COHO 17.5 - building Q&A - Dan's Build

Discussion in 'Boat and Accessory Building' started by Dan_Millsip, Mar 15, 2006.

  1. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    I've just begun construction of a Pygmy Coho -- this is a 17' 6" long by 23" wide touring kayak with a multi-chine hull. This particular kit is a limited edition from Pygmy that is constructed with Sapele plywood -- an African mahogany that is a dark reddish brown colour.

    I'm by no means an experienced kayak builder but I do enjoy building things and have previously built a Pygmy Osprey Double. One of the nice things about building a boat is that you learn so much along the journey -- I anticipate that I'll encounter a few problems and learn just as much building this boat as I did while building the double. I also expect that I'll experience just as many "feel-good" moments as the plywood pieces come together and transform into a beautiful functional boat.

    I won't be following the Pygmy manual to the letter. In fact, in some parts of the process I'll be performing some steps of the construction completely different than suggested in the manual -- such as installing the bulkheads before attaching the deck, and adding custom-made flush deck padeyes.

    I'll be posting photos in our Boat/Accessory Building section of the progress as it occurs -- if you have questions or comments, feel free to post them here in this thread and I'll do my best to give you detailed replies.

    Also, if you are building a kayak (or canoe) of your own and are so inclined, please feel welcome to start your own thread in this forum and share your photos and experiences -- it's this sharing of knowledge that enables all of us building our own kayaks to better our results.

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  2. mick_allen

    mick_allen Paddler & Moderator

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    hey dan,
    what methodology is used to keep the panels aligned when being glued - i notice a few nails sticking up - are they to be all lined up and that keeps the panel pcs in alignment - or are there some reference lines or points that you use say from the edge of the table or a stringline?

    .
     
  3. Peel

    Peel Paddler

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    Hey Dan,
    Looking forward to watching your build and comparing it to mine. I'm sure we'll all learn from each other as we go along (preferrably from our successes rather than our mistakes :oops: )

    Looking at your photos it's interesting that the sapele panels don't appear to be that different from the okoume when they're just raw wood. I've seen a finished sapele model in person when I visited the Pygmy store a few weeks ago, and the color is quite striking - a deep rich brown compared to the okoume. It will be fun to see that color *pop* when you do your first saturation coat.

    Here's to lots of "feel good" moments :D
     
  4. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    Mick, the keel panels are aligned using a straight edge. The remaining panels are then placed together so that the joining edges are tight againsts one another -- basically you're just eyeballing the curve of the panels to ensure that they are placed correctly before gluing. It's quite noticeable if the panels are even the smallest bit out of alignment. From what I've done so far, this method seems OK.

    When I built my double, the method was to snap a bunch of chalk lines and then measure to specific points along the panels to ensure that the panels were aligned. Pygmy stopped doing this as it was a confusing process.

    Pete, the Sapele is only on the outer laminate of the plywood -- the remaining two plys are Okoume. The reason for this is that the Sapele is considerably heavier than Okoume -- using only a single ply dramatically reduces the overall weight of the plywood. What you're seeing in the photos is the Okoume side of the panels. There actually is quite a contrast between the two species even when unsanded and bare -- the Sapele is quite a lot darker than the Okoume. This contrast will no doubt be very apparent in photos of the upcoming steps.

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  5. Peel

    Peel Paddler

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    That's right... I forgot that they did that. Kelly was explaining that to me when I was there, but I seemed to have forgotten it :oops:

    Now that I "remember" this, I recall that the contrast between the outside and inside (as seen at the cockpit, and at the hatches when they are open) is quite striking.
     
  6. SilverDave

    SilverDave Paddler

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    I am about 2 months behind you... Still trying to decide on an Arctic Tern 17 , or the Coho... I think if they offered the 'Tern 17 in Sapele , they would have me.... Sigh ... Is it a LOT nicer than the regular plywood ??... as in... is it worth the extra weight, and the $120 more ??

    . and ohh ........I notice you also live in Langley... cool.. so do I ... well .. half way to Aldergrove (240th) , but still... LOL... LOL... can I come over and kibbitz ? or hold panels together whilst you wire them ? LOL


    SilverDave javascript:emoticon(':wink:')
     
  7. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    It also took me quite a while to make up my mind between the Tern 17 and the Coho -- I ended up deciding on the Coho for a number of reasons -- Mark and Darren had already purchased Tern kits and I wanted to be a bit different. I just like the look of the Coho, and when it came available in Sapele the decision was easy.

    The Coho was $150 US more. I don't know if it's a LOT nicer or if it's worth the additional weight or cost -- but it seemed like a good idea at the time. :wink:

    I'm actually building the boat in Surrey at a friends shop. I don't see a problem if you want to stop by for a chinwag -- PM or e-mail me if you'd like to drop in some time.

    btw: I met a couple from Langley at Granville Island last weekend -- they had a couple of Coho's on their vehicle and said that they had 2 more Coho's in their garage at home!

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  8. drgregarious

    drgregarious New Member

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    Inside Taping

    I have just finished my first Pygmy (an Osprey Standard) and during the process of building this for my wife had a bad case of kayak envy. So here I am now about to start on a Coho!

    I notice that you are using fiberglass taping on the inside only (as suggested in Ted Moore's excellent book) and I am very interested in doing mine that way. Are you using the kit supplied tape or something else? I was considering using bias cut 6 oz fiberglass cloth but am looking for suggestions and if anyone has experience with doing this!

    Cheers.
     
  9. Astoriadave

    Astoriadave Paddler

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    Re: Inside Taping

    When I built my Osp. Std 10 years ago I put the supplied tape on both the outside and the inside and it was not visible. However, I was aggressive in fairing the edges of the tape, and was able to get good wetting so there where no areas of opacity. If you use 6 oz cloth inside, that should be OK. The pieces are flat when butt joined so there is no need to use bias cut material.

    Moores' book is excellent ... I wish it had been around 10 years ago!
     
  10. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    Re: Inside Taping

    Welcome to our site drgregarious. I used the 4 oz. tape that was included with the kit. I figure the 4 oz. tape should be fine so long as I'm not rough-handling the panels.

    As Dave says, bias cut tape isn't necessary as the panels are flat.

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  11. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    Re: Inside Taping

    Dave, I thought that I did a pretty good job of sanding the edges of the tape on my double but I could still see the tape -- and I'd notice it every time that I looked at the boat. That's the reason why I want to omit it on this build.

    I've got Moore's book here as well -- but I haven't had much opportunity to do more than browse through it. I'll be making time to read it over the next days.

    SilverDave, here's a photo of the Sapele with some epoxy that seeped through on the butt joint -- as you can see, it's a very rich dark brown colour. The second photo shows the epoxied Okoume side of the joint for comparison:

    [​IMG]

    [​IMG]

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  12. Astoriadave

    Astoriadave Paddler

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    Dan wrote: Dave, I thought that I did a pretty good job of sanding the edges of the tape on my double but I could still see the tape -- and I'd notice it every time that I looked at the boat. That's the reason why I want to omit it on this build.

    Been so long ago I built that boat, I don't recall exactly how I did the tape on the butt joint. However, I believe I never sanded the tape/wood interface. I used a sharp cabinet scraper, I think, which avoids getting sanding dust into the weave. And, always scraped from the glass/epoxy onto the wood. I really like scrapers for working epoxy ... and always try to catch it slightly green for easy scraping.

    In other areas of the boat, I got some air trapped in the glass (and did not get full wet out) because I was working in a cold shop ... so it had spots where the glass was visible, anyway.

    And, even though you could not see the tape itself, you could tell it was there because of a slight difference in hue (it was a little darker from the extra glass).

    Leaving it off sounds better to me. The joint is only vulnerable until the panels are joined; then it is not subject to rupture.
     
  13. Mark_Schilling

    Mark_Schilling Paddler

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    I've noticed that areas with more glass cloth show as being slightly 'green' compared to the rest of the boat. Even though I was meticulous about smoothing the epoxy, the area in the cockpit that has 3 extra layers over the butt joint is very noticable and quite a greenish colour compared to surrounding areas. I was also very careful about making sure the area where the glass cloth from the deck overlaps the hull by an inch, was well sanded and smooth to the feel. After sanding (but before applying the finish) this area looked just like any other on the boat, but now that it's near the finished stage, it's quite easy to see the 1" overlap. You can't feel it - everything is very smooth - but there's just a slight difference in hue that makes it stand out. I'm not sure what I could have done differently to avoid this though...
     
  14. Astoriadave

    Astoriadave Paddler

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    Nothin', bro. The glass has a slightly different index of refraction than the resin, and every time light has to pass through a glass/resin boundary, the colors separate a little, and some of the red end is absorbed, leaving a very slight green tint. I think that is one reason most of the Pygmy-factory-built boats I have seen have a strip of black tape over the sheer line.
     
  15. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    Although it doesn't show a lot -- the tape is still visible no matter how well you sand the edges. I know I didn't have any dust in the epoxy, so that's not the reason. I think it's just the nature of the glass -- if you look closely, you'll see it.

    I haven't noticed the "green tint" that you guys are talking about.

    Mark mentions the overlap of the glass on the deck being visible -- I anticipated that this would be the case when I ordered my kit and ordered an additional piece of fiberglass so that I could do the deck with one continuous piece of glass -- with no seam.

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  16. Mark_Schilling

    Mark_Schilling Paddler

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    Actually, the overlap on the deck isn't visible at all. What I was referring to was the 1" overlap of the deck glass down below the sheer, on the hull. I imagine that this is more visible because of all the fill coats already present on the hull before this extra layer of cloth was applied. I don't recall seeing this on your double, although I have noticed it on other Pygmy boats I've seen. Not sure why it's so noticable on mine... maybe I just notice it more on my own boat, but I think it's more obvious than on other boats out there.
     
  17. stuart

    stuart Paddler

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    Hey gang, I'm glad I found you. I got a Coho 17 still in the box since UPS delivered it last June. I'm selling the business I have it stored at and figure I better get to it and build the thing while I still have 3000 sq ft of shop to use.

    I'm a bit intimidated at the process, thus the procastination so far. Can any one tell me about the book from Ted Moore you have mentioned? What expertise does it offer and where can I find a copy of it?

    Thanks in advance for your advice.

    Stuart
     
  18. Dan_Millsip

    Dan_Millsip Paddler & Admin

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    Sorry, I misunderstood which seam you were referring to.

    The shear seam is not very visible on my boat but it's definitely there if you're looking directly at it. I find that when the boat is indoors under artificial light that the edge of the glass is much more visible than when it's in natural light. Once you get your boat outside Mark, you probably won't notice it nearly as much.

    You know, all this talk about seams being visible has made me think about a few things -- basically, the seams aren't very visible. The only reason that we see them so predominently is because we built the darned thing and have examined every square centimeter of the boat's surface many times over. Most people don't notice any of the butt seams, the shear seams, or any other little imperfections. What they do see, is a beautiful handcrafted kayak.

    I recall Mick telling me one day while paddling alongside me that he'd never noticed the holes on the deck from the stitches before -- and he'd paddled alongside the boat many, many times previous to that day.

    And in the end, after a while of paddling the boat, you won't seem to notice the imperfections as much either. You get to a point where you just enjoy the boat. And after all, it is a boat before it's a piece of art.

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  19. drgregarious

    drgregarious New Member

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    Book reference

    the book is "Kayaks You Can Build: An Illustrated Guide To Plywood Construction" and is co-authored by Ted Moores and Greg Rössel and I think is an excellent reference. They do a step by step build of 3 boats, one of which is the Coho and in addition have a lot of good ideas about all aspects of building and clean building (ie the laziest way to get a good result)! I have found this book locally at several Barnes and Noble and Powells. Amazon has it for $22.
    His other books look good as well, on strip build Canoes and Kayaks though I havent read either cover to cover!
     
  20. Astoriadave

    Astoriadave Paddler

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    Re: Book reference

    Buddy of mine across the river used Moores' book during his Coho build, and raved about it. Lots of tricks and tips in it. The buddy is one of those very fastidious, fussy guys, so if he liked it, it must be good. Photos are really good.