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Re: 3rd kayak
By:Paul G. Jacobson
Date: 10/10/1999, 1:47 am
In Response To: 3rd kayak (Mike Hanks)

> I bought the wood for kayak #3 today. I'm going to use the forms from my
> Putz, but make the bow about 3" higher. I'm doing this one on the
> cheap, using:

> 3 sheets 1/8" luan total amt. $30 for wood. 1 gallon epoxy resin with
> one quart hardener 4-to-1 ratio bought from friend who is a fiberglass
> worker $25. 6 yards 50" 4 oz. fiberglass cloth $35

> I will reinforce inside the cockpit with extra luan. I may use the
> polyester garden cloth on the inside instead of glass, this would be about
> $10 for a 100' roll. Has anyone considered using fiberglass screen
> material on the inside of a kayak? I could use that double thick on the
> inside and it would be less than $10. Any recomendations???

> I'm trying to build it for under $100, and keep the weight below 35 pounds
> hopefully around 30. The deck will be a flat deck except for a peak in
> front of the cockpit, greenland style. It will be 17' long with a 21"
> beam. I already have leftover wire from my Pygmy and the forms from the
> Putz, it seems doable for under $100. I'm also hoping to finish it by
> Christmas to give it to my brother. I'll let my brother worry about the
> varnish.

> I will also be building 2 kid's kayaks for my niece and nephew. Those will
> be from the plans in Roy Underhill's "The Woodwright's Ecclectic
> Workshop". They are very simple skin on frame boats that can be built
> in an afternoon. They are supposed to last about 3 years using the worst
> materials. I'll use better and the kids will outgrow them before they wear
> out. I have enough paint left over from my Putz that I should be able to
> cover 2 small kayaks. I'll epoxy and brass screw the joins instead of
> nailing them. I'll seal the wood which Roy doesn't say to do. I'm also
> thinking about using sythetic cloth instead of canvas. I also have enough
> monel staples left over to use them instead of tacks. All this should make
> them hold up much longer than Roy expects. It will probably take a few
> days instead of an afternoon, but they will be much better kayaks.

> Mike

Mike,

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 !

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.

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

Best regards

Paul G. Jacobson

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