Boreal Design... Bulga advice

[spider]

Hi, We are planning on getting a Boreal Designs Beluga for our tandem to do some more of "expedition" style trips up north on the St Lawrence etc.

On one hand we want the lightest version for loading on & off the car.

But

Isn't there something about Kevlar and Carbon being strong but brittle. Is there anything to that ??

Right now I paddle a Eddyline Night Hawk, made with some kind of Carbon mix.

It has held up fine these past few years and has survived a sharp rock or two in it's day, with no problems

So...whats your thoughts??

Is all kevlar the same or are there different qualities etc...?

[Gcosloy]

Hi, We are planning on getting a Boreal Designs Beluga for our tandem to do some more of "expedition" style trips up north on the St Lawrence etc.

On one hand we want the lightest version for loading on & off the car.

But

Isn't there something about Kevlar and Carbon being strong but brittle. Is there anything to that ??

Right now I paddle a Eddyline Night Hawk, made with some kind of Carbon mix.

It has held up fine these past few years and has survived a sharp rock or two in it's day, with no problems

So...whats your thoughts??

Is all kevlar the same or are there different qualities etc...?

I owned a Kevlar Ellesmere and found it very light but somewhat flexible. I once sat on the hull with the yak upside down in the woods and cracked the gel coat because of this flex. On, the other hand if I were to smash into some rocks I'd rather do it with Kevlar than FG which just might puncture because of it's stiffness. The build quality of Boreal is probably the best in the industry. I would definitely recommend them.

[Phil Allen]

Gene has the details right.

Kevlar is amazingly tough, but rather flexible. That's one reason it works in things like flak jackets. Carbon fiber is also extremely strong for its weight and rather stiff. So many current light weight lay-ups use carbon reinforced kevlar or carbon reinforced glass to get the best mix of strength to weight. The only downside if I remember my chemistry is that the epoxies used for carbon and kevlar are different, and more difficult to work with, than those used for fiberglass. So doing repairs at home is more challenging. I'm sure others can clarify that last point.

Phil

[EEL]

Right now I paddle a Eddyline Night Hawk, made with some kind of Carbon mix.

Eddyline boats are made of a very good material they call Carbonlite, but it is not a material containing carbon fibers. The term is confusing now that carbon/kevlar composites are used more in kayaks. The Eddyline boats are build from sheets of a plastic laminate while carbon/kevlar boats are composite boats made using various combinations of cloth containing carbon fiber and/or kevlar.

You can go bonkers on the techy side of things regarding the composites boats are made with and various pluses and minuses of each.

While a topic that engenders much debate, if weight is an issue, then the lighter layups using some combination of carbon and kevlar are a good way to go. I would not be concerned about a boat from a good manufacturer being adequately strong.

My experience with a carbon/kevlar Impex boat has been very good and it has proven to be tough. I suppose it might be more flexible, but that does not mean it is not tough.

Ed Lawson

[subaruguru]

All good input.

Carbon fiber is EXTREMELY stiff, now being used in things like my buddy's guitar necks and bodies, as well bike frames due to its stiffness/strength-to-weight properties.

Kevlar is strong yet quite flexible...a mixed blessing for speaker cone use, for example.

It's really about the RESINS' properties, I think. I noticed that although the C/K layup in my clear hull Cetus is quite flexible, the composite's brittleness AT THE KEEL EDGE was problematic in that the resin simply crazed and crumbled when fractured. The underlying C/K remained intact, accepting two-part epoxy well for a build-up repair.

It's interesting to note that the hull walls are quite flexible, which slightly concerns me. A similar C/K construction with added pigmented heavier gelcoat (Impex Force 5) seems stiffer and more solid, so i won't be using the clear-hull Cetus in the rocks!

I remember reading many years ago about the problems Trek was having with their new OCLV carbon frames completely fracturing when crashed. Here's a case where adding Kevlar for impact strength would reduce stiffness so much as to be unusable, so it was a matter of getting the carbon geometry perfected; but for kayaks C/K interwoven fabric sheets seems pretty ideal except for price.

I'd go for it and just bring some 2-part epoxy and 2" wide industrial Velcro backing on a long trip. I buy the 25' rolls at HD for auto use if you want just a few feet; makes useful protective keel strip ends too, and probably saved my Cetus from far worse keel edge fracture.)

Best,

Ern

[risingsn]

Eddyline boats are made of a very good material they call Carbonlite, but it is not a material containing carbon fibers. The term is confusing now that carbon/kevlar composites are used more in kayaks. The Eddyline boats are build from sheets of a plastic laminate while carbon/kevlar boats are composite boats made using various combinations of cloth containing carbon fiber and/or kevlar.

You can go bonkers on the techy side of things regarding the composites boats are made with and various pluses and minuses of each.

While a topic that engenders much debate, if weight is an issue, then the lighter layups using some combination of carbon and kevlar are a good way to go. I would not be concerned about a boat from a good manufacturer being adequately strong.

My experience with a carbon/kevlar Impex boat has been very good and it has proven to be tough. I suppose it might be more flexible, but that does not mean it is not tough.

Ed Lawson

Just an FYI. Some early Night Hawks were made with carbon/kev (I almost bought one). They also made some boats w/ carbo/kev & than put the Corbonlite over it instead of gel coat.

[PeterB]

The Beluga is a fine boat, fast and seaworthy. I would recommend getting one in fiberglass, which weighs about 81-83 pounds, a very good weight for such a large boat.

One flaw of the Beluga is that it lacks perimeter deck lines, so I would recommend installing these.

The standard Beluga , I believe ,comes without a middle bulkhead , between the rear cockpit and the center hatch, which creates a huge center compartment ,great for storage but not so great in the event of flooding, (capsize or surf landing etc.) If you can, get one with an optional bulkhead here, or see about getting one retrofitted.