Composite river layup without foam core?

-- Last Updated: Aug-05-13 10:12 PM EST --

are there any composite layups without foam core suitable for bony rivers?

I heard foam cores are difficult to repair if they break. In a recent thread, the Plaidpaddler mentioned Wenonah's now defunct center rib lay-up without foam core as a lay-up that was intended for rougher waters. It sounds like a good idea. What was its sucessor and what lay-ups do other manufacturers offer that are both suitable for shallow rivers as well as lacking a foam core?

Tuffweave
I’ve had a couple Wenonah tuffweave canoes that held up well on bony Ozark streams. None had the center rib. Haven’t had one recently, but had good luck with them in the past.

The successor to flex rib
Was a foam core. Old Mad Rivers were pretty much solid composite .

Among Others
Colden, Hemlock, MillBrook and Placid still use all cloth construction.

foam core?
I assume your boats had the foam core construction? These days, Wenonah offers composites in either ultra light or foam core, both not ideal for rivers.

Tuff Weave uses no foam core
Tuff-Weave boats don’t rely on a foam core for strength. I’m no expert, but so far, I’ve only seen foam-core construction on boats that can be considered “ultra-light”.



As long as I’m writing this, I’ll mention that p-net’s Sloopsailer has a composite Nova Craft Supernova. It’s been used on rocky rivers and never coddled, and it has held up well. You can ask Sloopsailer what the layup is. I know it has no foam core, and it’s a good swift-water river boat for a person who’s fairly tall or big, or who needs carrying capacity. I use a Royalex version, and it’s not quite as nimble as the composite model, though another person here once reported that it’s hard to tell the difference between the two. Perhaps the Royalex version feels so different to me mostly on account of being heavier.

My reading of the Wenonah catalog
is that all Tufweave canoes now are foam core. As for their Kevlar canoes, the ultralite canoes are foam core with a very rigid core and side ribs. The “Flexcore” canoes have a bottom that, uh, flexes a bit.



Foam cores came about for a good reason. Even a canoe that has a rounded “shallow arch” like our old Moore Voyageur are highly inclined to oil can. Our Moore has plenty of glass, including an inner layer of stiff woven roving, and it has a longitudinal strip glassed in. But it flexes quite a bit over the waves, or it did until I put in vertical struts between the thwarts and the longitudinal strip.



Repair issues with foam core may be exaggerated, or not based on the best examples. Recently I saw a 20+ year old Bluewater, well used, with a flexible foam core, and there had been no serious repairs. But the Bluewater layup folks also made slalom kayaks and c-1s, and so may have known more about how to do a foam core.

Yeah, if you count a thick layer of
Spheretex in some Millbrooks as other than foam core. Haven’t broken mine yet, but I don’t look forward to it. I’d rather fix the flexible foam core on our Bluewater.

I would rather fix foam core than raised
ribs. There have been whitewater layups with flat ribs, essentially just an extra layer or two of fabric running around the hull from gunwale to gunwale.



An option that is left to the buyer, and not installed by manufacturers, is to put a longitudinal strip down the center, and then to add vertical struts or support between the thwarts and the longitudinal strip.



When we reported flexing in our heavy, glass-rich, Moore, the company sent us telescoping struts, using auto valve springs inside, to install between the thwarts and the bottom. I never tried them. I used solid spruce struts for a while, and later I put foam pedestals under every thwart.

Tufweave w/foam
Our 16’6" Wenonah Sundowner (~1990) is TufWeave with a full foam core along the floor with ribs up the side. At the time, I think you could select fabric (TuffWeave, Kevlar) and pair that with a particular construction (all fabric, center-rib, cross-ribs, or full foam core – in order of decreasing weight and suitability for boney water). Don’t know if Wenonah still offers all these options, or only offers a subset for each fabric type now.

Bell White Gold had a core - it wasn’t
ultra light. I don’t know if it was a foam core.

Tuf-weave Flex Core
The Wenonah Tuf-Weave Flex Core boats (which appear to be the only Tuf-Weave boats Wenonah is currently making) utilize a foam core: http://www.wenonah.com/craftsmanship/composites.php