Newbie wohooooo!!!! Need help!!!! 20' Flat bottom River boat

Discussion in 'Fiberglass and Composite Boat Building' started by riverboat_20, Apr 3, 2008.

  1. riverboat_20
    Joined: Apr 2008
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    Location: Carlisle,AR

    riverboat_20 Junior Member

    Thanks everyone for all the info much appreciated. SamSam this sounds like what my uncle had built, instead of building a plug just built a mold, b/c of the simple design. I have looked at the Carolina skiffs I like them something in the j-series is what i want just a lil longer and wider. I can buy clay in bulk cheap and its easy to work with and doesnt dry fast so ill probly use it instead of bondo.

    Here my ?'s


    What kind of fiber glass fabric would you recomend cloth,matt or alternate?

    Thickness of fabric?

    How many layers total thickness?

    What kind of expoxy would you recomend? Here is some Ive found, with a slow cure, which i will probly need.
    https://www.boatdesigns.com/prodinfo.asp?number=09-510

    Would six gallons get me started or would it be to much?

    Is $432.00 a good price for six gallons?

    Should the transome be reinforced with marine wood or stainless steel or somehing besides just fiberglass or just make the fiberglass thick?

    This has been very helpfull thanks ,Randy
     
  2. kengrome
    Joined: Jul 2006
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    Location: Gulf Coast USA

    kengrome Senior Member

    Since you're determined to build a solid glass / plastic boat hull instead of a plywood composite, I applaud you on your choice of epoxy rather than polyester or vinylester resin! The boat you end up with will be both stronger and more water resistant than if you had used the cheaper 'ester resins. You won't be able to gelcoat it of course, but a good paint will protect the hull from UV.

    As far as glass is concerned, just use the type that is compatible with epoxy. Some chopped strand mat is only compatible with 'ester resins because the binders will dissolve only in the styrene that is usually pre-mixed with the 'ester resins ... so be sure to get the right mat for use with epoxy..

    My guess is that you'll use 50-100 gallons of resin before you're finished, so I wouldn't worry about the first (or even the fifth) 6-gallon container. Building high quality plastic boats requires a lot of resin, which is why most builders go for the cheaper polyester / vinylester resins.

    Good luck, and please post pix as you go along so we can follow your progress!
     
  3. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Here is the patent I was referring to...
    http://patft.uspto.gov/netacgi/nph-...50&s1=4495884.PN.&OS=PN/4495884&RS=PN/4495884

    I never used epoxy so you are on your own there.

    In the third reply on this thread is a chart of fiberglass thickness and weights. Click on the chart once to enlarge it, click on it again to make it readable. It is from Ken Hankinsons "Fiberglass Boatbuilding For Amateurs", available at Glen-L.
    http://www.boatdesign.net/forums/showthread.php?t=8686&highlight=fiberglass thickness

    The chart shows typical glass to resin ratios for mat and cloth/woven roving in a regular hand layup, which means no vacuum bagging etc. It shows how much of the weight is glass and how much is resin. If you have a 1000 lb boat made of polyester and cloth, 500 lbs is cloth and 500 is resin. Poly resin is about 9 lbs a gal. so there would be about 55 gals of resin in the boat. Glass is cheaper than resin so if you are using epoxy I would not use mat.

    Layups will depend on how you are constructing the hull. Whether you are using stringers and seats or bulkheads to add strength or if you are using a core. The patent description is based on a 20' hull as an example and gives a number of suggestions as to what a typical layup would be, at least as far as using the described method. Most transoms use 2 layers of 3/4" encapsulated plywood.
     
  4. jermze
    Joined: May 2010
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    Location: boat molding

    jermze Junior Member

    ''jermaine needs help''

    its a pretty cool thing thats going on this web page keep up the good work, I do have a question though what does it mean when you have A concept and then a plug is formed? what materials entails this method?..

    thanks sincerly..
     
  5. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    Have you ever done any fiberglassing? Can you do some carpentry? Do you have some tools and space to build something?
     

  6. jermze
    Joined: May 2010
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    Location: boat molding

    jermze Junior Member

    hey thanks for replying im in the proccess of getting the information i need in order to initiate this objective, but first i need an entry point so i can do the job correctly and get on the right track. ive done my research on the fiberglass and a chemical i can use such as epoxy resin so im on track i just need the right one. now i dont have carpentry skills but im keen as to learn and willing to fiberglass but first, if i buy fiberglass i may not need it untill i make a plug for a mold. What would be one of the first materials i must have to to kick this project off? im curious to know what are the simple methods i need to know about how to build a 15 ft speed boat,? runner foam plug or do i need to make a ply wood plug?, is there any suggestions? and how do i get the correct measurement,? and how to sculp the foam, or ply wood?. what tools i need to get the job done? if that is possible? and also i need more information on how to make a mold for that plug and is it possible,? what do i need? please... thanks....


    thank you sincerly.


    jermaine
     
    Last edited: Jun 11, 2010
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