Starting a Skiff Company...

Discussion in 'Fiberglass and Composite Boat Building' started by trekker, Apr 18, 2019.

  1. trekker
    Joined: Jan 2016
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    Location: Ohio

    trekker Junior Member

    All, I am in the beginning stages of starting a company producing small skiffs for fishing. I finished up my prototype last fall and get a ton of interest everytime I take it out. The market for boats like mine is wide open with just one other company in the less than $10,000 space. The 17' skiff is made with divinycell foam, epoxy and fiberglass. The proto was built on a jig. I am gonna make a few small adjustments and build a plug and use a mold going forward. I will deal with the gel/epoxy issue soon enough.

    I would love to use this thread to garner advice and knowledge from those in the know. All advice and criticism is welcome. I am aware of the high chance of failure but am gonna give it a go none the less. I dont intend on quiting my job anytime soon.

    My first dilemma is how to ensure positive and level floatation as defined by the US Coast Guard. Is there a method other than filling my boat up with water? I haven't researched the floatation provided by the dcell foam yet. With a hull weight of 200 pounds, I should be pretty good.

    Thanks !
     
  2. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Your boat would likely be positively buoyant, but stable when swamped is another matter. Obviously you have to be guided by what the Coast Guard stipulates as meeting that requirement.
     
  3. DCockey
    Joined: Oct 2009
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    DCockey Senior Member

    "Skiff" is used to describe many different types of boats, including flat bottom row boats and inboard race boats. What does your skiff look like?

    US Coast Guard capacity and floatation requirements for boats under twenty feet in length have several components including engine power rating, capacity rating (weight and number of passengers), and "level" floatation requirements. The floatation requirements depend on the maximum engine power and maximum weight and number of passengers on the capacity plate.

    The amount and placement of floatation required can be determined by someone with sufficient knowledge using suitable software and/or traditional engineering calculations. Information about the requirements and a somewhat simplified method for calculating the amount of foam required and where to place it is available in the Boatbuilder's Handbook. Boatbuilder's Handbook https://uscgboating.org/regulations/boatbuilders-handbook.php Another good source of information is Everything Boat Building aka New Boatbuilders Home Page About New Boatbuilders Home Page http://newboatbuilders.com/pages/about.html Ike, who created the website and occasionally posts here, also sells an e-book on floatation requirements and spreadsheets to help with the calculations. New Boatbuilders Home Page | Ike's Store http://newboatbuilders.com/pages/store.html

    Added: The calculation methods in the Boatbuilder's Handbook and the New Boatbuilder's Home Page do not account for the effects on stability of the core which may be important for level floatation. That effect can be determined using traditional naval architecture calculations or suitable software if the lines of the hull or a CAD model of the hull are available.
     
    Last edited: Apr 19, 2019
  4. DCockey
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    DCockey Senior Member

    If your skiff is rated for outboards it will probably need added floatation aft to support the weight of the engine. Also depending on the shape of the boat and other factors additional floatation may be needed outboard to meet the level floatation requirements.
     
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    Going to be expensive to build with PVC foam and epoxy, do you have a picture of the boat to show ?
     
  6. trekker
    Joined: Jan 2016
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    Location: Ohio

    trekker Junior Member

    You guys are awesome. Thanks for the feedback. Here is a picture. I gave it a pretty narrow width at the transom, so additional floatation there is probably needed. The thought of "stability while swamped" hadn't crossed my mind.

    IMG_20190130_192200_402.jpg
     
  7. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    The "level" floatation requirement which requires a heel angle of 30 (not 10) degrees or less with the passengers sitting to one side and the boat swamped is more difficult to satisfy than the "basic" floatation requirement which requires a designated portion of the boat be above the water when swamped with the passengers centered on the boat.

    Edit: Read the Boat Builder's Handbook and the New Boat Builders Page. The statement above is a simplification of the requirements.
     
    Last edited: Apr 22, 2019
  8. Ike
    Joined: Apr 2006
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    Location: Washington

    Ike Senior Member

    Have you contacted the Coast Guard and gotten a Manufacturer's Identification Code. You will need that to assign Hull Identification Numbers to the boats.
    Call the U S Coast Guard and request a MIC application at 202-372-1052 CWO Kris Franklin Or E-Mail the US Coast Guard at MICapp@uscg.mil This e-mail address is for MIC applications only. Please do not use this e-mail address for general inquiries. For general inquiries call 202-372-1077
    Or write to:

    Commandant
    U.S. Coast Guard
    Chief, Recreational Boating Product Assurance Branch (CG-BSX-23)
    Office of Auxiliary and Boating Safety
    2703 Martin Luther King Jr. Ave, SE

    As for calculating amount of flotation it is relatively straight forward, no rocket science here. David gave you the urls where you can see how to do it. I also discuss placement of the flotation. The most common reason for failing to pass the test is heeling too far. That is all about placement of foam. With an outboard the flotation to support the engine has to be back at the transom and distributed on either side of the boat.

    If you have any questions you can PM me.

    Thanks David. Frankly I have been so busy working on my web site (there have been a lot of regulatory and standards changes recently) updating pages and especially links, that I haven't been here as often as I should. I'm retired, I shouldn't be working so much (LOL)

    PS: why does the government change it's URLs so often??? All those years working for the government and I still haven't figured that one out.
     
  9. trekker
    Joined: Jan 2016
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    trekker Junior Member

    This is something I will have to address. This boat gets pretty narrow toward the stern and is actually quite narrow overall.
     
  10. Ike
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    Ike Senior Member

    Actually it is not the full weight of the passengers. The weight used for the stability test is a one half of the weight for persons (which is only 1/2 of the full persons weight). So really it is only about 1/4 of the weight of persons for the stability test. How much depends on the persons weight for your boat. It depends on whether the persons wight is 550 lbs or less.
     
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  11. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    And I had a mistake in my earlier post (now corrected). The maximum heel angle for the stability test with the off-center load is 3o degrees, not 10 degrees. Consult the Boat Builders Handbook or a reputable source such as the New Boat Builders Page for the details. Don't rely on information from the forum.
     
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  12. KD8NPB
    Joined: Mar 2018
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    Location: South Carolina

    KD8NPB Senior Member

    Why epoxy?
     
  13. trekker
    Joined: Jan 2016
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    trekker Junior Member

    It's what I like. Makes for a light boat. I see a lot of shallow water/flats boats that weigh 4 to 6 hundred pounds.
     
  14. KD8NPB
    Joined: Mar 2018
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    Location: South Carolina

    KD8NPB Senior Member

    Resins weigh about the same. Your laminate schedule dictates weight.

    Epoxy is rarely used in production because of cost, and because of its poor secondary bonding characteristics. Also, in order to deliver maximum properties, most epoxies require a elevated temperature postcure.

    I can achieve most of the same properties as epoxy using a urethane acrylate system that still uses relatively cheap peroxide initiator systems. And I can still use my standard NPG grafted polymer gelcoat with UA resin.

    For a skiff, if you had finite structural analysis done on the design, I doubt your potential stresses would require epoxy.

    For nerd factor in the boat instead of using an ISO/DCPD poly. I would look at using a strong VE blend such as Ashland AME6001 VE/DCPD, or AME6441 for 100% VE.
     

  15. trekker
    Joined: Jan 2016
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    Location: Ohio

    trekker Junior Member

    I get the cost factor. I can build this boat with 11 gallons, so it doesn't add much overall cost compared to the upside.
     
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