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Re: 3rd kayak
By:Mike Hanks
Date: 10/10/1999, 11:17 pm
In Response To: Re: 3rd kayak (Paul G. Jacobson)

Paul,

Thanks for your extremely constructive and thought provoking ideas. I am certain that I will use some of them.

> Are you going to build over the wood strips, or not? I'd suggest you do.
> Your additional cost will be only a few dollars for the wood for the
> chines, and you may be able to recoup most of that in time and materials
> for the fillets -- which you dont have to mess with.

I wasn't going to but now I am planning on it.

> Thomas Hill shows a similar method of building lightweight boats with thin
> plywood over a wood frame in his book on ultralight boatbuilding. It is a
> traditional method.

I have looked at his book and may make a run to the library or bookstore to glean some more insights.

> Assemble your forms and add the long chine and keel strips that define the
> shape of the boat. Lay your lauan sheets on the hull, and use a pencil
> running along the wood strips to mark the lauan for cutting. Cut the lauan
> to the pencil line and it will be a tad oversize. Lay the cut piece over
> the wood strips and screw and glue the panels to the wood strips. When
> they are on, use a plane, router or whatever to trim off the excess from
> the panel. Then repeat this process to glue on another until you have
> covered the hull.

The side panels will come out perfectly sized from this method.

> No holes to drill for stitching together panels, no fillets to do, and no
> hassles with keeping the boat aligned as you wire it up.

I like it.

> You do not need to make scarf joints for joining the panels. You can just
> butt them togetheras you apply them. If you want you can reinforce the
> butt joint on the inside with a layer of fiberglas tape or cloth, or a
> scrap of your 1/8th inch lauan. Stagger the joints around the boat so you
> don't have two lining up. The strength is in the frame, so this is really
> just for looks. It helps to keep the seams from being obvious.

I'll line up the bottom panels with each other and the top panels with each other ala Pygmy. This will give a nice clean appearance.

> You may want to use a plane to rehape the profile of the chines so that
> the panels lay flat on them. Hill has a picture of how he modified a hand
> plane to do this task very easily, but for the little bit you are doing,
> you can eyeball it.

It would be very easy to eyeball it, any imperfections will be easily filled with thickened epoxy when gluing them on.

> In effect you are replacing the 1/4 inch diagonal bridgework with solid,
> 1/8th inch thick sheets of plywood, and using the wood on the bottom to
> maintain the spacing of the bottom strips, instead of using the floor
> pieces for that purpose. No canvas skin is needed. The solid plywood sides
> do double duty.

> Of course, you can cut those floor pieces and install them if you want,
> or, you can just glue and screw a sheet of 1/8 th ply to the floor
> stringers on the inside. You will have a bilge space between the hull and
> the floor, and I'll let you figure out where to make cut outs so you can
> remove water that gets in there. If that floor panel need more support you
> can put a few more slats of wood under it, ( the same thickness as the
> keel and bottom chines) or laminate a 2nd piece of lauan over your floor
> to build it up to 1/4 inch thickness.

I wouldn't put the floor pieces in, they are one of the biggest problems with the Putz design, they really limit the space inside the kayak. I will probably leave the floor stringers in at least the cockpit area for extra strength there.

> You can just tape the seams on the outside with glass tape and resin, and
> paint the thing, or seal the wood with epoxy and varnish it. If you want
> to add glass cloth to the outside, go ahead, but it should not be
> necessary.

I will probably glass the entire thing for extra abrasion resistance on beaches.

> The interior should be get two coats of epoxy resin just for waterproofing
> purposes, but that resin is going to flow into any cracks that might exist
> between your chines and the panels, and improve on your original glue job,
> too.

I wouldn't skip that, but i appretiate you pointing it out for others who may be reading.

> You shouldn't need glass fiber (or any other fiber) reinforcement here,
> either.

> The boat was designed to have the weight and stresses carried by the wood
> frame and trestlework, and it has been around since the 1920's with this
> design. Apparently it works OK. You are keep thing the frame, and
> improving on the trestlework. You shouldn't need the fiberglass for
> strength.

Good point, but it my still be prone to a puncture on the floor. But, 1/8" luan with one coat of 4oz. glass vs. #10 canvas.... The canvas will give more but it is more easily damaged by sharp objects.

> If you don't want to put a layer of glass tape over the outside seams,
> then you can put a layer of 4 ounce cloth on the outside. All it will do
> for you is guarantee an even, continuous, coating of plastic resin. The
> resin must be at least as thick as the cloth to fill the weave, so thinly
> covered areas will be easily visible.

That is my plan.

> You could do a cloth deck, fitting the pieces as for the canvas Walrus, or
> you can make arched deck beams and bend your lauan over them. A little
> epoxy resin for glue, and you can nail, or screw the deck in place. Paint
> the inside of that panel with your 2 coats of waterproofing epoxy before
> it is installed and you won't have to climb inside the boat to do this job
> later !

I will use plywood for the deck. It will look very similar to a Pygmy Queen Charlotte deck, in fact the whole kayak will look a lot like the QC, but will be narrower and have less rocker. Construction methods will be quite different and their design was copied from the West Greenland kayaks which is where Skene got his design for the Walrus (now called a Putz)

> Cockpit coaming, seat, and other rigging I'm sure you will have no problem
> with, after all, this will be your 3rd boat. By now you should have this
> down.

Actually I still have to do a lot of this on my Putz. I am using the Pygmy Thermarest as a backrest and have just the floor slats for a seat, I find it very comfortable, but it needs hip and thigh braces. One of the deck beams is used as a foot brace. I can easily brace against the underside of the deck beams and cockpit with my thighs but it is not too comfortable, I just need some thin padding.

> Keep track of how long it takes to build this, would you.

I'll try.

Thanks again, Mike

Messages In This Thread

3rd kayak
Mike Hanks -- 10/8/1999, 9:18 pm
Re: 3rd kayak
Paul G. Jacobson -- 10/10/1999, 1:47 am
Re: 3rd kayak
Mike Hanks -- 10/10/1999, 11:17 pm
Re: 3rd kayak
Kelly -- 10/11/1999, 10:58 am
Re: 3rd kayak
Mike Hanks -- 10/11/1999, 8:57 pm
Re: 3rd kayak
Paul jacobson -- 10/11/1999, 3:33 pm
Re: 3rd kayak
Mike Hanks -- 10/12/1999, 1:00 am
Re: 3rd kayak
Steve McDonald -- 10/9/1999, 11:46 am
Re: 3rd kayak
Hank -- 10/8/1999, 11:58 pm
Re: 3rd kayak
lee -- 10/8/1999, 10:07 pm
Re: 3rd kayak
Mike Hanks -- 10/8/1999, 11:50 pm
Re: 3rd kayak
Don Beale -- 10/9/1999, 1:26 am