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Re: Sheer clamps not needed for hybrid deck.
By:Bill Hamm
Date: 6/23/2009, 1:33 am
In Response To: Sheer clamps not needed for hybrid deck. (Paul G. Jacobson)

: You might as well dispose of the plywood on some other project. Or use it for
: hatches and cockpit coaming. This isn't the place for it.

: Don't work so hard. Don't make so much sawdust. Get on to the important
: work--putting on the strips. Keep reading.

: That would be overkill. Don't do it. Keep reading.

: Some ideas can be trashed from the get go. I think using plywood for sheer
: clamps on a hybrid deck is a definite candidate for the trash can.

: The purpose of a sheer clamp is to provide a strong foundation you can put
: screws into whenyou are bending a piece of plywood over the top of a kayak
: to create a deck. That plywood wants to stay flat. All the bends and
: curves build up tension as surely as stretching a rubber band. To hold the
: plywood in place those screws need something to grip. If you went with
: plywood and small screws, you would want to orient your ply so that the
: laminations were horizontal, and glued to the hull. The face of the
: plywood would then be the mating surface to the underside of the deck.
: Even if you plane or sand through the face veneer of the plywood this will
: still give the strongest grip to the deck screws.

: BUT you are NOT using a PLYWOOD deck ! You are creating a hybrid boat with a
: deck made from strips. You don't need sheer clamps at all. Your outer
: strip will be glued to the top edge of the hull panel. Run a handplane
: along that, and with a few gentle passes you will get a nice edge to glue
: to. Heck, you could smooth thinge with a sanding block. If your hull is
: made from 4 mm plywood, then your glue line will be 4 mm wide--which is
: just about the same as the bond width on 3/16" strips edge glued to
: each other.

: If you really think that edge strip on the deck needs more support where it
: joins the hull, you can rips some very small pieces from scrap strips and
: glue them inside the hull. You are not driving screws or popping staples
: or nails into these. They are just to give a bigger surface area for your
: glue. So these strips are VERY small. If you have 1/4 inch strips set your
: saw to a 45 degree angle and rip off some pieces which are triangular with
: 2 faces that are roughly 1/4" at right angles to each other, and a
: slightly longer hypotenuse. Anything over a foot long will work. Butt them
: together to cover the length of the boat. Use light clamps to hold these
: in place until the glue hardens. Cheap wire paper clips will work for
: this. Sand or plane off any high spots.

: Glue on the outer strips for the deck, letting them run straight. Once the
: glue hardens you can use a saw to cut the overhang close to the hull, and
: then plane or sand to get a smooth edge.

: The added gluing surface gives you a gluing "face" that is about 10
: mm or 3/8' wide. It is a bit more than half the width of one of your deck
: strips, so there is going to be plenty of support for the strips.

: These very small "mini sheer clamps" take the place of a fillet of
: thickened resin in that joint area. That saves you from climbing inside to
: put in the fillet. Since you'll cover the inside of the deck with glass,
: leave enough hanging over to go up the side of the hull about 2to 3
: inches. Exact measurements aren't important here. Nobody sees the edge. It
: will go over the triangular woodstrip "clamp" with no problem.
: No added glass tape is really needed unless you feel the need for
: additional stiffening or reinforcement. Personally, I'd put any extra on
: the OUTSIDE of the joint. Getting tape into the tight areas in the bow of
: a kayak is no fun, so you may not want to even try.

: Hope this helps.

: PGJ

Hi Paul,

I think he's attaching the deck the way I do it using fairly short sheer clamps at the ends back to the point that the joint is easily reached from the hatches, then taping the rest. On most boats (with hatches) that means they are about 2' or 3' long.

Still alot easier to use whatever softwood that's available, pine works fine.

Bill H.

Messages In This Thread

S&G: Ply for sheer clamps????
Craig Robinson -- 6/21/2009, 8:44 pm
Re: S&G: Ply for sheer clamps????
LeeG -- 6/28/2009, 3:17 am
Re: S&G: Ply for sheer clamps????
Bill Hamm -- 6/28/2009, 5:27 am
Re: S&G: Ply for sheer clamps????
LeeG -- 6/28/2009, 2:52 pm
Re: S&G: Ply for sheer clamps????
Bill Hamm -- 6/29/2009, 1:28 am
Re: S&G: Ply for sheer clamps????
Craig Robinson -- 6/28/2009, 8:34 pm
Re: S&G: Ply for sheer clamps????
Charlie -- 6/22/2009, 12:23 pm
Re: S&G: Ply for sheer clamps????
Bill Hamm -- 6/22/2009, 12:08 am
Re: S&G: Ply for sheer clamps????
Craig Robinson -- 6/22/2009, 1:37 pm
Sheer clamps not needed for hybrid deck.
Paul G. Jacobson -- 6/22/2009, 11:37 pm
Re: Sheer clamps not needed for hybrid deck.
Bill Hamm -- 6/23/2009, 1:33 am
Re: Sheer clamps not needed for hybrid deck.
Craig Robinson -- 6/24/2009, 6:57 pm
Re: Sheer clamps not needed for hybrid deck.
Bill Hamm -- 6/25/2009, 5:47 am
Re: Sheer clamps not needed for hybrid deck.
Craig Robinson -- 6/26/2009, 3:39 am