problem. Having the stringers and
gunwales constructed out of wood would also make forming the foam ribs
much easier as it would give me something solid to work the foam
inside.

-Does anyone foresee a problem with pursuing this type of
construction?
-How will Kevlar wrapped foam compare to the equivalent
cross-sectional wood piece in strength?

Thanks
Jordan Richardson

Geodesic Airolite Boat with a twist
 

On 30 Apr 2004 04:22:27 -0700, (Snowman)
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Fascinating! I thought of this idea years ago...and as usual did stuff
all about it!

But my idea relied on triangulation. Was that not the geodesic idea?

Other than that, talk to the designers.

BUT, UNABLE TO SHUT HIS FINGERS UP, HE OPINED:

damn!

Has anyone noticed that although the "a" is nowhere the "e" on the
keyboard, "then" frequently becomes "than"? I have seen it in several
posts. it's NOT just me!

OK.

TMM, rather than wrapping, you need to create a mould for the boat,
then use formers (of foam etc) in place of the wood frames, and not
build "tubes" but glass the frames in place. This is not a new idea.
The filler of frames and even skin separators in lightweight boats has
included foam, balsa, paper rolled up, wood, etc etc.

I am not sure what you mean about "foam strips wrapped in Kevlar tape
and epoxy".

If you mean wrap dry and then place and then wet in, you will have
problems wetting the concealed part of the tubes at the skin side. not
good.

The usual method is to lay up the outside skin, then lay the various
frames (of some really flexible material, like rolled paper, foam,
checked balsa etc) , then lay glass (tape or more skin) over those to
provide the stiffening. The idea is to simply use the _glass_ as the
stiffening beams, with the fillers as a method of shaping the glass.

Look at a modern shed. Most of it is very thin steel, laid out to be
stiff and light. Replace the steel with glass/resin (hard and dense)
and the air in the beans with some crap lightweight filler to hold the
glass inplace until the filler will.


But this relies heavily on the fact that the beams are flanged and
strongly attached to the main skin.

I'm looking at building a Geodesic Airolite Boat, (see www.gaboats.com
by Platt Monfort) but I'm considering an interesting idea and I'm
wondering what you all might think. Instead of using wood strips to
form the geodesic structure I am thinking about using foam strips
wrapped in Kevlar tape and epoxy.

I have been reading about the construction of these boats and found
that some people have trouble with bending the ribs to shape without
breaking, (and this is with better quality wood that I am able to
source). I'm thinking I can bend foam cores easily to shape and then
once assembled in a frame start wrapping it all in Kevlar tape,
forming a makeshift Kevlar tube frame.

I'm still considering using wood for the stringers and gunwales as I
can form those with little or no problem. Having the stringers and
gunwales constructed out of wood would also make forming the foam ribs
much easier as it would give me something solid to work the foam
inside.

-Does anyone foresee a problem with pursuing this type of
construction?
-How will Kevlar wrapped foam compare to the equivalent
cross-sectional wood piece in strength?

Thanks
Jordan Richardson

************************************************** **
The Met Bureau is LOVE!

Geodesic Airolite Boat with a twist
 

"Snowman" wrote in message
om...
I'm looking at building a Geodesic Airolite Boat, (see www.gaboats.com
by Platt Monfort) but I'm considering an interesting idea and I'm
wondering what you all might think. Instead of using wood strips to
form the geodesic structure I am thinking about using foam strips
wrapped in Kevlar tape and epoxy.

I have been reading about the construction of these boats and found
that some people have trouble with bending the ribs to shape without
breaking, (and this is with better quality wood that I am able to
source). I'm thinking I can bend foam cores easily to shape and then
once assembled in a frame start wrapping it all in Kevlar tape,
forming a makeshift Kevlar tube frame.

-Does anyone foresee a problem with pursuing this type of
construction?
-How will Kevlar wrapped foam compare to the equivalent
cross-sectional wood piece in strength?

Potential problems: The foam is not as stiff as the wood, so you may
need to shorten the spacing between molds in order for them to lie
fair. I think laying up glass tube is not as easy as it sounds, but
a dedicated person can make it happen. I see it as being really hard
to keep the foam tubes fair during the layup process. I think
construction will go much faster with wood, as long as you can
find decent stock. Find a wood that bends easily, without a lot
of grain runout..

As far as strength goes, it can be as strong but I don't think it will
be as stiff. Wood is an incredibly stiff material for its weight, so
does a good job keeping the structure rigid. In essence, the GA
boats rely on the skin to keep the water out, and the shape is held
by the wood. If you don't have as stiff an internal structure, the
boat might be a little more bendy than you like. This may or may
not be a good thing - some eskimo kayaks were pretty flexible.
Whether this bothers you or not may be a matter of taste.

Matt

Geodesic Airolite Boat with a twist
 

I'd recommend buying some Kevlar and trying your idea out, with the wood
versions next to it. Kevlar is tough enough to lay on a smooth flat
surface. You may find that it's more hassle than it's worth unless you
vacuum bag it. Try it first. Prove me wrong. Test the results
mechanically ...clamp the samples to a table (your composite and the wood)
and hang weights off the end to find out how much each deflects versus the
other and where the breaking point occurs and how it breaks. Most of all,
have fun.

Brian

--
http://www.advantagecomposites.com/tongass -- My 22' Tolman Skiff project
http://www.advantagecomposites.com/catalog -- Discounted System Three
Resins products


..
"Snowman" wrote in message
om...
I'm looking at building a Geodesic Airolite Boat, (see www.gaboats.com
by Platt Monfort) but I'm considering an interesting idea and I'm
wondering what you all might think. Instead of using wood strips to
form the geodesic structure I am thinking about using foam strips
wrapped in Kevlar tape and epoxy.

I have been reading about the construction of these boats and found
that some people have trouble with bending the ribs to shape without
breaking, (and this is with better quality wood that I am able to
source). I'm thinking I can bend foam cores easily to shape and then
once assembled in a frame start wrapping it all in Kevlar tape,
forming a makeshift Kevlar tube frame.

I'm still considering using wood for the stringers and gunwales as I
can form those with little or no problem. Having the stringers and
gunwales constructed out of wood would also make forming the foam ribs
much easier as it would give me something solid to work the foam
inside.

-Does anyone foresee a problem with pursuing this type of
construction?
-How will Kevlar wrapped foam compare to the equivalent
cross-sectional wood piece in strength?

Thanks
Jordan Richardson

Geodesic Airolite Boat with a twist
 

If you have not built one of these boats before I'd recommend watching the
video. I've not built one but have watched the video fo which the Ottawa
library has a copy. TF Jones, who has built one, said he had to watch the
video to see how it was done. It's normal to break a few ribs when stema
bending them into a hull. The video shows how to do it.

For foam ribs it might be better to form them over the outside of the hull
and then press them into the interior and trim the ends. To do this the
foam would have to be pretty thin. I think you'll end up adding weight to
the boat.

Other variations have been tried on these boats, eg using plastic
stringers instead of wood and using polyester cord instead of kevlar (both
are used in car tires, mostly polyester). I imagined fitting thin foam
strips between the stringers to provide some backing to prefvent
punctures, give the hull stiffness, and eliminate the condensation on the
inside of the hull.

--
------------------------------------------------------------------------------
William R Watt National Capital FreeNet Ottawa's free community network
homepage: www.ncf.ca/~ag384/top.htm
warning: non-freenet email must have "notspam" in subject or it's returned

Geodesic Airolite Boat with a twist
 

Kevlar floats on top of resin. So it has to be vacuum bagged. One issue
I could see is if you were trying wrap the strip completely in kevlar.
Not sure how well it would bend around a 90 degree edge. And that's 90
degrees F or C. (a little early morning humor... ;p )


--
Matt Langenfeld
JEM Watercraft
http://jem.e-boat.net/


Brian D wrote:
I'd recommend buying some Kevlar and trying your idea out, with the wood
versions next to it. Kevlar is tough enough to lay on a smooth flat
surface. You may find that it's more hassle than it's worth unless you
vacuum bag it. Try it first. Prove me wrong. Test the results
mechanically ...clamp the samples to a table (your composite and the wood)
and hang weights off the end to find out how much each deflects versus the
other and where the breaking point occurs and how it breaks. Most of all,
have fun.

Brian

Geodesic Airolite Boat with a twist
 

On 30 Apr 2004 04:22:27 -0700, (Snowman)
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Maybe I was OOL with my comments.

Are these "ribs" _just_ wood, or are they formers that are then
glassed in?

If they are just ribs then wood in the way to go...learn how to bend
wood.

If they are later glassed in, then the mech, properties of the ribs
become far less important. Compressibility (pinching) becomes more
important than stiffness. The best solution would be kerfed wood;
easily bent, hard to compress/pinch.


I _still_ don't see how these fit the "geodesic" mould.

Remember that with lightweight craft, skin penetration can become a
problem. from my kayaking experience, the boat will hole well before
it folds. Kayaks are very strong, because their cigar shape makes then
that way. Building a boat with a super-thin skin, stiffened by
stringers, will aid this. I suppose kevlar etc will go a long way down
that path.

I would prefer to go on a high protein diet and add a couple of kilo
to the boat!


I'm looking at building a Geodesic Airolite Boat, (see www.gaboats.com
by Platt Monfort) but I'm considering an interesting idea and I'm
wondering what you all might think. Instead of using wood strips to
form the geodesic structure I am thinking about using foam strips
wrapped in Kevlar tape and epoxy.

I have been reading about the construction of these boats and found
that some people have trouble with bending the ribs to shape without
breaking, (and this is with better quality wood that I am able to
source). I'm thinking I can bend foam cores easily to shape and then
once assembled in a frame start wrapping it all in Kevlar tape,
forming a makeshift Kevlar tube frame.

I'm still considering using wood for the stringers and gunwales as I
can form those with little or no problem. Having the stringers and
gunwales constructed out of wood would also make forming the foam ribs
much easier as it would give me something solid to work the foam
inside.

-Does anyone foresee a problem with pursuing this type of
construction?
-How will Kevlar wrapped foam compare to the equivalent
cross-sectional wood piece in strength?

Thanks
Jordan Richardson

************************************************** **
The Met Bureau is LOVE!

Geodesic Airolite Boat with a twist
 

Old Nick says:

Are these "ribs" _just_ wood, or are they formers that are then
glassed in?

Nick, I would HEARTILY recommend you check out the geodesic boat site at
www.gaboats.com
before you get past your ankle there ;-)
It certainly sounds as though you haven't "got" the concept. Not 'ffense, or
anything, just an observation.

Steve

Geodesic Airolite Boat with a twist
 

My only concern would be keeping constant the frame material.
Especially if you are laying this stuff up by hand. If you want to use
Kevlar for a Kayak, use it for the skin, laid over fiberglass etc, not
for the frame, only my opinion. Scotty from Sm... oh, I just can't do
it, not for a nothing answer...

Geodesic Airolite Boat with a twist
 

On 01 May 2004 21:26:39 GMT, ospam (Stephen Baker)
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Old Nick says:

Are these "ribs" _just_ wood, or are they formers that are then
glassed in?

Nick, I would HEARTILY recommend you check out the geodesic boat site at
www.gaboats.com

before you get past your ankle there ;-)
Sorry. Don't get ya.

It certainly sounds as though you haven't "got" the concept. Not 'ffense, or
anything, just an observation.

Yeah I had looked but did not pick up on the diagonals. I also did not
pick up that it's not glassed, but shrink-wrapped...hhhmmmm... ok.
************************************************** **
The Met Bureau is LOVE!