Re: Xyenol
--- In bolger@y..., "Jeff Blunck" <boatbuilding@g...> wrote:
Jeff, I've use quite a bit of Xynole, Vectra, Dynel as well as
various types of fiberglass. Also ran some objective tests on
abrasion of these fabrics.
>
> 1. Xyenol at 4 oz. is about the same thickness as 7 or 9 oz.
fiberglass, just lighter in material weight. Glass being heavier
than Polyester.
It's actually thicker but since it's not smooth like glass, it's hard
to measure the thickness.
>
> 2. Xyenol is very good at abrasion resistance compared to same
thickness of fiberglass. I.E. the 4 oz. Xyenol being better than 7
or 8 oz. fiberglass.
A layer of Xynole is many times more abrasion resistant than 9oz FG.
Based on resistance per unit of thickness, it averaged 2.4 times as
resistant.
>
> 3. Wets out easier because the fibers are looser in weave, still
strong but more open, therefore easier to wet out. Shouldn't float
any worse than the same weight fiberglass. Maybe "shouldn't" is a
key word here, I don't know.
True
>
> 4. Epoxy usage should be the same as for the same thickness of
fiberglass.
No way. Xynole takes quite a bit more resin to fill the weave well
enough for a smooth finish. If weight is not a pressing issue, this
is a positive but I would not use Xynole on a small boat like a canoe
or kayak because it adds too much weight.
>
> 5. Xyenol stretches 17%, glass stretches 3%, RAKA epoxy is also
3%. This is on cloth set in epoxy such as sheathing a hull. Don't
use Xyenol for seams and splices as it will allow a lot of stretch,
breaking the epoxy and failing. Seams with Xynol are only as strong
as the epoxy. Same for trying to get added strength in the sheathing
as some designs expect. One in mind is the Flyaway sold by CSB.
True.
>
> 6. Xeynol is a good abrasion protectant and for impact resistance
since it will stretch. You may get the epoxy to crack at the impact
point but I would assume it'll be much harder to actually punch
through because it will absorb more energy stretching. Maybe
somewhere between glass and kevlar.
True, see 2 above.
>
> 7. Harder to cut than glass but not as hard as kevlar or carbon
fiber. Needs a good sharp sissors.
I cut Xynole with a hot knife (soldering iron witha sharp edge).
Seals the edge and is real easy.
>
> 8. And last, doesn't itch, but will ball up and fuzz if sanding
into the cloth, which one should never do or it losses it's strength.
Basically you just can't sand the stuff. Sanding FG ruins the
strength even more than sanding Xynole.
Both Xynole and Vectra are very abrasion resistant but Xynole wets
out much easier and has higher peel strength. Epoxy doesn't stick to
either Vectra or FG cloth well. The open weave and fuzzy fibers of
Xynole allow resin to penetrate all through the material and give it
high peel strength.
--- In bolger@y..., "Jeff Blunck" <boatbuilding@g...> wrote:
Bruce
> I called Larry at RAKA and discussed the Xyenol.Isn't it "Xynole"?
Bruce
THis prety much confirms my views on this
1. Xyenol at 4 oz. is about the same thickness
as 7 or 9 oz. fiberglass, just lighter in material
weight. Glass being heavier than Polyester.<BR>
This is where the float thing comes from if it weighs
half what glass does, then it is going to float. I
accepth both the opinions of those who say this is and
isn't a problem, presumably it is and isn't depending
on use.
<BR>
2. Xyenol is very good at abrasion resistance
compared to same thickness of fiberglass. I.E.
the 4 oz. Xyenol being better than 7 or 8 oz.
fiberglass.<BR>
This agrees with what I have heard also. If I build a
boat I expect to be rubbed to death, perhaps constant
beaching etc... I might go with this stuff. Or go
with it over glass. For me (everyone else can make up
their own mind) I am more interested in adding good
structural factors. Ruel Parkers' boats are heavily
built, for instance, lots of layers of ply, and good
conventional detailing. If he wants to sheath with
something that is mostly abrasion resistant, that may
make sense. The same can hardly be said for many of
Bolger's boats. He is often pushing plywood prety
hard, both in terms of strength and ballast.
<BR>
3. Wets out easier because the fibers are looser
in weave, still strong but more open, therefore easier
to wet out. Shouldn't float any worse than the
same weight fiberglass. Maybe
Which is it, is it more or less dense?
"shouldn't" is a key word here, I don't
know.<BR>
<BR>
4. Epoxy usage should be the same as for the
same thickness of fiberglass.<BR>
Well not if it is more open
<BR>
5. Xyenol stretches 17%, glass stretches 3%,
RAKA epoxy is also 3%. This is on cloth set in
epoxy such as sheathing a hull. Don't use Xyenol
for seams and splices as it will allow a lot of
stretch, breaking the epoxy and failing. Seams
with Xynol are only as strong as the epoxy. Same
for trying to get added strength in the sheathing as
some designs expect. One in mind is the Flyaway
sold by CSB.<BR>
This is the area that bothers me. The gougeons for
instance will say that in certain cases the main
reason they are glassing is just to get a certain
thickness of vapour barrier. Obviously some boats
might be sheathed just to get a certain amount of
abrasion, as with the Parker example. If any of your
reasons are structural, then you will get about the
same result using xynol as you would using rubber
rebar in ferro cement.
<BR>
6. Xeynol is a good abrasion protectant and for
impact resistance since it will stretch. You may
get the epoxy to crack at the impact point but I would
assume it'll be much harder to actually punch through
because it will absorb more energy stretching.
Maybe somewhere between glass and kevlar.<BR>
<BR>
This I think is wrong. Load distribution does not
come from the fiber stretching. The bungy effect is
only helpful if it kicks in at the exact same load
that is being applied. If the xynol's spring starts
to kick in at the point that the epoxy has cracked, or
the rock is through the hull, it isn't very effective,
like a bullet proof vest that stops the bullet after
it passes through the body.
Some tests were published in wooden boat issue 17,
which compared Dynel, and other fabrics. Dynel had
terrible impact performance relative to glass. They
have some convoluted explanation for this that actualy
is based on the inability of the fabric to stretch,
given the fact that it has very high adhesion, and
can't shift in the resin, and point loads extremely.
Another reason has to do with the fact that the weave
is open, there are points where there are a lot of
fibers, and others where there aren't. They also
mention it swelling up badly and requiring twice the
volume of resin of equal dry size glass.
They have a number of nice things to say about dynel
particularly relative to its application. As you
might imagine the epoxy penetrates very well in the
areas where it isn't. They have recently published an
article entirely on xynel, which if I could find my
copy, I would report on it. I don't doubt there are
good things about dynel xynel, but not all things are
good, and structural is not one of them.
7. Harder to cut than glass but not as hard as
kevlar or carbon fiber. Needs a good sharp
sissors.<BR>
<BR>
8. And last, doesn't itch, but will ball up and
fuzz if sanding into the cloth, which one should never
do or it losses it's strength.<BR>
Ditto with glass, if you itch, think how the glass
cloth feels about being sanded through.
<
______________________________________________________________________
Find, Connect Date!http://personals.yahoo.ca
1. Xyenol at 4 oz. is about the same thickness
as 7 or 9 oz. fiberglass, just lighter in material
weight. Glass being heavier than Polyester.<BR>
This is where the float thing comes from if it weighs
half what glass does, then it is going to float. I
accepth both the opinions of those who say this is and
isn't a problem, presumably it is and isn't depending
on use.
<BR>
2. Xyenol is very good at abrasion resistance
compared to same thickness of fiberglass. I.E.
the 4 oz. Xyenol being better than 7 or 8 oz.
fiberglass.<BR>
This agrees with what I have heard also. If I build a
boat I expect to be rubbed to death, perhaps constant
beaching etc... I might go with this stuff. Or go
with it over glass. For me (everyone else can make up
their own mind) I am more interested in adding good
structural factors. Ruel Parkers' boats are heavily
built, for instance, lots of layers of ply, and good
conventional detailing. If he wants to sheath with
something that is mostly abrasion resistant, that may
make sense. The same can hardly be said for many of
Bolger's boats. He is often pushing plywood prety
hard, both in terms of strength and ballast.
<BR>
3. Wets out easier because the fibers are looser
in weave, still strong but more open, therefore easier
to wet out. Shouldn't float any worse than the
same weight fiberglass. Maybe
Which is it, is it more or less dense?
"shouldn't" is a key word here, I don't
know.<BR>
<BR>
4. Epoxy usage should be the same as for the
same thickness of fiberglass.<BR>
Well not if it is more open
<BR>
5. Xyenol stretches 17%, glass stretches 3%,
RAKA epoxy is also 3%. This is on cloth set in
epoxy such as sheathing a hull. Don't use Xyenol
for seams and splices as it will allow a lot of
stretch, breaking the epoxy and failing. Seams
with Xynol are only as strong as the epoxy. Same
for trying to get added strength in the sheathing as
some designs expect. One in mind is the Flyaway
sold by CSB.<BR>
This is the area that bothers me. The gougeons for
instance will say that in certain cases the main
reason they are glassing is just to get a certain
thickness of vapour barrier. Obviously some boats
might be sheathed just to get a certain amount of
abrasion, as with the Parker example. If any of your
reasons are structural, then you will get about the
same result using xynol as you would using rubber
rebar in ferro cement.
<BR>
6. Xeynol is a good abrasion protectant and for
impact resistance since it will stretch. You may
get the epoxy to crack at the impact point but I would
assume it'll be much harder to actually punch through
because it will absorb more energy stretching.
Maybe somewhere between glass and kevlar.<BR>
<BR>
This I think is wrong. Load distribution does not
come from the fiber stretching. The bungy effect is
only helpful if it kicks in at the exact same load
that is being applied. If the xynol's spring starts
to kick in at the point that the epoxy has cracked, or
the rock is through the hull, it isn't very effective,
like a bullet proof vest that stops the bullet after
it passes through the body.
Some tests were published in wooden boat issue 17,
which compared Dynel, and other fabrics. Dynel had
terrible impact performance relative to glass. They
have some convoluted explanation for this that actualy
is based on the inability of the fabric to stretch,
given the fact that it has very high adhesion, and
can't shift in the resin, and point loads extremely.
Another reason has to do with the fact that the weave
is open, there are points where there are a lot of
fibers, and others where there aren't. They also
mention it swelling up badly and requiring twice the
volume of resin of equal dry size glass.
They have a number of nice things to say about dynel
particularly relative to its application. As you
might imagine the epoxy penetrates very well in the
areas where it isn't. They have recently published an
article entirely on xynel, which if I could find my
copy, I would report on it. I don't doubt there are
good things about dynel xynel, but not all things are
good, and structural is not one of them.
7. Harder to cut than glass but not as hard as
kevlar or carbon fiber. Needs a good sharp
sissors.<BR>
<BR>
8. And last, doesn't itch, but will ball up and
fuzz if sanding into the cloth, which one should never
do or it losses it's strength.<BR>
Ditto with glass, if you itch, think how the glass
cloth feels about being sanded through.
<
______________________________________________________________________
Find, Connect Date!http://personals.yahoo.ca
I called Larry at RAKA and discussed the Xyenol. They have been selling it for about a month now, due to a lot of interest by builders. It was an informative conversation so I thought I would share here:
1. Xyenol at 4 oz. is about the same thickness as 7 or 9 oz. fiberglass, just lighter in material weight. Glass being heavier than Polyester.
2. Xyenol is very good at abrasion resistance compared to same thickness of fiberglass. I.E. the 4 oz. Xyenol being better than 7 or 8 oz. fiberglass.
3. Wets out easier because the fibers are looser in weave, still strong but more open, therefore easier to wet out. Shouldn't float any worse than the same weight fiberglass. Maybe "shouldn't" is a key word here, I don't know.
4. Epoxy usage should be the same as for the same thickness of fiberglass.
5. Xyenol stretches 17%, glass stretches 3%, RAKA epoxy is also 3%. This is on cloth set in epoxy such as sheathing a hull. Don't use Xyenol for seams and splices as it will allow a lot of stretch, breaking the epoxy and failing. Seams with Xynol are only as strong as the epoxy. Same for trying to get added strength in the sheathing as some designs expect. One in mind is the Flyaway sold by CSB.
6. Xeynol is a good abrasion protectant and for impact resistance since it will stretch. You may get the epoxy to crack at the impact point but I would assume it'll be much harder to actually punch through because it will absorb more energy stretching. Maybe somewhere between glass and kevlar.
7. Harder to cut than glass but not as hard as kevlar or carbon fiber. Needs a good sharp sissors.
8. And last, doesn't itch, but will ball up and fuzz if sanding into the cloth, which one should never do or it losses it's strength.
Hope this helps some.
Jeff
[Non-text portions of this message have been removed]
1. Xyenol at 4 oz. is about the same thickness as 7 or 9 oz. fiberglass, just lighter in material weight. Glass being heavier than Polyester.
2. Xyenol is very good at abrasion resistance compared to same thickness of fiberglass. I.E. the 4 oz. Xyenol being better than 7 or 8 oz. fiberglass.
3. Wets out easier because the fibers are looser in weave, still strong but more open, therefore easier to wet out. Shouldn't float any worse than the same weight fiberglass. Maybe "shouldn't" is a key word here, I don't know.
4. Epoxy usage should be the same as for the same thickness of fiberglass.
5. Xyenol stretches 17%, glass stretches 3%, RAKA epoxy is also 3%. This is on cloth set in epoxy such as sheathing a hull. Don't use Xyenol for seams and splices as it will allow a lot of stretch, breaking the epoxy and failing. Seams with Xynol are only as strong as the epoxy. Same for trying to get added strength in the sheathing as some designs expect. One in mind is the Flyaway sold by CSB.
6. Xeynol is a good abrasion protectant and for impact resistance since it will stretch. You may get the epoxy to crack at the impact point but I would assume it'll be much harder to actually punch through because it will absorb more energy stretching. Maybe somewhere between glass and kevlar.
7. Harder to cut than glass but not as hard as kevlar or carbon fiber. Needs a good sharp sissors.
8. And last, doesn't itch, but will ball up and fuzz if sanding into the cloth, which one should never do or it losses it's strength.
Hope this helps some.
Jeff
[Non-text portions of this message have been removed]