Idea for rc yachts

Discussion in 'Boat Design' started by chowdan, Mar 9, 2009.

  1. chowdan
    Joined: Jul 2008
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    Location: Seattle WA

    chowdan 1980 PAC41 Liveaboard

    Hey everyone.

    I am going to build a few 1m yachts. Probably 3 or 4. I am most likely going to build it out of fiberglass. I was wondering just thinking differently, what if i screwed all the frames to a piece of wood then super glued 1/8th plywood to the frames to make the shape of hull i want. Then i wrap the hull with something like cellophane or plastic garbage bags, then i fiberglass the hull. Once the fiberglass is dried i can basically "pop" the hull off of the plywood and peal the plastic off and then re-enforce the hull by laying down strips of wood in the bottom and fiberglassing over them to bond them to the hull. Then i was thinking of adding another layer of fiberglass (a very thin layer) to cover over the hull ribs which should create a smooth surface. Then i can add in a dry box which holds all the servos, batteries, and control units. This way it will be super easy to rig quickly, if need be, and also be easy to adjust the sails and all.

    Any input on this idea would be great!
  2. tom28571
    Joined: Dec 2001
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    Location: Oriental, NC

    tom28571 Senior Member

    Unless the boat you want to build is a very simple one with no small radius curves, 1/8 ply will not be easy to work with. I use 1/32 and 1/16 aircraft ply that comes from Aircraft Spruce & Specialty Co.

    It's also difficult to get any plastic sheet to conform to a 3D shape without wrinkles but might be possible. Fairing the model, painting it and then coating with release wax is the usual method of pulling parts from a mold. The key is making sure the release is good whether it's a wax or PVA spray or whatever. Of course the model must shaped so that the hull will pop off without binding on reverse curves or shapes.
  3. Hernandiz
    Joined: Feb 2009
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    Location: Quebec

    Hernandiz Junior Member

    You may also make a plug out of styrofoam ( or anything else ) then make a mold of 2 part silicone. There you will have a easy to pop reusable mold whatever the curve.
  4. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    That two-part RTV silicone is great for small moulds.

    I agree with Tom that 1/16" or 1/32" ply would be called for if you're trying to form curves in this scale.

    How familiar are you, chowdan, with model and/or full size boat construction- would these be your first, or have you built dozens before?
  5. chowdan
    Joined: Jul 2008
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    Location: Seattle WA

    chowdan 1980 PAC41 Liveaboard

    Hey thanks for the replies.

    I am somewhat familiar with building full size boats but have never done models. I normally work on setting up frames and things then someone else comes in and lays the wood and fiberglass.

    I have never built any models. I have plans for several different models but haven't gotten to building them. I like the idea of making a mold from 2 part silicone. I was thinking maybe making 2 hull parts in which it can expand via a screw so you can fiberglass it while expanded then you unscrew them together and pop it out.

    The silicone idea is a much better idea!

    I also had an idea of recycling plastic bottles and using plastic as a hull. In this case I'm going to be using the boats for tourists who really don't pay attention to things and don't care since its not theirs.

    I'm not sure about this but to me it seems like a possible way to build strong, cheap hulls. I'd also be using the 2 part silicone method (thanks to Hernandiz for mentioning it) for shaping the hulls.
  6. apex1

    apex1 Guest

    A very simple and cheap way to achieve a nice surface for such a mold is using "shrinking film" as usual for wrapping yachts prior to shipping. Do┬┤nt forget to apply a release wax or spray, or both.

  7. ecflyer
    Joined: Jan 2009
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    Location: Green Bay, Wisconsin

    ecflyer Junior Member


    I would use the 1mm or 1.5mm 5ply aircraft birch ply for the hull and then laminate a glass cloth with epoxy to strongly adhere to the ply on the outside. The 5 ply plywood will give tremendous strenght to the over-all structure and internal reinforcing would very likely not be needed. If you discovered that you needed more strenght, then add a layer of glass cloth and epoxy to the inside. This method should yeild a lighter stronger hull and faster and easier to build.

    Have a Great Day!
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