Why don't we see more DIY carbon fiber spars?

Discussion in 'Sailboats' started by edik, Oct 30, 2012.

  1. edik
    Joined: Jul 2011
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    edik Junior Member

    I recently saw on youtube how they make carbon fiber masts in a factory. The process didn't strike me as particularly difficult. So, given the superior quality of CF, why don't we see more DIY built mast, booms and other parts?
     
  2. SpiritWolf15x
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    SpiritWolf15x Senior Member

    The factory videos make it "look" easy, it's really a lot more technical and time consuming. You need to know how to lay it up and where and what to reinforce and with what to reinforce with. If it isn't done JUST RIGHT it isn't safe to use. Also carbon fiber is a tad on the expensive side. Simply put, skills and knowledge required aside, the time and expense that goes into making a full carbon spar/boom/spin pole/ect... is just too great for your average boater.

    Aluminum gets the job done, is readily available, easily repairable and isn't anywhere near as expensive.
     
  3. michael pierzga
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    michael pierzga Senior Member

    The engineering of the laminate is important. Also you need a very long shop and substantial tooling..

    If its a small spar, go for it. Google home built carbon spars...dingies...and you will find many people building small spars.
     
  4. Eric Sponberg
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    Eric Sponberg Senior Member

    I second those opinions of SpiritWolf and Michael. I get LOTS of inquiries for designing carbon fiber masts for DIY. Most people simply can't afford both the design and the construction. The laminate has to be designed and tailored to the boat and rig design at hand--there is no such thing as a generic rig. Masts, and particularly carbon fiber ones, are highly engineered structures. The materials are expensive, the process is really not simple--laminating is one thing, laminating correctly is another, and don't forget the post-cure, a must for epoxy laminates. And that is only half the problem--the other half is the fittings: Masthead, gooseneck, heel, shroud and stay attachments, sheaves and blocks--they all have to be designed, engineered, spec'd and built. It all gets complicated and beyond the expertise and budget of most DIYers.

    Eric
     
  5. SpiritWolf15x
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    SpiritWolf15x Senior Member

    Well said Eric.
     
  6. frenette
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    frenette Junior Member

    It's not just a problem with carbon. There are many grades and cloth types some of which are not very acceptable. After you find an affordable carbon/cloth style you still need to pair the glue to it.

    To build a mast at 'home' you need to be willing to build 2 masts. The first mast is test segments so you can define what's lab yield vs what you actually get with the heat/humidity in the shop you'll be working.

    It's really tough to create a recipe for a mast that someone else will build as all these variables create a wide range of usefulness for a rigging part. To pull this off the designer would need to build a number of masts for a given boat design with narrow specifications making this look like you're building an airplane wing.

    The final part of that problem is this is such a small market you don't have a lot of wiggle room for learning from the group of builders. So adding safety margins in the part(s) adds weight making the product less desirable.

    I've built 3 mast in the back yard and the difference in quality, and weight is light years better on every new part. I have plans to build 2 more masts over the next 2 years. I build masts because I want to build masts as it doesn't save money. The time required to get it right is substantial.

    If you like the puzzle to build something like this start building carbon parts. If you can make everything but the mast skin out of carbon you'll get a lot of the effect with less risk to life and limb.

    Dan Frenette
     
  7. michael pierzga
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    michael pierzga Senior Member

    Oh and dont let me discourage you from messing around and building your own spar.

    If its a quarter ton size boat , experiment with a home built, home engineered, carbon boom first. Much easier to envision the loads on a boom and the consequences of failure are small. Lessons will be learned cheaper.
     
  8. Petros
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    Petros Senior Member

    here is a link to pictures of a guy in Finnland who built his own carbon fiber mast.

    www.gust.ax/gallery/mast/

    If you had plans for a carbon fiber mast, that was specifically designed for your applications, and the build-up and details were designed for a home build you could likely build one, but unless there is a large enough demand for exactl that kind of mast, not likely paying to have a professional design it for you would be worth while. Also, as pointed out, the materials are pretty costly and eventually the amount of bad parts you make and junk would eat up any savings.
     

  9. kurtjfred
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    kurtjfred Junior Member

    Hey Edik, if you do your research it isn't that difficult. If you are looking for sweat equity or simply the pursuit of building your own mast/spar from composites, I've seen firsthand what some friends do with composites while constructing their own airplanes. There is a ton of information available, it just that it can be very very time consuming to figure out what you need. There are hundreds if not thousands of experts online that will simply contradict each other all day long, most of the naysayers are of the type whom if everyone listened to, the world would still be flat. Get some published information from the suppliers and vendors such as 3M, aircraft spruce and specialty, etc.. There are lots of books that simplify most of the engineering of spars and beams, especially in aircraft design. It obviously isn't the fastest route, but again, if you simply want to do it for the accomplishment or if you want a carbon fiber mast and want it the cheapest way without stealing it, go for it.
     
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