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It had long ago been decided that this hull would be built using
Airex foam.
Later research would convince me that epoxy and knitted glass
would provide a far superior laminate than polyester resin, mat
and woven roving would.
Epoxy, knitted glass and Airex core would provide just about the
best cruising hull on the planet.
It was not an easy sell, but it was the right one for me.
Probably not find another boat built like this in the entire
world.
There is/was no foam on the planet the equal of Airex at that
time. It was also the most expensive. Leave it to the Swiss
top produce the best.
Knitted glass only works with epoxy and produces the highest
glass content, toughest laminate possible for a boat hull
including carbon and Kevlar.
A 50/50 glass/epoxy ratio is quite common, even without vacuum
bagging.
By comparison, a 35/65 glass/resin ratio is about the best you
can hope for if using polyester.
Compared to epoxy, polyester definitely produces an weaker, as
well as heavier, lower cost product.
This hull is also stronger than steel which ultimately will rust
from the inside out.
Steel will probably not stop a copper jacketed .357 Mag slug.
My hull did. Still have the hull section with slugs inside to
prove it.
An Airex cored hull also provides an insulated hull without
added insulation.
Thus the hull is a sandwich core design.
The external skins are epoxy and knitted glass.
The core is 1" thick Airex foam.
The hull lamination schedule is as follows:
INTERIOR SKIN:
There are four (4) layers of 24 Oz, double bias (+/- 45) knitted
glass, forming a 96 Oz laminate.
EXTERIOR SKIN:
There are four (4) layers of 34 Oz, tri-axial knitted glass that
extend from the centerline to the shear.
There are two (2) layers of 24 Oz, double bias (+/- 45) glass
that also extend from the centerline to the shear.
There are two(2) layers of 34 Oz, tri-axial glass that extend
from the centerline to 18" above the waterline.
The above schedule creates a 252 Oz, knitted glass laminate at
the waterline.
KEEL:
There are sixteen (16) layers of 34 Oz, tri-axial glass that
form the sides of the keel. These pieces overlap to form the
bottom of the keel with 32 layers of 34 OZ tri-axial knitted
glass.
KEELSON:
The forward portion of the keelson has 24 layers of 34 Oz,
tri-axial knitted glass while the rear portion of the keelson
has 15 layers of 34 Oz, tri-axial knitted glass.
SKEG:
The skeg has 20 layers of 34 Oz tri-axial knitted glass.
WEAR SHOE:
The bottom of the skeg and the bottom of the keel are covered
with a wear shoe that is approximately 3/4" thick.
This shoe was constructed using 60 grit sand blasting garnet and
epoxy.
BOW THRUSTER TUBE:
The bow thruster tube has been installed and consists of six (6)
layers of 34 Oz tri-axial knitted glass.
Why the above structure.
A sandwich construction provides absolutely the strongest
possible hull.
There is/was no foam on the planet the equal of Airex at that
time.
It provides the highest energy absorbsion of any foam.
During a test, the Airex stopped a copper jacketed 0.357 mag
slug dead from 25 ft away.
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