Solid fiberglass stitch & glue

Discussion in 'Fiberglass and Composite Boat Building' started by Bluesphere, Aug 15, 2012.

  1. Bluesphere
    Joined: Aug 2012
    Posts: 2
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    Location: Panama

    Bluesphere New Member

    Okay,
    So I cruise internationally full time and I'm looking for a really durable sailing & rowing pram. I've had it with deflatables and have decided to build a nesting CLC Passagemaker.

    I just ordered my plans and I'm thinking to make solid 4x8 fiberglass sheets and not build it with a wood, foam, or Nida-core hull. I want this to be the last dinghy I ever have. I have a dyer now which is solid glass, light, and durable. It's just a bit too small for my apication.

    Has anyone here ever built a solid glass stitch & glue boat?

    Cheers

    -alex
     
  2. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    I think it would work... However, it would be pretty heavy, something that will make launching and retrieving more difficult. Also, that perfectly smooth surface achievable by that method will still have to be faired with the taped chines and it's a shame to lose that glassy surface.
    You'll need to make a long and wide table to make the panels.
    A plywood hull built the same way would be far stiffer and lighter for the same strength. Plywood will cost more especially if you use epoxy (not needed with fg panels), but I don't think it's so much as to warrant reinventing the wheel.
    glass alone works better when the material curves in two directions (it's why eggs are shaped that way). Thin flat fg panels oil-can far more easily so they must be much thicker to attain enough stiffness. A modified method could be to make panels over a three dimensional mold but there's enough work in setting that up that you might as well go all the way and build a mold for the whole boat.
    I don't think you'll be happy with your glass panel idea in the process of building and also the final product.
     
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  3. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Alan has made the major points.

    The couple of projects I did flat sheet glass construction, turned out very heavy for very poor stiffness.

    If you want a dinghy in glass, you probably need to use a male mould with lots of compound curves and ridges to increase stiffness without crazy weight.
     
  4. Bluesphere
    Joined: Aug 2012
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    Location: Panama

    Bluesphere New Member

    reinventing the wheel

    Tanks for the input guys.

    I was planning to make 4x8 sheets out of epoxy & glass, maybe a layer of Kevlar on the bottom and fairing them with cabosil before I cut the panels so they would be smooth before I stitch and glued?

    I was going to make them as thick as the glass on my dyer dinghy which is not too heavy for what it is, however not so stiff, but acceptable. On the interior bulkhead, seats, and the area where the two halves nest I was going to core with nida-core or foam.

    Here is the boat I want to build:

    http://www.clcboats.com/shop/boats/...emaker-take-apart-dinghy-wooden-boat-kit.html

    At the end of the day I might build the boat out of ply and sell it after pulling a mold off of it but seems like a hell of a lot of work.

    This design really works for me as nested, it would fit perfectly under my mizzen boom for when I do long sea passages. I'm looking for something that sails well, rows well, and is a load carrying workhorse. I'd dont like to burn fuel so wont be using an outboard much.



    Cheers.

    -alex
     
  5. Milehog
    Joined: Aug 2006
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    Location: NW

    Milehog Clever Quip

    You're making it harder than you have to, IMO. The boat is sturdy as is.
    If you must, add a layer of 4 oz. glass to the outside and to the areas on the inside without cloth spec'd in the original plans.
     
  6. Steve W
    Joined: Jul 2004
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    Location: Duluth, Minnesota

    Steve W Senior Member

    You can do a lot of neat stuff with glass, i would make the layup table full length to eliminate the vertical seam in the topside panel and rather than layup 4x8 sheets, layout the panel shapes on the table and create a recess around the perimeter with layers of tape so that when you tape the chines and keel the glass tape will be easier to fair in. If you gelcoat the mold table and use coremat in the laminate you can create an acceptably light and stiff panel a lot easier than other cores for this type of application. If you make your mold table out of melimine faced partical board as used in kitchen cabinets you wont need any type of mold release so of course no residue to remove before prepping the faying surfaces, use polyester products and the materials wont be too expensive and the project will move right along. Dereck Kellsal builds large catamarans this way but of course being bigger projects use foam cores.

    Steve.
     

  7. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Another option is Danny Greens nesting dinghy

    Danny Greene [dtgreene@logic.bm]
    plans for $35

    the design can be seen at

    http://www.duckworksmagazine.com/04/...cham/index.cfm
    http://dory-man.blogspot.com.au/2009/08/chameleon.html

    Steve - what you say has merit, but you are quoting a style of building that gets bent into compound curves at the end, and just reiterating the small point you make at the end of your post - has foam coring.

    I think that if B-Sphere wants total glass, he would be better to knock up the hull using a cheap mdf plug, and take a hull off this, thereby getting the best use of his materials.

    The method he suggests is very expensive and a lot of work, and hasn't even gotten to thinking about the strength of the layup with a layup schedule. There is also no reason to use epoxy. Straight Poly or Vynelester would be plenty good enough for a dinghy.

    Milehogs point is straight down the line - the plans as drawn are plenty tough enough. A 'lifetime dinghy' is just a case of putting in the little bit of maintenance each year.
     
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