Dave Gentry Chuckanut 12 Build – Part One

by Jim Brown - Sweetwater, Tennessee - USA

Part OnePart Two – Part ThreePart Four

Part 1 – Gettin’ Ready

For the past few years, Carole and I have noticed that our plastic Wilderness Systems Pungo 12 and Pungo 14 had become increasingly difficult to get up on top of our Subaru Forester.  Amazing how those things gain weight over time!  It couldn’t possibly be that we are getting that much older, but maybe at 83 and 77, we might need to consider something lighter to handle.  I had been long intrigued by the various skin-on-frame designs now available, which offer a weight reduction from the 40-something to the 20-something pound range.  Hmmm…

We are strictly flat water recreational paddlers.  There are plenty of good whitewater runs available in this area, but no sense in tempting fate at this point in life.  And as sexy as those sea-going Inuit designs may be, we need something easy to get into and out of, and reasonably stable.  There are lots of lakes and quiet rivers available within 20 miles of here in almost any direction, and although we have an old Harbor Freight utility trailer which could easily handle the kayaks, car-topping would be much preferred, as the trailer is located away from our home, which constitutes an energy barrier – which means the boats would be used less.

We are blessed to have a 3-bay garage, one bay of which is a separate walled off shop, with it’s own overhead door.  I have accumulated or inherited a reasonable assortment of woodworking tools, and it seemed we would have everything we would need for a SOF project.  I had built several boats previously, all of the epoxy and glass on plywood variety, so I felt confident in proceeding.

We studied lots of designs, and decided to build two Dave Gentry’s Chuckanut 12 recreational kayaks, advertized to weigh about 26 pounds when completed.  Since Carole has trouble lifting weights overhead, it will be up to me to get them on top of the Forester, which is pretty high, and I sometimes need a 2-step stool.

I talked with Dave Gentry, and informed him we wanted to build two boats.  The plans were ordered, and we promptly received a packet including a very complete 17-page booklet of instructions, and a set of full-sized frame patterns done on brown Kraft paper with a black Sharpie pen. Since we planned to build two boats, I glued the paper patterns to some scrap 1/4″ oak veneer plywood, and cut them out with a saber saw and an ancient Craftsman 10″ bandsaw inherited from my father-in-law.

One very big problem was that the booklet called for the frames to be cut from 12mm (1/2″) marine plywood, preferrably Okoume.  A local search turned up no marine ply of any kind available in the Knoxville TN area, so I went online and found the closest supplier in coastal NC, about 500 miles from here.  The Okoume was about $110/sheet, but Meranti was available for $80/sheet, which was good news.  The bad news was that it would cost another $80 to have it shipped to a freight station in Knoxville, which was nearly a 100 mile round trip from our house.  But I was filled with enthusiasm, placed the order, and several days later picked up this precious cargo, strapped it to the roof rack on the Forester, and got it home at highway speeds with two straps across, and one lengthwise.

Meranti is somewhat heavier than Okoume, but stronger.  The stronger proved to be a good idea, because later, when bending the stringers around the frames, considerable compression forces were generated!   When I laid out the patterns on the Meranti, I found enough frames for one boat could be squeezed from only 31″ of the sheet.  Hey, I have enough marine ply to build 3 boats!  Since then, I have found a local source for 12mm fir marine ply, which I would use if I had it to do over again.

I also searched locally for the recommended 13′ length of Western Red Cedar, but all I could find at the big-box and lumberyards here was intended as house siding, and was full of knots, and not at all suitable for stringers.  I finally resorted to using the pretty decent looking pine (or mystery white wood) available at the local Lowes, which came in 6′ and 8′ lengths.  Aha, time to dig out the scarphing jig I had made for the Craftsman Table Saw some years ago to produce a nice hollow mast for a Puddle Duck Racer sailboat I was building at the time.  That wood came as 1×4, 1×6, 1×8 and 1×10, so some ripping would be needed before the scarphing.  Once more, I later found a local source for the needed lengths, of WRC or some other woods, at the same place where the marine fir was to be found, which is:  Jeffries Wood Works, (865) 573-5876 in Knoxville TN.  I will investigate that source further for the second boat.

Above is a pic of my rudimentary scarphing jig, made of scrap wood.  A scarph angle of at least 6:1 is recommended.  I think mine is about 10:1, and it makes really good scarph joints.  Note the clamps to hold the workpiece in place, you don’t want to get your fingers too close to that blade.  And stand a little to the left side, in case that machine sends a sharp piece flying in your direction!

Just when you think you have it all together and are ready to do some serious work, stuff happens.  The nice Craftsman Table Saw we had bought when remodeling an NC Beach Cabin we had bought to fix up and flip, had a serious problem.  An unknown someone, at some unknown time, had been working the blade tilt angle mechanism and forced it to the point of bending the mechanism so that the blade angle could not be moved back to vertical.  Several hours were spent investigating the problem, which revealed the saw could be repaired by replacing that entire mechanism, but that would delay the project for at least a month.  The solution was to get on Craigslist and see what was to be had.  I found a smaller, older Craftsman Table Saw for $100, with a new, sharp $40 blade, and I only had to drive 100 miles round-trip to get it.  Not wanting to waste the upcoming weekend and the beautiful Fall shop weather, I got the saw and went to work.  (I have since found the new older saw looks exactly the same as one sold at Harbor Freight for $139, without the mounting stand.  By the time you got a stand, better blade and sales tax, you would be closer to $200.)

The build requires a simple strongback made from a straight, not twisted,  2×4  7′-4″ in length.  I happened to have such a thing on hand!  I mounted this to two plastic saw horses with a couple of deck screws.

The stringers were ripped on the table saw, from the 1xpine.  I have two roller stands, which minimized the number of extra hands required to get these long pieces through the saw straight.  All the stringers are 3/4″x1″, except the gunwales, which are 1-1/2″x3/4 laminated from two 3/4″ square pieces.  The lamination of the gunwales is necessary because the Chuckanut 12 has no rocker in the keel, and the force required to bend the 1-1/2″ gunwales upward to provide some sheer in the deck line would force the keel to hog down at the bow and stern. By installing the bottom half of each gunwale first, and then gluing the top half on later, reduces the force pushing downward on the keel.

Then I scarphed each 6′ long piece to an 8′ piece, to get the proper length after losing nearly a foot due to the scarphs.  The scarphs were glued using TiteBond III wood glue.  After drying overnight, the scarphs were almost undetectable, and withstood great bending forces during later assembly.  Some sanding of the sawn edges was required to get a smoother look, and corners were rounded slightly, especially where the stringers would contact the polyester fabric covering later.  I had purchased a 50-pack of 60 grit sanding discs for my Dewalt Random Orbit Palm Sander, and used most of them on this project.

The frame patterns were arranged on the meranti marine ply for most economical use of the expensive wood.  That’s when I discovered it only took 31″ of the 96″ long 4×8 sheet to get out all the pieces.  Enough marine ply for three boats!

I was not satisfied with the precision of the notches I had cut in the thin ply patterns, so I made an accurate 3/4″ square piece a few inches long, and marked the notches in red pen on the meranti.  I roughed out the various frames with my saber saw, but cut them to the line with the bandsaw.  The cuts for the notches were done partially on the bandsaw (in from the edges), but the bottoms of the notches were done with a coping saw, after first drilling a small 1/8″ hole in the corner of each notch so the coping saw could make the turn.  The notches turned out to be a very good fit to the stringers.

Once again, some equipment problems.  The aforementioned ancient inherited Craftsman bandsaw blade broke just after the frames were completed.  Previously, the rubber tire on the large bottom bandsaw wheel had disintegrated.  I ordered a new set of wheel tires from Sears, but the new tire was so small that there was no way I could stretch it over the wheel, even though I tried heating it with a heat gun, and then in hot water.  Sears was no help in finding out how to get the tire on the wheel.  So I just resorted to running the blade on the bare aluminum wheel, which had worked fine until now.    If anyone knows how to solve this problem please let me know!  Meanwhile, I have a new blade running on the bare aluminum wheel again.

The next step was entirely unnecessary, but I thought it would look better, so I ran both sides of all the frames, and the bow and stern pieces, through my router table with a 1/4″ rounding bit, just to round off the sharp edges, except in the notches where the stringers would be fastened.  That required more sanding, as the meranti didn’t rout as smoothly as some other woods.  The frames were then assembled onto the strongback at the prescribed points.  This is starting to look like the picture of the boat I have in my head!

In this pic, one can see some of the straps used to pull the stringers together at the ends, which took considerable force. More about this in Part 2, where we will start building this boat in earnest.



    the tyme/effort you INVESTED in routing the sharp edges will pay dividends in the finished product

    nicer looking and wont snag as easily

    i might warn you off the fir marine ply since it notoriously has fewer plys and the outer surfaces frequently have football patches in place of surface knots AND the the stuff will check horribly(not much improvement over BCX-YP, IMHO)

    more pics please


  2. Suggest making a steam box out of 4″ PVC pipe.

    Or wrapping the wood with cloth and keeping the whole thing wet, soaked overnight, and using a Spanish windlass to bring the pieces together.

    • Since I don’t really want a 15′ piece of PVC pipe hanging around that will be seldom used, I have been looking at the website that successfully used 6″ diameter 4 mil plastic bags for steam bagging. But the only rolls of such material I have found require ordering on EBay 1500 linear feet at once. Anyone know of source for smaller amounts?

  3. Just finished this exact boat! I used 1/2″ MDO (medium density overlay) for the plywood frames. Nice material to work with and about $65 a 4X8 sheet. A few inner ply gaps had to be filled – luckily none in the critical bonding areas for the stringers. I filled these with thickened epoxy as I glued the stringers up. Need to weigh the hull but am guessing around 30 lbs – and I did an “extended cockpit” with extended floorboards. Have fun with the build!

  4. Can’t find MDO around here that I know of. Just finished the Chuckanut 12, and drafted Part 4 of this series. I enjoyed this build, and look forward to splashing the boat when it warms up a little. Planning my next build now. So many boats, so little time (and money).

  5. I used the 5.2mm underlayment (water resistant, from the wood box stores). Three layers glued with tightbond-3. They have held up for over three years and while I was building the SOF canoe it stayed outside (no cover).
    I used the “three layer” 2’X4′ piece, to cut out my frames. and used the last 2’X4′ piece as part of the floorboards, lashed to the bottom stringers… Click here to get the plans from: http://toledocommunityboathouse.com/plans/willamette/index.htm
    Click here for the Duckworks build story: http://duckworksmagazine.com/13/projects/perseverance/index.htm#.WJ8t039CjNI
    Stephen Ahern (VT)

  6. For the tyre of the bandsaw, perhaps you could find an inner tube for a bicycle and repurpose it. This is field expedient engineering, so no guarantees, just cheap. good luck. BTW, I no longer buy Craftsman as Ifeel the quality and the parts availability have declined from what used to be first-rate.

  7. Thanks for the suggestion on the bandsaw tire. In a subsequent Part 4, not yet published, I got a stronger neighbor to get the tire on the wheel for me. I share your concerns with some of the newer Craftsman power tools. I guess they are trying to compete with Harbor Freight.

  8. Stephen, Thanks for the info on the Willamette Community SOF project. Looks like a fun boat to build. I have just begun a Sawfish foam kayak, to try something new..

  9. I bought a 14 foot clear spruce 2 x 12 at my local lumber yard. (Not a big box store). They ripped all the stringers for me at no charge. I then followed Dave Gentry’s advice on laminating the gunnels and letting the glue dry while they were weighted down between to saw horses by a couple of cans of paint hanging from the laminated gunnels. I am very happy with the results. No scarphing or undue stress on the frames.

  10. Sounds like a good approach. On a next SOF boat, I would at least soak, if not steam the stringers to make them more pliable. The spruce sounds like a good substitute for the western red cedar specified. I have since found a local source for the WRC, but it is not inexpensive.

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