"Te Canaille" wrote in message
newsUqoc.144857$f_5.80076@lakeread01...
Riverman :

Thanks for the response and advice. There was some wishful thinking here
for an easy solution and I think you're probably right and
reckon I won't fuss with this.

The thing about shortening the thwarts brings up an interesting point. A
few years back Mohawk Canoes came out with an adjustable
thwart, mainly for whitewater canoes. The paddler could twist it to
shorten or lengthen. I called Daryll and spoke to him about this
and he maintained that shortening the thwart decreased rocker. The canoe
in question already has a flat keel-line. What I would like
to do is add a slight amount of rocker to stop the oil canning and
increase maneuverability and an arched bottom to increase
secondary stability. I wondering about the memory of Royalite. If I strap
( or add a shortened thwart ) the hull amidships to arch
the bottom for several months would it just bouce back to flat or retain
some arch ? My guess is that it would retain some arch for
a while but eventually flatten out. This will be the third canoe I've lost
to oil canning and it'd be great to figure out a
solution.


Its true that shortening the thwarts decreases rocker. If you want to do
both, I did see someone who cut slivers out of the side of the boat,
basically removed a triangle, to create rocker.

He cut two pieces from each side, the base of the triangle on the rail, the
point right down at the chine (even curling just a tiny bit around the
bottom, like a few mm.) The pieces were each about 1/3 the hull length from
the ends, maybe a hint closer to the center. The base of each triangle
removed about 1 inche of rail, but the resulting 'suture' raised the ends
up several inches (you can do the math).

It would be interesting: remove two slivers from each side to OVERcreate
rocker, then shorten the thwarts to round the bottom, and remove some
rocker. You'd have a pretty unique boat when you were done. Personally, I
think I'd work on the hole-in-the-sand method..

--riverman

"Mike McCrea" wrote in message om...
Te,

Re-molding the basic hull shape of a Royalite canoe seems to me an
iffy proposition at best. I don't know anyone who has this as
much deleted

Thanks Mike. I appreciate the feedback. I think I might try the reinforcement approach that you discuss.

Say, didn't I see an article by you in the current "Paddler" about lake paddling ? Nicely done.

Te Canaille

"Bill Tuthill" wrote in message
...
riverman wrote:

Hmm, I don't see an obvious easy solution to this, but what you're
envisioning doesn't look good. I once saw a royalex boat that was too
close
to a campfire reach the temperature where it lost its cohesive
stability.
The hull suddenly had the consistency of freshly cooked lasagna noodles,
and
it was was impossible to hold it in shape with our hands while it cooled
and
got rigid. We flopped it down rightside up on the ground, and to this
day it
still has a completely flat bottom because of that. If it had landed on
a
stick, that would have just gone right through the bottom.

Sounds like Royalex is a tradename for polypropylene. Is it?
Polypropylene has a very low melting temperature, but is otherwise
strong, lightweight and durable.


Royalex is a Uniroyal trade name for a laminate sheet of Crosslink Vinyl
sandwiching ABS sheeting and an ABS (or PVC) foam core.
http://www.easyriderkayaks.com/royalex_canoes.htm
The core itself has little strength, so the next layer of ABS sheeting gives
it backbone, while the vinyl coating provides UV and abrasion protection.
Its when the outer ABS sheet starts to melt that your troubles begin.

Lots of companies use different thinknesses of core, different coverings,
etc, but they are all 'Royalex', and all made by Uniroyal. Some of the
'other' names for Royalex are Royalite and Oltonar. Royalite uses a PVC core
and a thinner layup. Currently, the rights to manufacture Royalite is owned
by Spartech.
www.spartech.com

--riverman

Riverman :

Interesting. Don't reckon I need rocker badly enough to try any carving or maybe I just don't have enough experience to give the
confidence to attempt this. Reckon I'll try some other approaches.

I'll bite, what's the "hole in the sand method" ?





"riverman" wrote in message ...

"Te Canaille" wrote in message
newsUqoc.144857$f_5.80076@lakeread01...
Its true that shortening the thwarts decreases rocker. If you want to do
both, I did see someone who cut slivers out of the side of the boat,
basically removed a triangle, to create rocker.

He cut two pieces from each side, the base of the triangle on the rail, the
point right down at the chine (even curling just a tiny bit around the
bottom, like a few mm.) The pieces were each about 1/3 the hull length from
the ends, maybe a hint closer to the center. The base of each triangle
removed about 1 inche of rail, but the resulting 'suture' raised the ends
up several inches (you can do the math).

It would be interesting: remove two slivers from each side to OVERcreate
rocker, then shorten the thwarts to round the bottom, and remove some
rocker. You'd have a pretty unique boat when you were done. Personally, I
think I'd work on the hole-in-the-sand method..

--riverman

"Te Canaille" wrote in message
news:Iqsoc.144863$f_5.86768@lakeread01...
Riverman :

Interesting. Don't reckon I need rocker badly enough to try any carving or
maybe I just don't have enough experience to give the
confidence to attempt this. Reckon I'll try some other approaches.

I'll bite, what's the "hole in the sand method" ?




Dig a big hole in the sand....put your boat in it......say a few words......

no, just kidding. I was referring to making a template in the sand, placeing
the boat over it, and pouring boiling water in it. I'd love to know if it
works.

--riverman

On Wed, 12 May 2004 16:03:19 -0000, Bill Tuthill
wrote:
riverman wrote:
Sounds like Royalex is a tradename for polypropylene. Is it?

ABS = acrylonitrilebutylstyrene Definitely not polypropylene.
Royalex is a tradename owned by Uniroyal. ABS, Royalex, and several
others are similar, but not identical, sandwiches of ABS plus foam
plus a vinyl, colored outer skin. Tom McCloud