WW_Canoe hull materials......
 

Hi fellow paddlers...
Hey after a few years of lean employment...I'm going to get back into
canoeing.
Am looking to get into the WW side, can handle any hull in any type of
FLA****er, but the WW pull is strong;-)(excuse the very small pun).
I know plastic(in its many forms) is terrific....but would like to
know if anyone has paddled any flavor of kevlar...or any other light &
stiff material lately...

thanks....
Steve

Generally not recommended. Plastic (in one of it's many forms) is
really best for whitewater for a couple of reasons:

Plastic can scrape and bang along the rocks in the river and not get
hurt. I'd hate to drag a nice kevlar boat over rocks.

Plastic can bend quite a bit, but still has "memory", and will pop back
to original condition. Kevlar/fibreglass will bend to the point of
cracking, and then you're looking at a repair job (if it's salvagable).

M

On 18 Aug 2004 19:03:51 -0700, Steve ] wrote:
WW_Canoe hull materials......
| Hi fellow paddlers...
| Hey after a few years of lean employment...I'm going to get back into
| canoeing.
| Am looking to get into the WW side, can handle any hull in any type of
| FLA****er, but the WW pull is strong;-)(excuse the very small pun).
| I know plastic(in its many forms) is terrific....but would like to
| know if anyone has paddled any flavor of kevlar...or any other light &
| stiff material lately...
|
| thanks....
| Steve


--
Max Stevens

I'll use a Kevlar boat up to class III, but for rockbashing or bigger
water Royalex is really a better choice.

The weights on a Kevlar whitewater boat aren't that much better than
Royalex (I paddle a We-no-nah Rendezvous Kevlar, not quite a
whitewater but good to III). Western Canoeing has the Probe and Viper
in Kevlar running 44lbs or so, my Royalex Ocoee is 42 lbs.

The only problems I have had with composite boats are rock gardens in
low water. Go over a small drop, smack the stern, hit another rock and
smack the side. After a few trips, it's time for some gel repair.

Performance wise the composites totally outperform Royalex in calmer
water. In class III+ and big stuff, you don't want a fast hull. The
water is moving too fast already, and you want something that won't
punch right into the waves. Slower hulls are better, and Royalex is
the best material for it.

If you are planning on staying class I-II, go Kevlar. If you plan to
enter the III range, the Royalex will be cheaper, more durable, and
just as light.

Remember some of the words you used to describe Kevlar were "stiff"
and "light". Smack a rock, and "stiff" shears. Floppy bends, absorbs,
and survives. "Light" really isn't light if built for durability (see
weights above).

I have wrapped both materials. Both hate it, no matter what a plastic
boater says, Royalex is not a happy camper when the bow hits the
stern. The Kevlar cracked along the side, but otherwise held it's
shape very well. In fact without any repair we paddled a tacoed Kevlar
Encounter 9 miles out to the truck. It took an hour to patch it, and
the patch looks like the boat was wrapped, but otherwise it's
structurally fine. Wrapped boats generally need new gunwales, and that
price is constant.

Both materials don't like to be scraped over rocks. You can spray more
vinyl on the skin of a Royalex boat to fill in the scratches. You can
re-gel a composite. I've found that painting the bottom of my
composite boats with a mixture of epoxy, graphite, and silica makes a
super tough bottom. The graphite lubricates the rock and what would be
a long scratch turns into a three inch wonder.

Royalex whitewater boats are easily obtained. Composite is a special
order, or rare find. For getting started in whitewater, buy the
cheapest thing you can, because you will destroy it learning how to
paddle it. Once you have some skills, look into a new boat. Until then
I'd buy something cheap, and that's most likely to be plastic.

An excellent reply. I would only add that the only time the weight
difference is a factor is when you are carrying it. In the water the
difference is insignificant as a solo boat will only account for 25% or less
of the total weight. The difference between the lightest Kevlar and heaviest
royalex reduces this to less than 10%. Put differently, the 20 or so pound
difference displaces about 1/3 of a cubic foot of water evenly distributed
across the entire footprint of the boat. So, (and I haven't calculated it),
your boat might be 1/50th of an inch deeper in the water. I use royalex on
all rocky rivers. If there aren't rocks, you could paddle a paper boat.
____________________________
Sincerely,
Carey Robson -- www.CanoeBC.ca

"Eric Nyre" wrote in message
om...
I'll use a Kevlar boat up to class III, but for rockbashing or bigger
water Royalex is really a better choice.

The weights on a Kevlar whitewater boat aren't that much better than
Royalex (I paddle a We-no-nah Rendezvous Kevlar, not quite a
whitewater but good to III). Western Canoeing has the Probe and Viper
in Kevlar running 44lbs or so, my Royalex Ocoee is 42 lbs.

The only problems I have had with composite boats are rock gardens in
low water. Go over a small drop, smack the stern, hit another rock and
smack the side. After a few trips, it's time for some gel repair.

Performance wise the composites totally outperform Royalex in calmer
water. In class III+ and big stuff, you don't want a fast hull. The
water is moving too fast already, and you want something that won't
punch right into the waves. Slower hulls are better, and Royalex is
the best material for it.

If you are planning on staying class I-II, go Kevlar. If you plan to
enter the III range, the Royalex will be cheaper, more durable, and
just as light.

Remember some of the words you used to describe Kevlar were "stiff"
and "light". Smack a rock, and "stiff" shears. Floppy bends, absorbs,
and survives. "Light" really isn't light if built for durability (see
weights above).

I have wrapped both materials. Both hate it, no matter what a plastic
boater says, Royalex is not a happy camper when the bow hits the
stern. The Kevlar cracked along the side, but otherwise held it's
shape very well. In fact without any repair we paddled a tacoed Kevlar
Encounter 9 miles out to the truck. It took an hour to patch it, and
the patch looks like the boat was wrapped, but otherwise it's
structurally fine. Wrapped boats generally need new gunwales, and that
price is constant.

Both materials don't like to be scraped over rocks. You can spray more
vinyl on the skin of a Royalex boat to fill in the scratches. You can
re-gel a composite. I've found that painting the bottom of my
composite boats with a mixture of epoxy, graphite, and silica makes a
super tough bottom. The graphite lubricates the rock and what would be
a long scratch turns into a three inch wonder.

Royalex whitewater boats are easily obtained. Composite is a special
order, or rare find. For getting started in whitewater, buy the
cheapest thing you can, because you will destroy it learning how to
paddle it. Once you have some skills, look into a new boat. Until then
I'd buy something cheap, and that's most likely to be plastic.

On 26-Aug-2004, (Eric Nyre) wrote:

Remember some of the words you used to describe Kevlar were "stiff"
and "light". Smack a rock, and "stiff" shears. Floppy bends, absorbs,
and survives. "Light" really isn't light if built for durability (see
weights above).

Light also means that it will transfer more of the force in bending the
hull to the gunwale. I've seen an ash gunwale snap in easy WW. The
Kevlar canoe was empty but for two paddlers and when they pounded over
a small haystack, the gunwale went into compression and popped.
I'd guess that a vinyl gunwale would have handled it; aluminum, maybe.
The problem is that the only way out for the gunwale is to buckle and
that may permanently deform the aluminum gunwale (unless, of course
it manages the load without buckling).

I certainly wouldn't recommend an ultralight Kevlar canoe in WW. The
hulls of those are too flimsy to take the pounding of a few haystacks.

The problem with the word "light" is that it doesn't quantify anything.
One light canoe might handle it, another not.

Mike

Michael Daly wrote:

Light also means that it will transfer more of the force in bending the
hull to the gunwale. I've seen an ash gunwale snap in easy WW. The
Kevlar canoe was empty but for two paddlers and when they pounded over
a small haystack, the gunwale went into compression and popped.
I'd guess that a vinyl gunwale would have handled it; aluminum, maybe.
The problem is that the only way out for the gunwale is to buckle and
that may permanently deform the aluminum gunwale (unless, of course
it manages the load without buckling).

I certainly wouldn't recommend an ultralight Kevlar canoe in WW. The
hulls of those are too flimsy to take the pounding of a few haystacks.

The problem with the word "light" is that it doesn't quantify anything.
One light canoe might handle it, another not.

Mike

That gunwale failure wasn't due to the hull design - it was a bad
gunwale. I've paddled quite a lot of "heavy water" class 3 in my 23 lb
kevlar boat with no problems. It's all how you do it. Because the boat
is so light, I rarely hit rocks anyway.

The good part is that (contradicting a previous post) you can definitely
feel the difference between a 25 lb. boat and a 40 lb boat. It's not
the total weight - it's the polar moment of inertia that you can feel.
And that's roughtly proportional to the boat's weight - since the
paddler is in the center of the boat, (s)he adds little to the total.

For the gunwale comment:

I've seen ultra-light boats without enough thwarts to handle any type
of wave. I typically add one or two thwarts to my whitewater boats, to
stiffen the sides and reinforce them. I do that mostly on Royalex but
would probably do the same on composite. If the gunwales are not
properly supported, they will flex to no end and pop goes the weasel.

For the weight comment:

Yep, weight makes a big difference. If you are seriously looking for
performance then go Kevlar, drop the weight, and accept the fact you
may have to buy a new boat sooner than expected. I notice even a 5lb
difference in hulls, and dropping the weight even more can make a
difference. That said, losing 5lbs of fat from my belly does almost
the same thing. It's inertia, and the lighter the boat (lighter total
load) the faster it will respond. You can take two identicle hulls,
one out of graphite, the other heavy fiberglass and with the 30lb
difference it is night and day. The heavier boat does not react nearly
as fast as a light boat. You can definitly feel it. The boats may sit
almost as low in the water, that's not the issue. The issue is
acceleration and fast reaction. Heavier boats react much slower than
light boats.

Still, for someone just starting in whitewater, go Royalex. You can
buy the graphite Outrage later when you have the skills to give it
proper respect. The learning curve can be hard on boats, so buying the
cheapest, most durable makes sense. If you develop the skills not to
trash a heavy boat, you will have more than enough skill to keep a
light boat in shape.

I'm thinking of adding an extra thwart to my MR Freedom, I want it to
be a thwart that installs with two screws on each side. I think I am
getting side to side shimmy. A single screw on each side would not do
much to stop that.

Thoughts? Am I full of crap?


-Dan V.

On 28 Aug 2004 19:31:29 -0700, (Eric Nyre)
wrote:

For the gunwale comment:

I've seen ultra-light boats without enough thwarts to handle any type
of wave. I typically add one or two thwarts to my whitewater boats, to
stiffen the sides and reinforce them. I do that mostly on Royalex but
would probably do the same on composite. If the gunwales are not
properly supported, they will flex to no end and pop goes the weasel.

Hi Dan,

I just install them with one bolt on each side. Screws work loose, and
bolts with nylocks don't.

As for side to side shimmy, I haven't had that problem. I put the
thwart in to keep the sides of the boat from flexing too much, but I
want them to be able to flex a little. If there is no movement at all,
and you hit something hard, well... somethings gotta give. I'd rather
have a little flex on that joint, than to have the whole thwart rip
out. Besides, putting one hole in the gunwales is less damaging than
putting two holes close together.

Just my $.02

Dan Valleskey wrote:
I'm thinking of adding an extra thwart to my MR Freedom, I want it to
be a thwart that installs with two screws on each side. I think I am
getting side to side shimmy. A single screw on each side would not do
much to stop that.

Thoughts? Am I full of crap?

Install two light thwarts in an X pattern. Pinning them where they
cross makes things even better. It will keep the sides of the boat from
lozenging while acting as a single regular thwart.