Nova TuffStuff Royalex replacement?

This video was just released and seems to be generating a fair bit of interest:

I gather from the video that this “new” material is basically an Innegra H hybrid consisting of Innegra S and basalt fibers:

I know that Innegra S has been used for construction of surfboards and has generated some interest in laminate construction for Formula 1 race cars. There were a few threads several years ago discussing the use of Innegra for canoes and kayaks and some were predicting it would replace aramid, but this doesn’t seem to have happened. Wenonah was using it in their “Barracuda” layup, but I believe they discontinued that.

Does anyone know if this has been used by other canoe makers? Since Innegra S is over 90% polypropylene, what will its resin adhesion be like? Will it be prone to delamination over time? Most importantly, will it be possible for the amateur repair type to fix cracks in this material using conventional fabrics and resins?

Resin adhesion to Kevlar is about 15%
below average for fabrics, but adequate. Resin adhesion to polypropylene fibers was always crummy, except for polypropylene resin.

Well, that was my concern
that if Innegra laminates required a polypropylene resin, the result would be a material difficult to repair since nothing much wants to chemically bond to polyethylene.

I am too dumb to fully interpret this resin compatibility data from Innegra regarding Innegra S, but it would seem that multiple epoxy and vinyl ester resins stick to the stuff:

Someone made the valid point that
hammer blows do not much resemble the typical boat wrap incident, where distortion is greater and lasts longer.

I would like to see if
a tuffstuff canoe that has been wrapped can be kicked back into shape and paddled off the river. If so - I think I’m sold.

Innegra Data

– Last Updated: Oct-13-14 10:16 PM EST –

I was working with Innegra samples half a decade ago, stopped when a friend asked why I was wasting time with stuff that made ugly boats. It's now available in bi-spin and bi and quad weave with glass, basalt and carbon.

It is lighter than Kevlar, hydrophobic compared to Kev's hydrophyllic, and has coarser strands so bonds better. Its tensile strength and tensile modulus do not compare well and it's elongation is 3X Kevlar's.
It is also bulkier than Kevlar, so requires the compression of vacuum bagged construction to minimize resin %.

It has found use in sheathing thick laminations like rigid hull inflatible powerboats and race car chassis.

Now just how we best use it in paddlecraft laminations running 40 mills thick and in what configuration is a question that several of us are working on. Stay tuned, but remember to breath.

One of the characteristics of Royalex

– Last Updated: Oct-12-14 9:56 PM EST –

that I like for tripping canoes is that it does not stick to rocks. It will flex and slide over rocks. Is that because of the flexibility or the soft surface material or what?

Mostly the soft vinyl surface material.
I have run over rocks in very thin, bendy composite hulls, and whether they stick depends on the frictional “grab” of the rock, and the ability of the boat surface to slide on that rock.

Hull flexibility helps on some rocks, not others.

Seems like the “slipperyness” of the
outside surface of the hull might be a factor as well, not just type of rock. I know for example that when paddling recently on a trip in low water my wood canvas canoe was sticking to the rocks a lot more than my buddies royalex hull. Same rocks, different stickiness. Broke a few ribs too - but that is a story for a different day.

looks interesting
I’m no materials expert, but given the wide range of current applications it seems like it has a pretty good track record. The canoe in the Novacraft video seemed to handle things pretty well. I certainly would never consider doing any of that with any of my composite boats. It will be interesting to see where this comes in price-wise and what folks have to say about it after it has been in use for a while.

With the same calibrated hammer
blow, my SS/KK Millbrook would be locally damaged in some places, but would just bounce back and shed the blow in others. Hull flexibility can reduce damage.

But the river isn’t full of hammer blows. More like hydraulic crunchers.

Still seems impressive

– Last Updated: Oct-13-14 9:50 PM EST –

Considering the fact that most composite boats would likely be damaged by such hammer blows, and any of the Royalex boats I've handled/paddled would have been dented, that demonstration looks encouraging. Where there's risk of damage other than in boat-pinning accidents, and accidental collisions are surely a lot more common, I think this material looks promising. The flexibility test looked promising too, as far as making it appear likely that a boat could survive being pinned in many cases. Granted, none of that was scientifically done, or done in a way that makes it easy to compare to real-world situations that might damage a hull, but I don't own any boats that could survive those hammer blows unscathed, or whose material could survive being flexed that severely.

I remember seeing a similar hammer demonstration on the site of Clipper (Western?) Canoes, but on boats made of a much different material (I can't recall any details about the material).

Clipper Kevlar Duraflex

– Last Updated: Oct-13-14 10:08 PM EST –

Basically a heavy duty all cloth layup consisting of S 'glass and Kevlar:

MYCCR has a more in depth discussion on Innegra, complete with images. It is strangly placed in the Equipment forum not Materials and Construction??

Cost for basalt and Innegra cloth?
Seems to me this is going to be more of a composite option than a Royalex replacement.

I wonder how a non-core heavy Kevlar layup or other laminates built for flexing impact compare.

That’s what I mean
We’ve got an old Necky Tofino kevlar tandem and it’s easy to push the hull in on broad areas between the bulkheads, it’s been rented and abused for years with no laminate failures. Seems to me a solid laminate that is allowed to flex can handle a lot of impacts.

Some companies (MR, Wenonah)
have had good luck with all Kevlar. But remember, reasonably thorough tests done in the “Boatbuilders Guide” showed clearly that SSKK was much better than KKKK, because of K’s lack of compression strength.

You’re right. Royalex and the best
composite layups behave so differently in a whitewater wraparound that it is hard to make a direct comparison. And the composite boats are often stiffer, better performers, lighter.


– Last Updated: Oct-20-14 7:21 AM EST –

I am going to miss royalex a lot. For my kind of canoeing there is nothing that equals royalex. I am 63 years old and I own two old royalex boats so I guess I will be fine. But it is hard to believe that any composite is ever going to match royalex for the kind of applications some us us need - namely long trips in extremely remote areas with a mixture of whitewater and flatwater. I just hope the folks that are renting canoes in the far north stock up on the standard fleet of trippers and nova craft prospectors so that I can find good rentals over the next 5-10 years. RIP royalex.

I say all this having just supposedly "sworn off plastic" and converted to wood canvas. Well, maybe I overstated things a bit in my old posts on that topic. :-)

Material Costs
E Glass costs about $5/lb, Basalt $10, S glass and Innegra S $20, Kevlar 49 $25 and std. modulus Carbon $50. Just for scale, Boron is $400/lb.

Of course bi or quad weaving and co-mingling or bi-spun thread up costs due to complications in handling. As it stands, the quad weaves with Innegra are visually attractive, [Bic’s Tracer SUP], but fabric woven from bi-spun threads delivers improved impact resistance.

Co-mingling with basalt provides relatively low cost material, using carbon ups price and performance while lowering sq. yd. weight.

More data, in a month or so.