Why does my "68lb" triple weigh 90lbs?:)

Ok gang, here's a question for you... I just finished my first build (a triple). I figured it would be a tad bit over the spec'd 68lbs because of my extra epoxy coats, my sloppy cockpit that has quite a few wrinkles, and my large fillets. But I swear I must have sanded off ten pounds of "extra" epoxy getting the cockpit, hull and deck smooth... so, why do I have a 90 lb boat? Granted, this tub did use every bit of the 3 gallons of supplied epoxy:)

The boat is still dream to paddle, the Mrs. started complaining, during our frequent loading and unload while on a recent San Juans trip, that the new boat seemed a lot heavier than the old plastic singles (65lbs)... I mentioned that it probably was indeed heavier, but more like 75 or so... the scale told a different story:) 

How off have the weights been on some of your builds?

 


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RE: Why does my "68lb" triple weigh 90lbs?:)

Hahahaha, BOY!!!! can I relate!  My first yak (Expedition Single) which was suppose to weigh in at 46 finished at 94 pounds.  Everyone told me it was to much epoxy, but I actually used less than spec'ed.  I made my strips from popular, cherry, and mahogany.  And it came out 6 inches longer than spec'ed.  It was indeed pretty, but you prayed for no portages.

My 2nd build (Guillemot L) came in just 4 pounds over and it was all cedar.

3rd build (Redfish King) came in 6 pounds over and it was cedar and padauk, and I used more specialised hardware that weigh more than kit stuff.

LOL  I am in the middle of my 4th build (Spring Run) and already planning my 5th.  It will be of my own design so I have no specs to follow.

So the moral of this story is keep building till you get it right.  LOL

RE: Why does my "68lb" triple weigh 90lbs?:)

Simply put, you probably used too much epoxy.  First time builders almost as a rule use too much epoxy.  Also, I think CLC has majorly under stated the weight for the triple.  94 pounds is about average for that boat actually.  Using shear clamps and the huge fillets specified in the instructions adds a ton of weight.  As a first time builder you may have made your fillets too large, used too much epoxy coating the non fiberglassed areas, used too much in filling the weave of the glass, made the mistake of filling the weave on the interior of the boat, or you could have made the end pours too large.  I did all of these things when I built my CLC Triple.  I probably came out around 100-110 pounds.  I even had John Harris help me carry the boat at the Port Townsend Wooden Boat Festival a few years back and he assured me that for a first time builder, the boat was not that heavy in comparison.  

 As kayakkev says, with practice you will refine your skill and the boats you build will come out lighter.  (unless you build them out of heavy hardwoods like solid mahogany, I would not have wanted to sand that boat!) 

RE: Why does my "68lb" triple weigh 90lbs?:)

3 gallons of epoxy is 24 lbs or so, depending on the fillers and such, so that puts you right in the ballpark of actuality. Varnish & paint add a fair amount of weight, too.

Casey pretty much nailed it with his list. He and Kev are also right that practice makes lighter boats. The manuals from CLC are pitched toward solid reliable results from total beginners, as well as speeds fast enough for week-long classes.

For example, those mile-wide fillets with the blue tape edges that are applied from pastry bags are fast, clean and reliable, but use roughly eight times the material that tacking, pulling the stitches and then applying fillets with a rounded putty knife does. But the lighter method takes at least 2 days since the tacks have to cure hard, so it can't be used in a 5-day class. It can also result in popped seams if not done right, so it's not safe to recommend to total beginners. Hence the wide seams in the manuals.

But as individual builders' skills progress, they learn when and how to take risks. So the seams get narrower, the glass gets sanded more agressively, etc. and the next boat finishes lighter.

In the meantime,you could blame it on an inaccurate scale :-)

Laszlo

 

RE: Why does my "68lb" triple weigh 90lbs?:)

As others have said, 90 lbs sounds about right for a triple built to specs from CLC.  Just think, if you had such a beast in tupperware it would weigh at least 120.  Don't think of it as "lord this is heavy", think of it as "it could be worse, I could be carrying a plastic barge".

CLCs sheerclamps are too large, their fillets are too large, their glass is too heavy, and they recommend too much epoxy.  They have to for insurance reasons as well as the class speeds that Laszlo mentioned.  If any of the boats they sell failed, they'd have some potential lawsuits to deal with and this helps them cover themselves (and they should).  I think you will also note that it's very rare for one of the CLC staffers to comment positively (on this board) on design modifications such as I often recommend about shaving down the sheerclamps or leaving out deck beams.  It just doesn't behoov them financially to "cut corners.  

As builders we have the option of strictly following the manuals or veering from them, even significantly.  Many first time builders choose to stick to the tried and true method that the manuals offer, which results in a generally heavier boat.  They paddle just as well though and can take out a small tanker in a head on collision, so that's not so bad.

FrankP

RE: Why does my "68lb" triple weigh 90lbs?:)

Laszlo, can you elaborate a little on "appropriate sized" fillets and epoxy coatings?

I'm just starting to put the fillets into my boat (have to wait for the rainy weather to end - dang humidity!), and would like to use an appropriate amount of glue - enough for strength/regidity, but not so much that I'm over doing it.  I've purchased several plastic spatulas to form the curved fillets so I've got several options for the size of each joint.  I bought 4" tape (3" wasn't available) and now, after reading your post, am considering halving that and using 2" tape on the bilge/side seams, and the 4" down the centerline.

Any advice/suggestions/insights would be appreciated,

Thanks,

Larry

RE: Why does my "68lb" triple weigh 90lbs?:)

Water is 8 lb. a gallon. Epoxy is approximately 9¼ lb. per gal. Mastering a minimum useage of epoxy takes some experience and a certain amount of restraint. More is not always better.

If you want to build light you must keep that goal in mind. Every step you take should judged as to whether it will add weight. This is especially important if you want to cartop. 

I'll never forget a thread I read elsewhere about an S&G pram that was supposed to weigh 55 lb. The builder complained, "My pram is very heavy. It weighs 93 lb. and I'm not done yet". When he revealed how many times he exceeded the recommended scantlings and the amount of epoxy he used it was fasirly obvious where the excess weight had come from.

RE: Why does my "68lb" triple weigh 90lbs?:)

Probably the same reason my 62lb Mill Creek 16.5 weighs 85lbs.

 

It's bomb proof with 1/4" hull, glass inside & out, beefier sheer clamps, beefed up bow & stern to accomodate padeyes strong enough to lift the kayak.........

 

Anything worth doing is worth overdoing..........

 

As my first build, I am very proud, but might blow out an O-ring lifting her on my own.

 

http://www.facebook.com/photo.php?pid=30649013&l=3dadb5a43f&id=1376837575

 

Sitting a little low in the water. (fixed by switching seating positions & unloading picnic supplies)

 

 

RE: Why does my "68lb" triple weigh 90lbs?:)

Larry,

I wouldn't go with the thinner tape. The tape's surface area is what gives the seam its strength. Make it too narrow and you won't have a decent allowance for feathering the edges smooth, minor defects, etc. Properly wet out, the tape isn't where the excess weight is, it's in the fillet.

My WD12 blog has a section on fillets that should answer your question. Click on the picture to get to it. Let me if you still have questions.

Laszlo

 

RE: Why does my "68lb" triple weigh 90lbs?:)

It couldn't account for 22 lbs. But I've always assumed that "hull weight" meant just that. The weight of the bare hull? If that is correct, then you would have to add the weight of the foot braces, rudder, cables and rigging. Just a WAG but maybe that might start to approach 5 to 10 lbs on a large kayak?

FWIW, as a fairly inexperienced builder, my boats (CH17LT and Shearwater 16 hybrid) came out exactly as spec'ed. I tended to have more of a problem with getting very thin coats and may have taken as many as 5 or 6 to really fill in the weave. I was always a little paranoid for some reason about running out of epoxy and perhaps that motivated me a little bit to be conservative.

--

Ogata

RE: Why does my "68lb" triple weigh 90lbs?:)

To summarize our collective response (see above): 1. in fact, your boat does not weigh at all more than expected, and 2. the reason for the fact that it weighs far more than expected is that you used too much epoxy.

Note: We of the forum are huddling to resolve some minor difficulties with what they call  "logic"; we will get back to you when we sort it out.

;-)

RE: Why does my "68lb" triple weigh 90lbs?:)

Laszlo, went to your site - excellent info and I put it to good use tonight.  Because I left the wires in the boat (unintentional, until the goo from my plastic baggy started saturating everything in sight!), so I had to go slightly larger than the nickle radius you recommend, but not much more.  I used a flexible spatula, which allowed me to very the depth according to the sharpness of the joint, very happy with the results.  Will finish them up tomorrow and tape (and as you said, will keep the 3" widths).

Thanks again,

Larry

RE: Why does my "68lb" triple weigh 90lbs?:)

Camper,

"A foolish consistency is the hobgoblin of little minds." We do try for consistency here, but not sure if it should be peanut butter or mustard, chunky or smooth, ballpark or honeycup. Until that gets sorted out, we'll continue with the Schroedinger's Cat approach to boatbuilding. That way we can have our cake and eat it, too. (Have I left anything out?)

Larry, glad to have helped.

Laszlo

 

 

RE: Why does my "68lb" triple weigh 90lbs?:)

Oh, I thought Schroedinger's Cat had died ....

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