Inexpensive hull construction materials

Discussion in 'Boat Design' started by fpjeepy05, Dec 9, 2019.

  1. Mr Efficiency
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    Mr Efficiency Senior Member

    Sandwich core materials seem very expensive for the weight in them, you are paying a "bomb" for the trapped bubbles. You need something that can "blow" a cheap recycled plastic.
     
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  2. fallguy
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    fallguy Senior Member

    Oh, good heavens man. The plastic composite would be super heavy vs marine foams. The weight delta is about 7, give or take. The creativity has happened; it just costs more.

    Then, you are forgetting a marketing dynamic. Most people consider a boat, of any kind, a luxury. And very few people in the market for luxury are wild about the go green boat that is heavier.
     
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    Huh ? I am talking about cheaper foam core material, nothing else. Cores are the ideal match to GRP.
     
  4. ondarvr
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    ondarvr Senior Member

    Polyesters don’t bond to the type of plastic you’re talking about, so all you created was a very heavy core ( polyester) with a heavy plastic that is creating a rather weak structure. You didn’t gain much of anything, you may have even lost ground.

    The cost of plastic processed into the correct size and shaped to be used wouldn’t be cheap either.

    I’m not trying to be negative, but all of these this things have been proven not to be effective. Whether it’s cost, weight, strength, toxicity, etc, it comes down to the final cost and performance of the product.

    I’ve worked in China, the cost of labor was nothing, they still couldn’t build a better (or equivalent) mouse trap with cheap materials.

    You yourself need to bring something totally new to the discussion for it to be considered.
     
  5. ondarvr
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    ondarvr Senior Member

    My comment about reed boats was because currently you need to go in a different direction for lower cost materials that will hold up long term.

    From about 1960 to 2000 the small boat market in the US was all about building “CHEAP”. There were many hundreds of boat builders looking for any way to build it cheaper.

    There were some good looking boats, but the build quality was terrible due to inferior and poorly tested products.

    What didn’t work was tossed out (for the most part), what did work was adopted by the better builders. So what we’re looking at now is about 60 years of research into building it cheaper.

    And that’s just the boat building portion of composites, there are many other market segments doing the exact same thing for even longer.
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    I never said anything about a polyester core, my point was that given the amount of material actually used to make the core, the price is in the bubbles ! Obviously if there was a way to make cheaper but effective cores, it would likely have been arrived at, by now, but as we know, technology can change things.
     
  7. ondarvr
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    ondarvr Senior Member

    I was replying to the OP, he wanted to use ground up recycled soda bottles.
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    OK, I wasn't sure who you were replying to there, I guess I was suggesting he invent a way to turn that bottle plastic into a foam product, no doubt a task and a half ! :D
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    I always wondered how they put the bubbles into that Aero chocolate ! :rolleyes:
     
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  10. Rumars
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    Rumars Senior Member

    Yes you need and not only about cement.
    There is a reason nobody uses Bondo stretched with shreded bottles as a core, and balsa is still on the market. Hint, it's not weight in either case.

    Vessel size and purpose is also important. Kayaks can be rotomolded and it can not be done cheaper than that. HDPE can be welded and there are motorboats out of it.
     
  11. Rumars
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    Rumars Senior Member

    Already been solved, every major manufacturer has a "up to 100% recycled" PET foam core in his program.
     
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  12. waikikin
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    waikikin Senior Member

    "It's those bubbles of nothing that make it really something"... Aero (chocolate bar) - Wikipedia https://en.wikipedia.org/wiki/Aero_(chocolate_bar) just for context maybe not everyone Aeros?
    One of the volunteers at my work had shares in and was the manager of an icecream factory, he used to bring some in which was great.... he always said "that air was one of the most profitable ingredients but necessary so the icecream would actually scoop out & we do filter it very very well"

    Jeff
     
  13. Mr Efficiency
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    Mr Efficiency Senior Member

    OK, I will look into the matter, "mirror man" fashion !
     
  14. waikikin
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    waikikin Senior Member

    So, if you ground up old boats into a powder of short glass fibre & resin then added cheap ortho resin to make a paste/slurry added a blowing agent/bicarb/yeast/whatevers cooking then sprayed it into place as a spray core then finished the fibre stack that "could" be cheap as a core/bulker... tick the "green" box too.......
    Personally I'll just continue buying proven off the shelf products regardless of cost perceptions. I've considered a simple concrete block mold as a way to integrate a waste product such as grinding dust into short/sub 600mm retaining wall blocks as I've got some of that to do anyway.
    Jeff.
     

  15. waikikin
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    waikikin Senior Member

    So you're a new romantic?



    Jeff
     
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