Hi All -

I occasionally come across the phrase "lay-up" when I read about
kayak construction - usually having to do with fiberglass boats.

Typically it is in the context of problems having to do with a
particular boat's "lay-up".

Could someone please define that term for me?
And what are the usual problems associated with it?

Thanks,
TwoK

(two_k2003) wrote in news:836efb4c.0312090713.5304ef51
@posting.google.com:

Hi All -

I occasionally come across the phrase "lay-up" when I read about
kayak construction - usually having to do with fiberglass boats.

Typically it is in the context of problems having to do with a
particular boat's "lay-up".

Could someone please define that term for me?
And what are the usual problems associated with it?

"Lay-up" refers to how the boat is constructed and typically describes the
materials used on a composite boat (fiberglass, kevlar, carbon fiber, etc)
but it's also used to differentiate a composite boat from a plastic boat.

Specifically it might refer to the type of cloth used, the "weight" of the
cloth, and how many layers are used (and where they're placed).

Often you'll see the term to describe different versions of the same model.
For example, a boat may be available in a "racing layup" (very light),
"standard layup" (medium weight), or "expedition layup". An boat with an
expedition layup might use heavier weight cloth and have reinforcements
along the keel line, possibly with a different material (i.e. Diolen).

As far as problem associated with a particular layup, boats with a heavy
layup are just that; heavy, but possibly more durable. A boat with a light
layup would be easy to carry but might need ot be treated with "kids
gloves" to avoid damage to the hull. A kevlar layup might produce a boat
that is light *and* durable, but also more expensive.

"two_k2003" wrote in message
om...
Hi All -

I occasionally come across the phrase "lay-up" when I read about
kayak construction - usually having to do with fiberglass boats.

Typically it is in the context of problems having to do with a
particular boat's "lay-up".

Could someone please define that term for me?
And what are the usual problems associated with it?

Thanks,
TwoK

Lay-up refers to the actual physical process of hand "laying" the layers of
reinforcing material into or onto a mold used in the construction of
composite (fiberglass, kevlar) products. It is a term used almost
universally by people that make all types of composite products by means of
hand laying the matt or woven cloth in place. Another method of
construction is referred to as a "spray-up". That's when small strands or
pieces of the reinforcing material are blown or sprayed into a mold rather
than laid in by hand in sheets of matt or woven cloth form.

Problems with lay-up can range from negative characteristics such as
extremes (one way or another) in weight to inconsistency from one part
sample to another to faulty construction such as too much cloth and not
enough of the resin or epoxy that binds it all together or vice-versa.

The layer that makes all of this yucky stuff look nice and resist damage is
called the gel coat. Sometimes the gel coat, which also gives the finished
part its color, can have pin holes or bubbles or tiny patterns of cracks
called crazing. Defects in the lay-up are often also referred to as
problems with the lay-up.

I hope this information is helpful to your understanding. I'm getting a
headache and itchy all over just thinking about it!

DV

"Dave Van" wrote


Defects in the lay-up are
often also referred to as
problems with the lay-up.


What I meant to write in the above sentence is: Defects in the GEL COAT are
often also referred to as problems with the lay-up.

Cheers

DV

The term "layup" is not necessarily indicative of hand layups. The term
is also used to describe composite structures that are vacuum bagged. As
John stated, it's a generic term used to describe the characteristics
of a composite.

From: Brian Nystrom
Organization: AT&T Worldnet
Newsgroups: rec.boats.paddle.touring
Date: Wed, 10 Dec 2003 12:13:32 GMT
Subject: What is "Lay-Up?"

The term "layup" is not necessarily indicative of hand layups. The term
is also used to describe composite structures that are vacuum bagged. As
John stated, it's a generic term used to describe the characteristics
of a composite.



I was also trying to shed some light on the historical origins of the use of
the word. And, buy the way, on parts that are vacuum bagged, the cloth did
not magically appear. It was placed there somehow. Most often, Laid there
by hand. Even the most precisely engineered composite parts such as those
used on aircraft components and race car bodies are laid up by hand before
going into the autoclave.