download - WaveLength Paddling Magazine

Vacuum bagging has the resin added to
a dry laminate, then the bag is added and
the resin is then spread through the laminate
with rubber or hard plastic squeegees.
The glass fabric or cloth to resin ratio is
only slightly higher than the best hand laminate
but the reduction of resin does decrease
the finished product’s weight somewhat.
With vacuum infusion, the dry cloth
laminate is bagged under very high pressure,
normally 14.5 pounds per square inch,
which translates to a ton of force per square
foot. Under this pressure, all moisture and
air is removed from the dry laminate before
the resin is introduced. The vacuum
pressure is then used to draw the liquid resin
through the laminate and is maintained until
the part solidifies.
The result is a finished product that uses
less resin and yields a glass to resin ratio of
70 to 30%. Since there is no excess resin
in the material laminate, we see an increase
in strength and a reduction in overall
weight.
Many paddlers opt for carbon or carbonkevlar
to gain extra strength, and to drop a
few pounds of weight, but that comes with
a price tag that is hard to justify for some of
us. Generally speaking, the cost of these
materials ends up averaging $100 per
pound of weight saved.
With infusion we can gain the strength
and lose some weight without the extra cost
associated with exotic materials like carbon
and kevlar. Because the infusion process
lends itself so well to production manufacturing,
these advantages need not come
at the higher costs attached to these exotic
materials. Ironically, even the exotics like
carbon and kevlar gain from the infusion
process and yield the same advantages enjoyed
by the more conventional materials,
again without adding to the cost.
Although some companies are slow to
embrace these new techniques, it is obvious
that environmental concerns and the
added advantages of closed molding will
set the demand for stronger, lighter and
“greener” kayaks and canoes.
Since paddlers in general are a very environmentally
aware group I’m confident
that we will soon have the choice of our
favorite designs constructed with the latest
technology—if we ask we will receive.
Here’s to “greener” boats. ❏
© Jamer Buote is President of Inukshuk
Adventure Group on Vancouver Island. He has
31 years in the marine manufacturing industry
and 25 years experience in composite
manufacturing. He’s an avid paddler, sailor,
hiker and dog musher.
Modern materials definitely have their their advantages but
our friend Doug has identified at least one potential downside.
“Guess I parked ‘er a little too close to the camp fire.”
December/January 2003 www.WaveLengthMagazine.com
19