Is this Tsunami really kevlar?

http://tinyurl.com/757q2h (shortened link to Sierra Trading Post)



At the given cost and weight, I really doubt it. Do they even make kevlar Tsunamis?










yes
a fun boat in composite.



steve

Thanks
I’m not interested in buying it myself unfortunately, I just ran across it and was curious since it seems like a really good deal. (though it is a “factory second”)



So if anybody is interested in it, don’t feel like your “stealing” my deal, since the quantity in stock is listed as “almost gone”


They might have used Kevlar cloth
on the inside, to make the boat more impact resistant. At 56 pounds, it isn’t that much lighter than my Necky Looksha Sport in poly.



Builders often don’t explain why they use Kevlar, and sometimes builders don’t know themselves. Kevlar, besides being a relatively light fabric, is very resistant to impact and tearing. When it is used for the inside layers, it allows the builder to make a boat that is somewhat lighter than would be possible with only glass and carbon. Other fabrics can be used to increase impact resistance and resistance to propagation of tearing… examples are polyester, Nylon, and polypropelene… but Kevlar outperforms them for this purpose.



So, the boat in question may be part Kevlar. It is very unlikely that it is ALL Kevlar, because that would be stupid. Even Kruger, while they use a lot of Kevlar layers, use some glass outside.

Duralite
if you’re interested in a Tsunami that’s actually lightweight, look around for one in Duralite; Wilderness isn’t making Duralite boats anymore so they’ll be hard to come by in the future. I got the 140 and there’s a 145 on EBay right now from the same shop I bought mine from.

Likely
they are using Kevlar partials as reinforcement in the hull. Kevlar is good in tension but not compression thus its use on the inside of the laminate. At the quoted weight there is not a full layer of kevlar anywhere in that boat. I have a full kevlar Nigel Foster Legend that is a heck of a lot bigger boat that weights much less.

wanna bet?
there is a full layer of kev in our boats.



Our infusion construction makes for a heavier than usual layup.



steve

I’m not too sure that’s correct.

– Last Updated: Dec-22-08 7:54 PM EST –

You say "At the quoted weight there is not a full layer of kevlar anywhere in that boat", but I highly doubt it's possible to be so sure, just by glancing at the specs. A buddy of mine has this same boat in poly, and compared to many kayaks in that length range I commonly see, it is one big and voluminous boat. I can easily believe such a boat would weigh this much, or close to it, with a complete interior layer of Kevlar. Not saying I'm sure about that or that I know much, only that it seems believable .

Oops, I see that flatpick already addressed this. That brings up another question though - I thought infusion made a boat lighter, by minimizing the amount of void space between layers that would end up being filled with resin. Isn't infusion the process by which the really high-end canoe laminates (which provide more strength from less weight than conventional methods) are produced? Just wondering now.

Oh, double-oops. I see eric_nyre already asked this question. "Never mind".

Vacuum bagging will minimize the
space between cloth layers. Infusion could do that, if the process of infusion is managed right.

Are we saying…
That they are using exotic materials and hi-tech resin applications to get a stronger, heavier boat that costs more? Used to be able to do that by hand with FG…



Sounds a bit like GMs approach to customer’s desires.

here’s a better answer
http://www.wildernesssystems.com/tsunami-145-pro



looks like FG is 56 lb (same as the plastic version) and Kevlar is actually 51 lb. no specifics on the construction though. in Duralite plastic it would be 45 lb.

Placid Boat Works
Take a good look at the PCW site for an excellent description of vacuum infusion. Infusion is a step beyond vacuum bagging and yields a much better resin to cloth ration resulting in a lighter, stronger, stiffer boat.

Is this Tsunami really kevlar?
It’s awfully heavy for a kevlar boat of that size. The Duralite model is supposed to only weigh 45lbs.

no duralite
we quit making these. too flexy.



steve

Duralite
was “too flexy” a problem with certain models? didn’t find a whole lot of feedback about it searching old threads. I went ahead and bought a Tsunami 140 DL after discussing it with an outfitter who had experience with them, and it’s actually more rigid than I expected; doesn’t feel much different than my buddy’s 145 in the standard poly, and it has that reinforcing backbone thing along the keel line, which made me wonder why they don’t build all their sit-in kayaks that way. but I was told higher production costs and low demand also led to its discontinuation.

actually
the flex is just part of this ‘lighter lay-up’ package. the way to achieve a lighter weight in the duralite model was to use a stiffer plastic BUT use less of it. This required the internal stiffening rod and plastic console to give the hull rigidity. They still get a little wavy. The hatches, coaming and thigh braces can also suffer from the flexible nature of this lay-up.



Long as you take care of it, the DL boat should be fine.



steve

Thanks
well my initial impression at least so far is positive, especially considering the great price I got. the warnings I read about Duralite boats seemed to come from people who didn’t own them. the bottom of the Gen2 145 without the keel thing actually flexes a lot when we put it up on padded cartop racks… thus I got some saddles for carrying my 140.



Any other tips you can offer for its proper care and storage?



Sorry for getting off topic…

don’t be sorry…
just store it and transport it so the hull doesn’t deform. roto plastic is pretty EZ, maintainence-wise.



some folks soak 'em in 303 but that’s really excessive. maybe a squirt once a year.



paddle it alot and see if you can wear it out!!!



steve

Uhhhh…infusion requires vacuum
if done correcly. That’s what makes infusion work…

Never seen an “inner mold” other than a bag. I’ve worked with (in one form or another) 8 composite kayak manufacturers, and witnessed several others operations. Infusion should yield a lower resin content that straight bagging if done correctly.

Not necessarily stiffer…
That is a function of material selection and matrix schedule. Coring adds stiffness, as does excess resin.



A resin rich matrix with the same schedule will actually probably be stiffer yet more brittle. Excess resin is not a good thing.



If doe poorly, or rushed infusion can produce a matrix that is too dry and not completely saturated.

A superbly done hand lay-up is better than a shitty infusion job. All processes are good when done well.



Expedition strength composite boats are very tough and may be only marginally lighter than poly versions.