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    Minimizing weight in my next build.

    Hello boat builders (and everyone else too).

    I'm planning to build another boat later this winter.
    I'm going to build a second version of the last boat that I build (knock off of a Sawyer Shockwave).

    I have a set of forms that someone lifted off of an old Shockwave. I built this boat winter before last and ran it in that years MR340 ultra marathon. The boat came out great and ended up being a good racing and tripping boat. I finished that year's 340 mile race in a little over 57 hours so obviously, I'd did a good job.

    That boat was my first build and I used pretty standard (maybe outdated) cedar strip building methods. 1/4" cedar, 1 layer 6 oz glass outside, 1 layer 4 oz glass inside with an additional rectangle of 4 oz glass where the paddler sits, (plus a few feet forward and back), stemless, ash gunnels and small decks. I also added an adjustable, sliding seat since that's what the original Shockwave's had.

    Like I said, turned out great but weights about the same as a factory goldenglass Shockwave, about 47 pounds.

    I'm looking for suggestions on reducing the weight of this next build substantialy and I was hoping to hear what others are doing that's reduced weight of their builds. I'd be very interested to hear what's worked and what hasn't.

    Since I'm asking questions. Has anyone tried building a strip form and glassing it - then stripping the strips out and adding an additional layer of glass or carbon? Would that even work?

    Let's hear what you've got!

    Cheers, John R
    ????

    #2
    Check out some of Jim Dodds builds, you could use you last build as a mold to build a handmade composite canoe without the work of building a stripper and then stripping it out.
    Not all who are lost wish to be found..............

    Comment


      #3
      Wow, great idea BWCA66. I never thought about using the first boat as a mold for the second boat. That would be a huge time saver for sure.

      Any suggestions on resources that I could check out for information about how to do something like that?

      I was planning to make some improvements/changest the original the original hull but this is definitely worth looking into.

      Comment


        #4
        Doing a composite boat like Jim Dodd and other builders here on canoetripping is one way to go, but you can also save a significant amount of weight by using thinner strips, lighter fiberglass and lighter wood or composite materials for gunwales, thwarts and seats. Browse through building threads on this site. People are always experimenting with a wide variety of approaches.

        Mark

        Comment


          #5
          There are quite afew composite builds on this site, if you look under PaddleCraft Construction .... you can also check out this link http://buildersforum.bearmountainboa...2244&start=105 ... Randy's builds are awesome and I always learn something reading them ...

          Brian

          Comment


            #6
            Mark, I am planning my next build, which is planned to be a 15' Solo at 30#s or less ... I just went through the weight inventory and using a lighter glass is one of the items you may not want to do as it significantly impacts the final structural strength, most of the other items seem to have only marginal impacts. So that one item may not be so viable if you don't want have to baby the boat.

            Brian

            Comment


              #7
              Both Greg and Mark are giving good advise.

              A link to my last composite. Composites are more spendy though.

              http://www.canoetripping.net/forums/...ar-black-pearl

              If you are not going to change the shape of the hull, I'd go with using your stripper as a mold. First off, it should save you time, and weight if done correctly.

              I don't know how you trimmed your hull, but that is an area to save weight also.

              Instead of using a foam core, I used 1/8" cedar, and stripped up an insert. That was roughly the shape of the football. Having the forms will make it easy to make the insert.

              another link

              http://www.canoetripping.net/forums/...he-kevlar-plug

              Using S-glass will ad a little stiffness, over E-glass at the same weight.

              Using partial layers of cloth will save a lot, but put them on the inside, after you have the hull off the forms.

              I'm excited to hear of another possible build !

              Feel free to to ask questions ! I'm sure others will offer advise. You can pick and choose.

              Muddyfeet did an absolute AWESOME composite build, far ahead of mine !

              http://www.canoetripping.net/forums/...anoe-composite

              Thanks John, for starting another build thread !

              Jim
              Last edited by Jim Dodd; 12-11-2019, 05:05 PM.
              Keep your paddle wet, and your seat dry !

              Comment


                #8
                Originally posted by Cruiser View Post
                Mark, I am planning my next build, which is planned to be a 15' Solo at 30#s or less ... I just went through the weight inventory and using a lighter glass is one of the items you may not want to do as it significantly impacts the final structural strength, most of the other items seem to have only marginal impacts. So that one item may not be so viable if you don't want have to baby the boat.

                Brian
                HI Brian. I agree that simply using a lighter weight glass could compromise the structure, but as Jim suggested, using the glass where it counts is important as well as the type of glass. On my last tandem build I used 3.5 oz e glass inside and out with a partial of 4 oz s glass on the outside. I built another identical canoe late last year using 6 oz inside and out. Judging from the hull flex, I think the one using the lighter glass is slightly more rigid and I also think the s glass provides more abrasion resistance. I didn't weigh the two hulls, but just from resin usage i know mine is a little lighter. If you've had the opportunity to wet out 4 vs 6 oz glass you'll know how much less resin you end up using.

                With a solo canoe, especially one with a slightlymore rounded bottom, I wonder if you could use something like 2.3oz glass inside and out, as long as you put s glass on the football. If the bottom had too much flex, then just lay another partial of the 2.3 on the inside. I don't think you need heavier glass on the hull above the bilge.

                Just some of my thoughts, I'll let you know if I ever build that canoe

                Mark

                Comment


                  #9
                  I built a DY Special that weighed 32 lbs
                  3.25 oz glass and 3/16 cedar
                  I’m on the road now but have a little bit of insight for you
                  See stripperguy's photos

                  Comment


                    #10
                    Quite a few people here will give you better advice than I can on what to do to minimize weight for a strip built canoe. But having overshot my target weight on my last (and first) build by about 25 percent (what could have been a 30ish pound, 15 footer now looks likely to be 38 pounds or so), I do have some experience on what NOT to do that I can share. Mostly, it boils down to once you have a lightweight plan, don't diverge from it - no one thing will get you the significantly light weight you are after, so you have to make sure you stick to the lighter option for each and every step/component, or at least don't kid yourself that you can easily make it up somewhere else. I forgot this in a few places - e.g. 6 ounce e-cloth instead of 4 ounce s-cloth because it was available locally, lightweight ash gunnels instead of making composite ones because I was impatient to finish, 4 layers of reinforcement at the stems instead of 2 because ??? - each of which wasn't too significant individually, but added up it made a notable overall increase in weight. Still happy overall, but my take away is that if you want a light build you have to be ruthless in sticking to your plan from start to finish.

                    Comment


                      #11
                      That's great advice traveller. I've done exactly the same thing you describe. Its hard to resist adding small things here and there during the build. Adding some things to make the boat just a little stronger and others out of convenience, or in my case, trying to save a few bucks.

                      Mark

                      Comment


                        #12
                        Yup - it’s pretty easy to get off track here and there, without appreciating the cumulative impact at the end of the day (at least for me). Ozarkpaddler1, if you decide to stay with a a strip build check out the canoe weight calculator at Ashes boats https://ashesstillwaterboats.com/can...ht-calculator/ - doesn’t claim to be 100 percent accurate (although was pretty close for my build at least) but gives a good sense of the impact of many of the general options that are possible for each component of the build.

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