SF Harpoon Scratch Build

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  • elec_tech
    Junior Member
    • Oct 2005
    • 106

    #1

    SF Harpoon Scratch Build

    So here is the fresh start of my second build. I had an unfortunate accident with my first attempt at it so here goes take #2.

    I started again with cutting out the bases for the hull halves with my plans on them. as you know I design my own plans to my imagination so this is something you've never seen before.

    Instead of using balsa for the circle halves I decided to use my 3mm PVC foamboard. It's much stiffer and when you see the pictures you'll see why I did it as well. The set of pictures describes the process accuratly enough, within 15-20 min I had all my circles cut and ready for glueing. I am more impressed with the product I put out tonight than my previous attempt. Go figure huh?

    Here is where I drew on the center lines and 1/8" offset for each base plank. The circles are 1/8" smaller than the outside of the hull to account for the 1/16" balsa plank and the fiberglass layer and filler that will follow. The discs and bases were also marked as to where the measurment was taken and the disc was to be placed. In total, this had 12 discs of varying sizes.


    The Dremel circle cutter tool setup


    I drilled a hole OUTSIDE the diameter I wanted to cut so that I could align the blade. This was important as I wanted the blade edge to trace the outside of the compass line, not the center of the blade. I also predrilled a hole in the center so the disc could spin and be cut.


    Notice how it's cutting cleanly as I described above.


    Finished discs ready for the next step.




    These are the two bases being used for the hull halves.


    Both halves with mounted discs and ready for planking


    This all in about 4 hours work...

    Progress Continues...
  • raalst
    Senior Member
    • Feb 2003
    • 1229

    #2
    nice trick to create the

    nice trick to create the disks !
    what type of cutter did you put in the dremel ?

    Comment

    • elec_tech
      Junior Member
      • Oct 2005
      • 106

      #3
      Ron,

      this is the blade

      Ron,

      this is the blade that I used, It's a dremel all purpose cutting blade.... here in an excerpt from their website on it.

      561 MultiPurpose Cutting Bit
      A high-speed cutter with a 1/8" steel shank ideal for cutting wood, plastic, fiberglass, drywall, laminate, aluminum and vinyl siding.


      Dan




      Edited By elec_tech on 1143914306

      Comment

      • raalst
        Senior Member
        • Feb 2003
        • 1229

        #4
        thanks.
        never seen that before...
        I'll

        thanks.
        never seen that before...
        I'll have a look in the local hardware store for it.
        Might be very handy indeed.

        Comment

        • elec_tech
          Junior Member
          • Oct 2005
          • 106

          #5
          Update]http://img153.imageshack.us/img153/5381/10002242cv.jpg

          planks followed the curves

          Update][/url]

          planks followed the curves much better this time around.




          Nice and consistant half circles... what I like to see!




          The prop fits great!! It'll look smokin!


          That's me...


          Having fun I am... and this one should turn out to be a show stopper...

          Progress continues.....

          Comment

          • elec_tech
            Junior Member
            • Oct 2005
            • 106

            #6
            The Harpoon survived the move

            The Harpoon survived the move better than the Storm so I jumped right back to work on it.

            Progress was focused on spreading the balsa filler around. Not really knowing what I was doing kinda stumped me so I gobbed it on and spread it around to try and fill in all the gaps. I'll try and contour sand it next to get it to the glassing stage. I've noticed some flat spots so I'll try to do what I can. I'm not really good at this so I hope I do it right.





            Over the weekend I sanded down the first layer of balsa filler and added another after securing the two halves together with zip-ties and a bolt through the front sention (where I still have to shape with foam). I still have to glue it together though. I found that the planking has pulled the halves outward due to the tension of the curves on the planks and so from now on the master will have to continue constructionas a single piece. I really have no choice if I want to keep it all symetrical. I gave it a spin though and very few if any wobbles.

            Sorry, no pics of it together yet... later..

            Progress Continues....

            Comment

            • KevinMC
              SubCommittee Member
              • Sep 2005
              • 463

              #7
              Hi Dan,

              Looks like she's coming

              Hi Dan,

              Looks like she's coming along really nicely! If I may offer a tip- when applying filler to a round surface, I would advise using a flexible spreader that can be "bent" to match the contour of the hull. When applying the filler pull it length-wise along the hull (as you have done) but using the curved spreader you should be able to smooth-down the filler in such a way that there are very few "jagged edges" that need to be sanded down.



              How were you going to finish this one? (Did you already say and I've just missed it...)
              Kevin McLeod - OSCAR II driver
              KMc Designs

              Comment

              • elec_tech
                Junior Member
                • Oct 2005
                • 106

                #8
                Thanks Kevin,

                I've been trying to

                Thanks Kevin,

                I've been trying to use a curved tool but in the move I lost some of my smaller ones so I used the one large one I had. Work with what you got I guess. I'm trying to get better at getting the right tools for the job.

                As for finishing the model. I am trying to follow Steves (U812) Blueback thread. All the way from the planking to the fiberglass to the molding. Only now with the plug being in one piece from now on in I might have to follow your thread a little more closely. So getting back on topic, I intend to make a set of molds of it and see if I can take a crack at pulling a hull from them. I might also see about following another route after the mold is made. This is after all just the master.

                I have all the time in the world to work on this as I have no deadlines for completion. I was hoping to get a running version for the August regatta in Oregon but I might just bring the master for show. Who know's how far I'll get by then.

                Thanks again Kevin,
                Dan

                Comment

                • KevinMC
                  SubCommittee Member
                  • Sep 2005
                  • 463

                  #9
                  Having "all the right tools"

                  Having "all the right tools" is certainly a nice thing but knowing when you don't really need a specialized tool, or how to make what you need is even better. The "spreader" in the photo above is actually ~6 business cards all stacked up. Old credit/bank cards also work but on softer, more tightly curved materials I find the cardboard stack to be much more compliant.
                  Kevin McLeod - OSCAR II driver
                  KMc Designs

                  Comment

                  • elec_tech
                    Junior Member
                    • Oct 2005
                    • 106

                    #10
                    Update...

                    Progress at last! and tonnes

                    Update...

                    Progress at last! and tonnes of it! ok lets start from the start of Fridays work.

                    First I sanded down the second coat of balsa filler I applied last time, that brought everything to a nice shap and I am am quite proud of it. I know there are a few imperfections and such but I wanted to move forward and I'll deal with them later. I also glued the two halves together with carpenters glue. pinching the nose together I saw a 1/8" gap at the tail due to warping, I mentioned this before but I figured it was worth mentioning again for clarity. So from this point on the model gets built as a single piece.

                    Next I worked on shaping the nose. I grabbed some of the foam I had left over from shaping the Storm and I 3M 77d it to the vacant nose area. From there it was a matter of sanding it to shape. It didn't come out conical as I had planned... more or less tapered on sides and much more to a point than anticipated. Designs change and I am happy with the result. It almost looks a bit more in touch with the overall effect I was going for.







                    Another thing I did was insert a couple rods in the nose and tail and mount it on a couple brackets. This brought it up off the table and suspended it so I could check for wobble and work towards fiberglassing. My wife caught me on camera playing with the drill and making it spin. I had to... I couldn't help it.





                    Seeing as it was still early in the evening, I decided to move up my weekend plans and glass then instead of Saturday. Following regular procedure then I 3M 77'd the glass to the model. I used whatever I had leftover from the Storm which turned out to be 10oz cloth. I see no problems with it and it turned out just fine. After that I trimmed the seams down and made it so all I had to do was lay resin which went fairly smoothly.







                    I later on laid a nice thick coat of resin glaze over top. The glass was tacky enough for the resin to coat nicely and I think I'll have few issues with bumps and lumps.




                    Edited By elec_tech on 1148242122

                    Comment

                    • elec_tech
                      Junior Member
                      • Oct 2005
                      • 106

                      #11
                      While the glass was tacking

                      While the glass was tacking up I started working on the deck portion. I bought some balsa blocks a couple days ago just for this. Also, before I moved to Vancouver my father gave me his scroll saw to take with me. I was stunned but he thought nothing of it. That said, cutting out the deck was fairly easily. I laid the plans out on the top and the side of the block. This allowed me to cut the plan view and the side view of the deck out. As the deck curves with the hull it was a litle challenging but I got it and it looks pretty good. It still needs a lot of work but for being just cut out that's to be expected. I also test fitted it on the still tacky hull. I couldn't wait to see what it would look like and I think it will add a lot.









                      That's it for today but I expect the next few days I will be able to work a bit more. It's a long weekend here in Canada so Monday is going to be nice to have to myself.

                      Progress Continues.....

                      Comment

                      • mike byers
                        SubCommittee Member
                        • May 2003
                        • 103

                        #12
                        I love your use of

                        I love your use of shelf brackets!
                        Brilliant!

                        Comment

                        • elec_tech
                          Junior Member
                          • Oct 2005
                          • 106

                          #13
                          Thanks Mike,

                          I was quite

                          Thanks Mike,

                          I was quite proud of myself for that one. They we're just sitting in the closet and I thought HEY! YEAH! That would work... and it did...

                          Not as much progress as hoped for this weekend. I decided to spend the time with the wife instead. Great trade I thought!

                          Anyway, I managed to get the glass rough sanded and bondo glazed applied. Next step is sanding down the bondo till smooth and priming for spot filling. I'll get to it when I do. I'm taking my time and enjoying it rather than rushing. it feels better that way.





                          Progress continues....

                          Comment

                          • elec_tech
                            Junior Member
                            • Oct 2005
                            • 106

                            #14
                            Update]



                            Edited By elec_tech on 1148657858

                            [color=#000000]Update]



                            Edited By elec_tech on 1148657858

                            Comment

                            • elec_tech
                              Junior Member
                              • Oct 2005
                              • 106

                              #15
                              Update]http://www.subcommittee.com/forum/icon_cool.gif

                              http://img68.imageshack.us/img68/9808/10003580qn.jpg

                              http://img68.imageshack.us/img68/1051/10003598fe.jpg

                              Progress continues.....

                              Update]http://www.subcommittee.com/forum/icon_cool.gif[/img]





                              Progress continues.....

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