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Huh? Why?
By:Paul G. Jacobson
Date: 11/7/2001, 11:01 pm
In Response To: Re: Other: Vacuum bagging a la Red Green? (Bill Sivori)

: I am starting on a Chesepeake 14 for my wife and am considering no shear
: clamp at all, at least not a permanent one. My thought is to hot glue the
: shear clamp to the outside of the shear panel, build the hull as usual,
: but before glassing the outside of the hull attach the deck to the shear
: clamp with screws, fillet the hull to deck seam, remove the screws and
: shear clamp, trim the deck to the hull, and glass the outside of the hull
: and deck.

: My concern is on the deck beam. I would rather not use it either. I am
: thinking a temporary form in it's place and remove it after the deck
: glassing is complete. My worry is will the deck curvature and beam of the
: boat remain after I remove the temporary form?

: Any thoughts?

Why do you want to do this? Do these pieces of wood offend you or take up to much interior space? Is this an engineering problem you wish to solve?

Certainly what you propose can be done, but it will take you longer, and cost you more. After all, you are paying for the shear strip and also for the glass tape and resin that will replace it. You'll need to fabricate something to serve the purpose of the deck beams, too.

The analogy I am thinking of is that you are trying to build a house with no foundation or rafters.

The sheer and deck beams serve roughly the same structural purpose in kayaks like this as the gunwale and thwarts serve in a canoe. They are the skeleton. Now there are lots of animals without skeletons (clams, lobsters) and they are held together by strong shells. If you want to build a boat that has no "skeleton" then you'll have to create a strong shell-like structure. Strip built boats do this. Some stitch and glue designs will also work, but not all.

In your case you are replacing a wood gunwale, or sheer chine, with a molded in replacement, in the form of a strong fillet. That will probably work fine, as the fillet will be a nice continuous length of fiberglass. A lot of S&G boats do that. But, you may want to totally redesign the deck if you are going to leave out the deckbeam. You'll need some internal support to keep the boat from squeezing together from the pressure exerted by the water on the outside of the hull. The more you load the boat the greater it submerges and the greater the pressure. A difference of 1/10th of a pound per square inch adds up quickly, as you have a lot of square inches of hull under the waterline. You have reason to worry about whether the beam will remain the same as the design -- and that is with the boat still on the land. Put it in water and it will get narrower. If it compresses so much that it fails, you certainly don't want to be trapped inside such a thing. Think safety, and either keep the deckbeam, or design a deck that has strength in that direction.

Hope this helps

PGJ

Messages In This Thread

Other: Vacuum bagging a la Red Green?
Nathan -- 11/7/2001, 5:47 pm
Vacuum pumps a la Red Green!
Dave S. -- 11/8/2001, 11:34 pm
Re: Vacuum pumps a la Red Green!
Don Beale -- 11/9/2001, 11:23 am
Vacuum bagging a la Green Giant?
Paul G. Jacobson -- 11/7/2001, 10:19 pm
Wow - thanks. Responses...
Nathan -- 11/8/2001, 2:03 am
Re: Satinweave Glass, etc...
Mike Hanks -- 11/8/2001, 8:22 pm
Re: Wow - thanks. Responses...
Paul G. Jacobson -- 11/8/2001, 6:14 pm
Okoume in SF Bay
Val Wann -- 11/8/2001, 10:58 am
Re: Okoume in SF Bay
Lee,G -- 11/8/2001, 12:15 pm
Re: Okoume in SF Bay
Matthew Blumenthal -- 11/8/2001, 8:06 pm
Re: Okoume in SF Bay
Val Wann -- 11/9/2001, 1:06 am
Re: Okoume in SF Bay
Rehd -- 11/9/2001, 1:53 am
Re: Okoume in SF Bay
Lee,G -- 11/9/2001, 2:21 pm
Re: Wow - thanks. Responses...
Dan St. Gean -- 11/8/2001, 9:29 am
Re: Responses...VacBag
Jim Kozel -- 11/8/2001, 10:47 am
Re: Other: Vacuum bagging a la Red Green?
Val Wann -- 11/7/2001, 7:06 pm
Re: Other: Vacuum bagging a la Red Green?
Bill Sivori -- 11/7/2001, 9:44 pm
Huh? Why?
Paul G. Jacobson -- 11/7/2001, 11:01 pm
Re: Huh? Why?
Bill Sivori -- 11/9/2001, 7:53 am
Re: Huh? Why?
Dean Trexel -- 11/7/2001, 11:21 pm
Re: Other: Vacuum bagging a la Red Green?
Dean Trexel -- 11/7/2001, 10:29 pm
Re: Other: Vacuum bagging a la Red Green?
Bill Sivori -- 11/9/2001, 8:09 am
Thanks! Responses...
Nathan -- 11/7/2001, 7:18 pm
Re: Other: Vacuum bagging a la Red Green?
Shawn Baker -- 11/7/2001, 6:45 pm
Vacuum bagging really necessary?
Dean Trexel -- 11/7/2001, 6:25 pm
pool noodles
Sam McFadden -- 11/7/2001, 8:42 pm
Re: Other: Vacuum bagging a la Red Green?
Pete Rudie -- 11/7/2001, 5:56 pm