Royalex vs. Kev-Flex core

-- Last Updated: May-30-09 11:28 AM EST --

I have a question concerning canoe hull shape. I have both a royalex and a kev- flex Wenonah Wilderness and am surprised at how different these boats are. The hull on the royalex has a nice arch to it. The kev-flex hull is a lot flatter with a more pronounced "bubble". The bow lay-out on the kev-flex is also lessl and the stern is skegged a little. I'm liking the royalex version because it feels more lively to me. Is the flatness of the kev-flex hull due to the core? Would the ultralight layup tend to have a more arched bottom than the flex core? The nearest boat for comparison is 4 hours away. Thanks for your input.

I doubt that the ultralite would be more
arched. If so, the difference would be small.

You’re pleased by a side effect of Royalex deficiency, its relative lack of stiffness. They had to mold the Royalex boat with more arch to keep the bottom stiff. You end up liking the result, even though that is probably not what the original design called for.

Flex core

– Last Updated: May-30-09 4:13 PM EST –

I have a bunch of Wenonahs and I like them all. I have 2 royalex (a solo and a tandem); 2 ultra light (a solo and a tandem); 1 flexcore tandem without a gel coat; and 1 flexcore solo with a gel coat. My experience with Wenonah canoes with just paddlers aboard and no gear load is that a tandem royalex boat is going to oil can (bubble per your terminology); that a tandem flexcore without a gel coat will noticably flex in even moderate waves; that a solo royalex bottom slightly flexes more than it oil cans up; that a solo flexcore will slightly flex in moderate waves; and that the ultra light hull bottoms do not flex or oil can (read hold their shallow arch shape) no matter what the conditions are. If you put a gear load in the canoes;.... the tandem royalex boats still oil can wherever they can; the flexcore hulls have no noticeable flex in moderate waves. In my experience Wenonah's ultra-light hulls are the most rigid whether they are paddled empty or with a load and therefore hold their shallow arch better than royalex or flexcore. Your milage may vary with your load.....

I have an old Paddler comparison test
in which they evaluated a Spirit II in the Royalex group and also a Spirit II in the composite group. It was Kevlar, and I believe it was Flexcore.

The reviewers said they were surprised and delighted at how well the Royalex boat handled on rivers and in easy whitewater. They said the Kevlar boat was not as maneuverable. Could have been just the sharper stems, or it also could be that the shape of the Royalex boat made for easier handling.

And I have other royalex boats

– Last Updated: May-30-09 6:48 PM EST –

by other makers. Swift and Bell. Tandems.
They do not oil can empty even after some brutal journeys to Hudson Bay which you would think had thinned down the skids as there was a rock or two we did not miss.

To me oil canning is a symptom that something is not structurally right..and for sure an arch is the strongest. For a while a couple of years ago I heard from my canoe shop that the Royalex was coming out too thin..and hence some boats sprouted coordinted skid plates.

Funny my Rx Argosy is pretty rigid..not as rigid as composite hulls but what little give is acceptable..

And one boat that really annoyed me with sides oilcanning is a Wenonah Odyssey in UL layup. Not to say that it did not take us many places but to the rhythm of "boom boom". The oilcanning being on the side did not worry me.

Sorry Folks
We may be having a terminology problem. I’m not talking about oil canning.The Royalex boat does oil can some but that doesn’t bother me so much.The bubble I’m talking about is the bulge built into the hull basically between the waterline and the tumble home.On the Kev-flex it’s more pronounced than on the Royalex version. And the Kev-flex definitely has a flatter bottom. I guess it’s the flatter bottom and the sharper stems that make the Kev-flex version feel less lively to me. My question really is did Wenonah make 2 different hulls or did the core on the flexcore flatten the arch? Then, would the ultralight version have an arch more like the Royalex version since the ultralight has no core? Sorry for the confusion and thanks for your replies.


Some Possibilities
Clarifying your use of terms helps, so thanks. Is it possible that the flex core (foam core?) flattened the bottom of the boat? I suppose it is possible, because there has been talk here at various times about how older Bell canoes with foam cores had flatter bottoms, because in those days they didn’t have an oven for heating the foam which would allow it to bend and conform to the mold without wanting to “spring back” when released. Is this a problem at Wenonah? I highly doubt it, but they might tell you if you ask them nicely. :wink:

I do know ONE thing for sure. Royalex and composite versions of the same boat are never the same, so this is not something that is peculiar to Wenonah. Usually people who have tried two versions of the same boat are less happy with the handling characteristics of the Royalex model, but the opposite is certainly possible, depending on what the actual differences are, and what characteristics you value in a particular boat.

Kev ultralight does have a foam core.
It’s a different core than the flexcore, but it does have a foam core.

You know…
I’ve been thinking about this all wrong. I was assuming the Royalex version came first and that the same mold was used for the composite version. I’m fairly ignorant about canoe manufacture. Now I see that the composite Wilderness jibes with other Wenonah solo designs and that due to the peculiarities of Royalex the Royalex version becomes a different boat, as g2d pointed out. As we say in Boston “Dawn breaks on Marble-head”. Thanks all.


Princess Di was a Royal ex.

and her mold had
nice lines…

Do you think she would have been sharper in a composite…

never mind…I better go paddling.

tufweave vs. royalex
I hadn’t compared the bottom of my tufweave boat to a royalex one that I paddled briefly, but the sides were exactly as you described -the flare/bubble/whatever you want to call it ran further up the side on the royalex boat. Consequently, I could heel the royalex boat further and still feel confident than I could the tufweave boat.

I was surprised because when I compared a royalex Rendezvous to a composite Rendezvous, the opposite was the case - the bubble/flare ran much further up the side of the composite boat.

I would have preferred the composite Wilderness to be the same on the sides as the Royalex boat, but it isn’t.

Hey c2g
I wanted to get up with you at Trap Pond but somehow never ran into you.

That’s just what I’m talking about. The second day out in the composite boat I flipped it on a calm windless lake. I can count the number of times I’ve done that on zero hands. I blamed it on the bulge or whatever you want to call it. I’ve never come close to dumping the Royalex boat on flat water. I was a little annoyed that the boats weren’t the same. I was hoping the composite would handle the same as the Royalex but be a little more efficient. Now that I’ve wrapped my mind around the differences I’m appreciating them. I lowered the composite seat by hanging it under the seat brackets which has made it a little more stable. It moves along nicely with a bent shaft or a double blade. Hope to catch up with you down the road. Thanks