Cost to produce hull molds?

Discussion in 'Boat Design' started by Bullshipper, Jul 16, 2014.

  1. Russ Kaiser
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    Russ Kaiser Exuberant Amateur

    I would be leery of farming out work to China unless I saw examples of their output. In my line of work we have submitted bid packages for the manufacture of process specific equipment to Chinese firms only to find out that they really don't know what they're making. They expect the bidder to detail every aspect of the manufacture process because in reality they're duplicating an existing piece of equipment, not engineering or refining it. Then there is shipping!

    There is a lot of expertise in the Carolinas for making fiberglass boats. If you're going into the boat building business, why skimp on the mold, it's cost is going to be spread over multiple units.
     
  2. Bullshipper
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    Bullshipper Bullshipper

    I agree. But since the plug/hull really has to be tested and modified prior to building the perfect structure, I am looking for a more rasonable startup.

    I am also wondering about the cost of getting the frames and panels developed in rhino from my cad drawings to that I can cnc cut and assemble with stitch and glue.as opposed to ordering a plug or might be another option, as well as producing the plug myself using plywood over frames instead of the more costly and stiffer airtex panel, for stage one.

    This all assumes that plywood is a lot cheaper than other core materials, and that my labor is also up to the task.
     
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    This boat lends itself to alloy construction, being simple curved. Would that be a possible alternative to moulded glass ?
     
  4. Bullshipper
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    Bullshipper Bullshipper

    no,
    too much welding, very slow to produce, Al material is also more expensive, has large drops in net weight even after nesting, and market likes prettier and more maintenance free composites.
     
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    Well, if the labour you are using to make the plug/prototype are up to that job, they should be able to make the mould, the former seems to me to be the harder job. Anyhow, it can wait till it passes sea trials ( being mindful that a glass hull is likely to be heavier).
     
  6. Hoodling
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    Hoodling New Member

    I haven't seen a reply to SamSam's question as to how many boats you want to build - just a few or hundreds. If just a few, then go aluminium after building your plywood prototype. Remember, if it can built in plywood, it can be built in aluminium. And with the right builder, you'll get quality and finish.

    Going the aluminium route will also give you the freedom to make changes that may become apparent or desirable over time - either from a performance perspective or what your potential clients are looking for.

    Going the route of prototype (Mr. Efficiency's good suggestion for testing on the water), plug and then moulds is going to cost a fortune in upfront investment, even if you use the prototype as the plug. And if you're not going to get the sales from at the very least several dozen of boats (SamSam's hundreds potentially), the project will collapse.

    Been there done that in South Africa, British Columbia and the United Kingdom over a period of thirty five years with both monohulls and power catamarans. Cats are my favourites now.

    Wishing all the success with your endeavour.
     
  7. Eric Sponberg
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    Eric Sponberg Senior Member

    The $225K sounds about right for a quality built plug and mold. My ballpark target guess would have been $250K - $300K.

    If you have good-quality 2D CAD drawings and a quality lines plan, you may be able to develop construction patterns directly from those. Going to 3D surface modelling will assist in calculating hydrostatics and stability, as well as making plating patterns for the hull and deck if you wish. Presumably, you have done engineering to determine the scantlings for the structure, or is that yet to be done? The scantlings will determine the final geometry of the patterns.

    Regarding the production numbers, if you do intend to sell a lot of boats, then fiberglass female molds is the way to go. If you want to sell only a few dozen perhaps, then you might want to consider making the boats all plywood and timber (wood-epoxy) and develop male tooling and jigs accordingly.

    Eric
     
  8. Bullshipper
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    Bullshipper Bullshipper

    The idea is to sell the hulls, but their numbers depend on sales.
    I can see why lots of companies just splash used hulls.

    Thank you all for your thougthfull responses.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    Another option you might consider is the C-Flex, duflex, method of construction.
     
  10. Bullshipper
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    Bullshipper Bullshipper

    I'm not familiar with this. Would you have a good link?
     
  11. JSL
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    JSL Senior Member

    A "very rough" ball park estimate we used was the tooling would cost the same as a completed boat
     
  12. Mr Efficiency
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    Mr Efficiency Senior Member

  13. Bullshipper
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    Bullshipper Bullshipper

    Thanks guys. Looked at both cflex and duflex.

    I think I will probably have to modify an existing hull to meet my design requirements if I want to start with less investment.
     
  14. Mr Efficiency
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    Mr Efficiency Senior Member

    Make sure you don't alter an existing hull that is still in production, that would entail a risk of legal action. Then you have to work out why it went out of production, and if it was because it wasn't a viable business proposition. Maybe adding foils could improve an old lapsed design.
     

  15. Bullshipper
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    Bullshipper Bullshipper

    thanks
     
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