How light is too light?

So I’ve been looking for my next kayak lately and think I might have found what I am after. It’s from a local builder, so I won’t bore you with the details, but I have suddenly found myself a bit concerned about the weight.



The kayak is 5.2m by 56cm (16ft 9in X 22in) and weights just 15kg (33lbs). It is a vacuum-infused layup. I’m not hard on my kayaks, no rock hopping or anything like that, but I have started to worry about the long term reliability of such a light kayak.



Is it something to be strongly concerned about?

Maybe Thirty Years Ago
But not today with modern methods and materials. Thirty three pounds is too heavy for me. I’d prefer boats under 25 pounds that can easily be lifted, carried and launched by kids. A big plus for you is the manufacturer is local, so repairs, if ever necessary, should not be a problem? How more convenient can you get? Go for it!

Good points
Yeah, all valid points!

I’m just hoping those repairs are not going to become a constant issue. Haha

Never
Had a problem with my Ultra lightweight hulls 36 and 20lbs. How long has this builder been making hulls? 33lbs is extremely light for a 17’ boat.

depends on type of kayak…
If it’s a sea kayak with hatches and bulkheads and maybe a rudder or skeg, it seams very light. If it’s a sandwiched layup you may expect problems with it gaining weight with any small penetration.

What I know…
I don’t know how long the builder has been making kayaks all together, but this model has been around about 5 years.



It’s a pretty simplistic setup, 2 hatches/bulkheads and a skeg.

Layup
The kayak is vacuum-infused carbon-kevlar.



I recently paddled the first prototype that was made some years back, and it didn’t feel particularly weak or flimsy. For some reason I have just always been weary of carbon layups. Carbon, in my mind, seems fragile, especially when I look at all the little chips on my carbon paddles.

Carbon layups differ

– Last Updated: Mar-10-16 10:16 AM EST –

The vacuum infusion gets the proper amount of resin in the fabric to get the most strength.

Usually carbon is used with kevlar. Both have different strengths. One is better at resisting compression the other tension..I think CF is better at resisting tension and Kevlar compression. CF is quite stiff.

Some study of materials and the layup schedule is warranted. I don't have a great understanding but I do have several boats by Colden and Placid that incorporate carbon fiber and are 30 lbs or less.

If carbon fiber were weak in an application you can bet the 2014 US Olympic Bobsled Teams gear would have been made of something else.

Carbon/Kevlar
I had C/K combined weave in a Valley and it was very stiff and felt bullet proof with no problems.

Depends & Data

– Last Updated: Mar-10-16 4:28 PM EST –

Weight is one of those things. Light of more fun to use and light boats can be adequately rugged, but if one is landing on rocky shores in heavy surf justifies Verlan Kruger type 12 layer laminates.

Construction effects weight, hand lamination is heaviest, wet bagging second heaviest, infusion third and use of prepreg fabrics in an oven lightest of all. Fabric choices for lamination affect strength, weight and cost too.

There are several variations of aramid and carbon, but the most common aramide Kevlar 49, Innegra and std modulus carbon compare:
Rel. Density Ten. Stg Ten. Mod. % Elong. $/#
K49 1.44 580 19 3 $20
Innegra S 0.84 100 02 10 $20
Std M Carbon 1.80 600 33 1.5 $50

units are eliminated and numbers rounded to simplify, but Carbon is superior to Kevlar in compressive and elongated strength but costs 2.5 X. Superior intermediate modulus carbon is more expensive yet.

Bi-weave fabrics with one material on the fill, another in the warp tend to fail along one of those directions. Quad weaves where both materials run in both directions seem a stronger choice. Sped tow fabrics that virtually eliminate kink are stronger than wovens because the resin need not shatter to engage the fabric's tensile strength.
Innegra has weight and water retention advantages over Kevlar but lower strength so needs combination with glass or carbon.

Why no all carbon boats, better yet Textreme spread tow carbon boats? Cost. E Glass costs about $5 a pound, S glass, Kevlar 49, Innegra all cost about $20/#, Std Modulus Carbon $50/#, Boron $400 and Si Carbide $2500. The latter would make the strongest lightest boat but the world is probably not ready for a $100,000 kayak.

weight
Depends on who’s building the boat and how it’s done. The Thunderbolt by West Side boatshop is about 21’ long and only weighs 28 lbs. and they hold up really well.



Bill H.

Similar to Epic 18 ?
I have an eleven year old Epic 18, carbon/kevlar, 35#, tough as nails, still going strong. Wouldn’t hesitate to buy another one like this.

What do you think
Of the basalt/innegra s Nova Craft layup they are experimenting with for canoes? I don’t know if it’s a co-weave but for durability it seems to me a little give and deflection can reduce peak stress. Once you eliminate gel coat and heavy stock fittings a relatively inexpensive and durable 40 lb kayak is achievable w/o going to carbon.

ultra light

– Last Updated: Mar-12-16 8:02 PM EST –

or semi ultra light kayaks are fragile meant for paddlers needing a fragile ultra light kayak.

makes for an interesting survey: how many UL hulls are cracked over 2 seasons ?

rarely are we reading an ad sez: UL hull used once cracked in half: cheap.

so UL must be reliable.

my 17'+ Solstice Titan is expedition Kevlar, is durable.

I try treating it gently but I'm a clod. The hull is lightly bashed against ground when lading (1), docks (13 ) door jambs (9) ..... solid.

weighs maybe 55 pounds.

the problem is length n pendular motion. There is a lot of fiberglass from 8-0-9'

West Coast paddlers would say the Kevlar Solstice is light duty.

Your question overburdens great humor...mostly caws we doahn own one.

feedback
who is the builder get some feedback.

yes and
consumers reports. A second survey. Whose there ? graying thin EE’s out of tai chi class ? or heavy equipment operators covered at 75% with tattoos ?