Wood Duck newbie plans-to-plywood questions

Builder's Forum
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I'm a first timer in the preparation stage getting ready to build a 10 foot Wood Duck: I've wrangled junk out of the garage and built a bench, I'm preparing a couple of sawhorses, pulling together the necessary bits and bobs, and last week I got the manual and the full size patterns. First of all I want to thank each one of you who has shared their trials, tricks and tribulations on this forum: the amount of cooperation and goodwill here is amazing and heartening for someone like me who has until now barely picked up a hammer, and I've already learned so much from so many of you I feel a general, huge thank you is called for.


Building from plans rather than from a kit, I'm on an extremely skinny shoestring, but lucky enough to live close to a reputable supplier of the plywood I need. The only snag is that they do not carry the requisite 3mm sapele, so I'm considering 4mm instead, which is as close as they get: this shouldn't be an issue at all since the manual notes you can use 4mm okoume for the deck...should it? (I've read so much about the importance of respecting the bending qualities of different woods)


The builder's manual leaves me wondering if it is better to scarf the 4x8 sheets together before transferring the shapes, or to wait until the longer pieces are cut out and scarf them individually. In the first case it seems easier to line up the pieces and make one long scarf, in the second case it seems like most every example I've seen shows people scarfing the pieces after cutout. What do people recommend?


Also, when addressing the joining of the parts, the manual reminds us to ADD the length of the scarf to one of the two pieces...this sounds simple enough and makes perfect sense, but perhaps I'm overthinking this because I can't visualize how to do it.


Referencing the manual again, on the page concerning transferring the patterns, there is a remark that puzzles me extremely. They write “Included on the patterns are bulkhead and form locations. Transfer these with the awl, but be careful not to cut on those lines!” Can someone explain this? Aren't I transferring the lines in order to cut them?


Of course the purpose of this project is to get myself afloat in a wonderful little boat. But it's also about diving into the unknown and challenging oneself. At the moment though all I can think about is the chance of ignorantly bungling one of these first important steps and ending up with a pretzel shaped boat, or just demolishing several hundred bucks worth of beautiful plywood.

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alrotch,

I'm currently building a wooduck 14 foot (first boat), and a new member to this forum and have found the feedback very useful as well..good folks here!

Regarding the 4mm deck...should be no problem at all, I made my deck out of 4mm Okume..just wet the panels when your stitching in the forms for the bend..I found that to be very helpful with the deck, as well as the stern (when bringing the two sections together there's a good twist needed here..so don't be afraid to hit it with a squirt bottle before bending).

I cut all pieces seperatley and scarfed later..easier to work with the shorted pieces in my shop, but less of a concern with the 10 footer your building. Also, I added two small "alignment" stitch holes where my scarf was going to be when cutting out the pieces..plans call for a 2 1/4" scarf, so I just added two holes in this area (where they overlap) so I could align the pieces when epoxying together...used two small nails to align the sections.

When it refers to adding for the scarf...it assumes a butt joint, and then adding 2 1/4" to one side to accomodate the scarf area. The plans have a bold line (as a butt joint) and then dashed lines showing where each piece would overlap to include the scarf joint...bottom line is, you just need to include an overlap area of 2 1/4" to accomodate the scarf joint WITHOUT changing the overall length of the pieces.

I didn't transfer these lines..they're only for alignment purposes of the temp forms when your stitching (hence NOT a cut line), but I just used the double stitch holes as a guide forlocating the temp forms when stitching.

I'm currently just glassing the inside of the hull, so most of this is still pretty fresh in my mind.

Hope this helps..

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Last part was a little confusing..clarified here:

Regarding:

They write “Included on the patterns are bulkhead and form locations. Transfer these with the awl, but be careful not to cut on those lines!”

I didn't transfer these lines..they're only for alignment purposes of the temp forms when your stitching (hence NOT a cut line), but I just used the double stitch holes for locating the temp forms when stitching.

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Congratulations on taking the dive (hopefully not literally) into a Wood Duck.  I too am building a Wood Duck from plans (a 12 not a 10 though) and had several similar questions after reading the manual even though I built a Shearwater 14 from a kit 2 years ago. 

I am using 4 mm Okume (Lloyds BS 1088) and it's working great.  I couldn't find a source for 3 mm Sapele on the West Coast, and shipping from the East Coast was out of my budget, so I'm cutting it all out of Okume and then plan to laminate some Bubinga veneer over the deck sections (we'll see how that process goes!)  

I decided to join my 2 pieces of plywood before cutting out the patterns so I wouldn't have to worry about trying to line up the pieces later (it was easy with the pre-cut puzzle joints from the kit, but I have read about builders using other kits with butt joints that had problems).  I was in no way up to trying a scarf joint after reading about it, and was worried about getting the length correct, so I decided to just do a butt joint since that is essentially what the puzzle joint is (spread out a bit of course over the puzzle edges), and other boat kit brands (e.g. Pygmy) use butt joints.  It was pretty easy to do the butt joint on the 4 x 8 pices of plywood, I fiberglassed and taped both sides, and have not had any problems of strength on the pieces (I have gotten the entire boat stitched and am waiting for the tack welds to cure at the moment).  

If you want to join the pieces later, you need to add the recommended allowance for the scarf joint (or no allowance if you do a butt joint) when you cut it out - kind of like a seam allowance on a sewing pattern if that helps?  Others can help answer questions about that since I have no experience with it.  

RE:  bulkheads and forms.  Yes, you do cut those out.  (I used tracing paper to transfer my patterns by the way and it worked fine - got a roll of blue stuff at the local art store, 10 feet long x 12 inches wide).  

I cut everything with a jigsaw, just outside the lines, and then used a block plane to bring it back to the line.  I also used the One Ocean Kayak method of cutting out the parts that need double pieces (e.g., hull side, hull bottom, deck side pieces).  You transfer one copy onto the plywood, cut plywood in half diagonally (just wide of the 3 traced patterns), then flip the cut piece and line up the square edges on top of the remaining plywood, hot glue edges, and can cut out duplicate piece all at once.  As recommended, I cut one edge, then drilled the holes and put in a few stitches along that edge to hold it together and then cut the other edge.  It worked great - you get exact mirror images.  Photos and more detail here at One Ocean Kayak site: http://www.oneoceankayaks.com/stitchglue/plyshophtm/platecut5.htm

 At the moment I am trying to figure out what to cut out the coaming spacers from since the manual and parts list didn't say anything about needing 9mm plywood and I've only got the 4mm (would mean cutting 8 (2 sides x 4 high) coaming spacers to get height correct).  Anybody know if you can use non-marine non-Okume for the coaming spacers?  

It will be a fun project.  I had a great time building the Shearwater, and find that things are going so much faster this time (once I figured out the cutting plywood part of course!) 

 

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Nhbuilder, thanks for the reply and the extra perspective, it's quite understandable about the bulkheads and forms now: the funny part is how this understanding answers another question I hadn't quite formed yet, which was how to locate where to wire the bulkhead and forms! I might have spared you that part of the question if I'd had a chance to lay out the drawings and study them but I'm trying to avoid doing that until I actually have the plywood ready, besides which I'm still clearing room in a one car garage and I can't imagine wrangling with those plans in there right now. So thanks for putting that to rest and your simplifying tip about just drilling the stitch holes as a way of marking the right spot.


So here's another question for you, if you have the time. When you transferred the lines to the plywood, did you just line up the sheets and temporarily tack them together, then dismantle and saw them up? The manual recommends using an awl and connecting the lines with a batten of some sort...did you do that, connect the lines freehand, or maybe use tracing paper? I'm thinking one of those flexible curves would be the best way to connect the dots since I don't have much faith in my freehand and tracing paper seems cumbersome and problematic. Anyway, thanks so much for your response and here's wishing you a nice smoothly glassed inside!


KathyD: It occurred to me (after reading a bunch of posts out of the 2500 or so I perused) that someone on this board could probably tell us how much weight is saved by using 3mm sapele instead of 4mm, and that's just the kind of nerd thing I find myself wondering unseriously; I can only guess that's why they specify the thinner stuff, because it's the deck and you can get away with shaving off that much weight. I sorta thought it might be possible it could turn into a problem using thicker sapele when it comes to bending it into that convex shape, but it's not nearly the amount of bending being exerted on 4mm okoume at the bow and stern.


I'm intrigued by the tracing paper idea...it seems cumbersome until I think about your 10 foot piece of it. So did you secure one end of the plans to your plywood atop the tracing paper and then whenever you finished a line just roll up the plans and slide the tracing paper to the next spot? Maybe it's not so cumbersome! But speaking of cumbersome, my biggest question has to do with taping and glue-ing those 4x8 sheets together: how to maneuver the 16 foot piece of plywood around in order to glue and tape both sides?


I really like the idea of the One Ocean method you mentioned, and I think I can see in the manual how they've measured distances from diagonally opposite corners to facilitate this. The savings in time and the idea of ending up with identical pieces makes a lot of sense. But here's one more question for you, which is more of a power tool basic: I've been practicing with the jig saw, and find that no matter what I do, the blade has a tendency to wander away from vertical...do you have any tips or suggestions about this?


Thanks so much for your responses and kind welcomes, it's amazing how a few points of view can help solidify things: I can't wait to get going!


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Trying to cut too fast or with a dull jig saw blade are two causes of blade wander.  If you have an orbital mode on your jig saw, turn it off while cutting out kayak parts unless you are cutting well wide of the line.  The orbital motion speeds up cutting and makes mistakes happen quicker.  The glues in Okoume plywood dull saw blades much faster than plain wood, so check your cutting blade (not down by the tip, up toward the top where the cutting occurs), especially if your cuts begin to smell like burnt wood.  Good luck.

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thanks ootdb! I think you must be right about the orbital mode. I'm going to experiment with that, and slowing down! I'm planning on using metal cutting blades per the recommendations in the manual, and using a couple just to complete the cutouts.

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Plywood weights:

This site has some data on relative weights of plywood:  http://www.boulterplywood.com/MarinePlywood_4.htm

A 4 x 8 sheet of 3 mm Okume is 11 lbs, 4 mm Okume is 12 lbs; 4 mm Sapele is 14 lbs.  So, for the amount of the deck (maybe 1/3 of a sheet?) for the same thickness the Sapele would weigh less than a pound more.  Going to 3 mm Sapele instead of 4 mm Okume for the deck would likely be about the same weight.  One thing I noticed with the Saepele on my Shearwater build is that it seems a bit more brittle and prone to warping compared to the Okume.  Worked fine in the end though. 

Tracing paper:

I got a roll of blue Saral transfer paper, it's 12 feet long by 12.5 inches wide.  I lined up the plans on the plywood (I did not cut them out from the big sheet of paper), taped the sides of the plans with drafting tape, and then slid the transfer paper underneath and traced with a thin pencil (0.7 mm lead) on top.  If the part I was tracing was wider/longer than the transfer paper, I'd just lift one end of the plans at a time, slide the transfer paper over, and re-tape the plans.  It worked fine for me.  I cut a bit wide of the blue lines (at least in most places - there were a few oops) and then trimmed to line with a block plane.  If you use this tecnhique, the issue with the not quite vertical jigsaw won't be a problem because you plane it later (of course you need to hold the plane perpendicular to the sheet, but this isn't rocket science tolerances; mine worked out fine). 

Re:  manuvering a 16 foot x 4 foot piece of joined plywood.  Use 2 people to flip it over.  It really wasn't hard.  As long as your garage is long enough to fit 16 feet of course!  Make sure you put down a plastic tarp to protect the plywood if you've got any oil on the garage floor though, epoxy doesn't like to stick to anything with even small amounts of oil on it.   

 

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Q:"So here's another question for you, if you have the time. When you transferred the lines to the plywood, did you just line up the sheets and temporarily tack them together, then dismantle and saw them up?"

Here's what I did and it worked out very well...

I strayed a bit from the suggested layouts of the parts according to the manual...I took 2 full sheets and put together with the "good" sides outward, then used 6 inch pieces of grey gaff tape to tape around the outside edges, resulting in one sheet of 4x8 plywood, 2 sheets thick.


I then Identified all pieces in which I needed left and right side "mirror" pieces, layed out my full sized plans on the sheet and played with the layout of the pieces so I could get every inch out of the sheet.

I then transfered the lines to the sheet by poking an awl threw the paper template lines about every 2 inches apart, then removed the template and connected the lines using a straight edge and pencil going dot-to-dot.

Don't forget to mark the stitch points as well.

Layout all of your left-right pieces and fit as many as you can on one sheet.

Then, cutting out using a metal blade with the jigsaw, carefully cut out each form, cutting about a 1/16th of an inch outside of the template line.

As you cut out each piece, tape all of those mating pieces together with short pieces of gaff tape around the edges as well..and continue to do all of your final work on the pieces this way. Use a small hand planer (I've had very little experience with a planer before but must tell you, it does a wonderful job of trimming the pieces to the template lines) and plane your edges to the template lines. you'll need to remove the tape pieces when you get to that section of the part, just re-tape when your past it. At this point, I also drilled all of the stitch holes and the temp form and bulkhead stitch holes.

When your done, you've spent half the time and now have two completely symetrical left and right pieces to each part.

Leave them all taped together as any work you do to one will now be identical to both pieces, and when you start stitching up your pieces, you won't have to worry about your boat bowing funny or not being symetrical in any way...it doesn't have a choice of NOT being symetrical if you work on your pieces this way, and it's a whole lot less cutting, trimming, and drilling time if your doing 2 pieces at once.

More than happy to share...ask anytime, and I hope this wasn't confusing.

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NHbuilder, KathyD, thanks. There's nothing like having two different approaches described in such detail to compare to the sometimes sketchy manual. There seem to be so many different solutions to each problem!

 

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RE: material for the cockpit coaming riser

instead of plywood, I used a section of 1x4 cedar (I had some leftover from replacing a couple rotted boards on my house that I just sold). I cut it into 3/4 inch wide blocks (with diagonal\beveled ends as needed, which I pieced together and glued up with epoxy/wood flour  onto the underside of the coaming ring (and used a sheet of plastic, another piece of plywood, and weights to hold it in place while it cured), then used a rasp and some elbow grease to round off the rough edges (though if you were more patient/had more time, you could piece it together more accurately to begin with, but in my case, the "clock was ticking" before the closing date on the aforementioned sold house....),  sanded assertively to smooth it all out, then epoxied the whole assembly onto the cockpit. The key to success with this method is to intentionally go a little "proud" of your final edges when assembling, and then shape it into a smooth oval with a plane, spokeshave, router, rasp, sandpaper, etc. once it is epoxied into position, and fill any gaps with thickened epoxy....and since the "outside" of the curve will be under the cockpit coaming ring, nobody will see them anyway <g>

You could accomplish the same result by painstakingly doing a little "strip build" of the cockpit riser directly onto the cockpit opening.

Julie K.

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Thanks Julie.  I'd thought about perhaps doing the "strip build" type of coaming riser on top of the cockpit opening the other day since I happen to have some extra bead and cove strips laying around.  I figured I could cut a bunch of short 3/4 inch lengths on my Dad's miter saw and piece them together aound the opening.  I'm wondering if I should do 2 strips wide around the opening to support the cockpit rim.  On the traditional strip build method of coaming riser, the uprights get ringed on the outside with other strips to make the rim.  Since the plywood cockpit rim sits on top of the riser on the Wood Duck, one strip wide probably wouldn't be enough to support it. 

The 1 x 4 idea sounds good too.  I recall from my Shearwater build that the plywood risers were not exactly even and needed quite a bit of work to get all the layers smooth on the inside of the cockpit once they were glued up anyway, so maybe I'll experiment with one of the other methods. 

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I'm in the middle of a WD10 so here's my two cents worth as of today with the hull wired and the deck cut out.

I scarfed the sheets together before cutting the parts out. If you look at the part layout in the manual you can cut the two big wedges of ply out so that you end up with a 11' long wedge. No use going all the way to a 16 foot wedge when you only cut out small parts from the very end of the ply. Scarfing is not that difficult I did it with a grinder. I know, I know clam down, it worked and looks OK even to my critical eye. One thing that I did differently is in the location of the scarf. The manual has all the scarfs in the bow, I put the scarf in the bow for the bottom panel then in the stern for the second panel and finally in the bow for the the sheer panel, just looks right to me.

Used the awl to transfer the lines to the ply and then connected the dots with a flexible spline of 1/2 X 1/2 yellow cedar. Made copies of the lines on mylar to check the finished panels and tune up any errors in how fair the lines were. Some of the seams did not line up perfectly when the hull was assembled and required finessing in place with a pull saw. I simply ran the saw along the seam between the panels for a few feet in either direction from the trouble area, eventually with a few passes the panels would come together.

There was no sapele ply around so I stained my deck panels and it looks not bad. Tested the compatibility with the epoxy on a piece of scrap and looks fine, used minwax water based stain and primer.

Defiantly use the water trick for the bow and stern. Don't worry about lining up the bow and stern panels. Once the lower and upper hull panels are wired up I sanded the bow and stern profile true then unwired each just enough to bevel the area in place. When they all looked good wired it up again ready for tack welding. It's tough working between the wires but you can connect the fair points sanded between the wires when you undo the wires for beveling. 

Scarfing the mother panel

hull ready for tack welding

Hope this helps.

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Here's the scarfing jig. Nothing special just some angle iron and flat bar acting as stops for the grinder.

http://www.flickr.com/photos/54523232@N06/6216909945/

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Thanks Rossco, and NHbuilder, and KathyD...so much food for thought!

 

I finally took my titanic penny jar (perhaps I shouldn't call it that) down to my local marine plywood specialty store and loaded the okoume and sapele into a borrowed pickup truck (sandwiched between two sheets of $15 Home Depot exterior grade) for a terrifying-over-every-bump ride home.

 

At this point I became seized, after some horrifying maneuvering-episodes, with a desire to cut this stuff into pieces -hopefully useable ones- as soon as possible. Working in a rather narrow garage (with a low slung overhead door!), as I now realize it is, renders every step a head scratcher. But there is no doubt: this plywood is flexible and its friable, and reacts to humidity like paper. In fact if I could revise this stage I would arrange it so that I could simply start by piling the plywood on a flat giant table: the 2x10' I have will be fine once I get things cut down to size, but the task of scarphing two sheets lengthwise is going to call for some extreme supplementation.

 

For a few reasons, I decided to lay down and rough cut the twice-as-expensive Sapele deck parts first. For one, it allows me to stall while I think about the logistics of that 4x16ish piece; also it gets the sapele out of the way. In a fit of cheapness, I went ahead and pricked the lines onto the wood with my awl instead of getting carbon paper or battens or anything, and connected the lines with a straight edge. I was entranced by the process of watching a fair, curved line take shape as I simply connected the dots. In a purely psychological aside, as well, it was a real milestone to finally start cutting some wood: I found that the jigsaw, at it's slowest setting with a fine toothed metal blade, was very clean and controllable going slow. The sapele dust smelled great, and the cuts looked smooth as butter inside.

 

Now that I have some scraps, I plan to spend tomorrow puzzling out how to orchestrate the alignment and clamping of the big pieces, and to alternate between practicing bevel cutting on my scraps and sharpening my plane irons. I really am not sure how I'm going to make certain that both sheets are exactly square to one another and the joint is both flat and flush, but maybe I'll figure that one out in my sleep!