Thoughts/options for a 14’

Discussion in 'Boatbuilding' started by PROPGUNONE, Jun 19, 2018.

  1. Mr Efficiency
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    Mr Efficiency Senior Member

    So you didn't build and test a prototype, on the water ?
     
  2. PROPGUNONE
    Joined: Jun 2018
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    PROPGUNONE Junior Member

    We did not. Have enough confidence in what the models are telling us that we decided to go ahead and build a few for personal use. Since we wanted at least three and as much as ten we decided this was the best way to go. CAD programs are also pretty incredible at telling you what a model will do.
     
  3. SamSam
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    SamSam Senior Member

    You don't use tooling gel on the actual boat, it's not made for that. It's too brittle for one thing.
    I read through all your sites and I don't understand what you are selling.
    I would expect the designer to supply all the construction details, the order of construction including the layup schedule. In turn you as owner of the rights, would sell plans that show people how to make a finished boat. It sounds like your plans are not actually plans as you can only give the shape of the plug station forms and not even the shape of the finished plug.
    It seems people would have to figure out how to make a plug, then make a plug, figure out how to make a mold from the plug, then make a mold, figure out how to make a boat from the mold and then make a boat, when all people really want to know is how to make the boat.
    Did I miss something?
     
    Last edited: Dec 12, 2018
  4. PROPGUNONE
    Joined: Jun 2018
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    PROPGUNONE Junior Member

    Oh jeez... realized I messed up the question. What it should have said was MOLD schedule, not hull. The hull schedule we have down. More just curious what everyone uses on their own molds.

    As for the plans... yes, in short, you kind of missed something. Or i did a bad job of writing it up, I’ll re-read it. What the plans are for is building a one-off, cold-molded boat. With the use of core material laid over the forms you build the hull, basically just a typical strong-back build. Granted, that version of the boat will be about 1-1.5” bigger in all dimensions, as the male plug forms are now being used as a male mold, increasing size by the thickness of the layup, but the difference is negligible. Never intended to sell plans but had multiple emails asking about it, so I’ve offered them for a short time.
     
  5. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    For the plug, you want it finished to perfection. However you want to have the finished boat look, finish the plug to that level. It is a whole lot easier to work on fairing a convex surface, such as the outside of a bowl, than fairing a concave, inside of a bowl surface. Darker color will show up imperfections much more than a lighter color. That's one reason white is popular on cars and boats, it hides imperfections better.
    Have a lot of fluorescent tube lights around, the reflections will show waviness in the surface. If there is a curve in the plug, the fluorescent tube reflection will be straight curves but it shouldn't be wavy curves.
    Finishing plugs and auto bodywork and painting are almost the same thing, using the same tools and techniques.
    When the mold is taken off the plug, a very light buffing is all it should need to be ready for wax and partall.

    For the mold, some use two layers of tooling gel of different colors, so when making repairs you get a warning before getting into the laminations, which, if not repaired, will always show in a finished piece. Be careful gelcoating sharp inside corners, that they don't fill up with gelcoat or resin. That will leave un-reinforced gelcoat corners on the mold, and the tooling gelcoat being especially brittle, the corners can chip like the edges of window glass.
    The process is to do it slowly, with correct catalyzation and controlled temps and no heavy layups that would exotherm a lot. You want to avoid heat build up or shrinkage or distortions. Let laminations cure overnite or for a day or so before the next laminations. Don't be moving or bumping the plug and mold, or do any vigorous sanding or scraping, especially until a good thickness is built up, as you don't want it to pre-release from the plug in any areas. How much thickness or what it takes to cause problems is a mystery, so just be careful. You need the mold at least 1/4" thick, 3/8" is better.
    The sharp corners mentioned before need to be carefully re-inforced so they don't chip off when demolding multiple boats. You don't want to be repairing molds if at all possible.
    You need positive draft so the piece isn't trapped in the mold.
    If you ever want to vacuum bag or infuse, you need a lip all around for sealing the bag.
    Usually a framework is laminated on the outside to give strength, eliminate distorsion, something to attach wheels to or make it rotisserie like rotatable etc.
    I think isothallic polyester is usually used when making molds for some reasons, ondavar would know about that. It's all I ever used and it would work fine for the boat also. Mat and epoxy are an odd mix and there are some actual advantages in having mat in a layup.
     
  6. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    A cold molded boat is built using epoxy and multiple layers of wood veneers. It ends up like custom formed plywood. What you're talking about is called a foam sandwich build.
     

  7. PROPGUNONE
    Joined: Jun 2018
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    Location: Sharpsburg, GA

    PROPGUNONE Junior Member

    Correct... I have a bad habit of interchanging these two that goes way back....

    The only real sharp corners are along the hard chine, everything else is generally pretty soft, aside from maybe the lower spray rail edges. I’ll reinforce those with extra layers. Draft angles we set to a minimum of five degrees. I like the dual-tone tooling coat idea, hadn’t seen anyone mention that before. Repairing a mold doesn’t sound like a fun process in any way, so a good, heavy lamination is worth the extra time and money. Haven’t decided on the framework yet - I see steel piping common on larger molds. We may utilize that in addition to an OSB lateral frame. The beam is thin enough that we don’t think putting it on a rotisserie is necessary, just a good set of casters to maneuver it with.

    As for resin, I’ve been given as many opinions as there are types. Iso seems to have pretty ideal properties, but I’m also looking at the low-profile resin the FGCI carries. Undecided still on Coremat vs a 1708/1808 build up as well.
     
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