carbon masts?

<< First  < Prev   1   2   Next >  Last >> 
  • 09 Aug 2013 22:43
    Reply # 1362157 on 1362108
    Anonymous member (Administrator)
    Ketil Greve wrote:

    Hi,

    I can recommend Rudolf VD Brugs masts as Marie G is equipped with his mast. The best thing with carbonfiber is that it can be designed to the stiffness required. My 12,5 meter mast is really stiff and weighs in at 61 kg! I enjoy it everytime I goes out sailing, as Marie G is a high performing X-99 yacht. I describe it as a big Lazer dinghy with toilet, cooking and sleeping fasilities, easily handled by an old singlehanded sailor. Just ask Arne.

    Regards

    Ketil


    Haha, yes, Ketil, just rub it in!

    I’ve said it before and I repeat it: There is only one fjord flyer in Stavanger and that is Marie G. We met her today when we were out in my new Frøken Sørensen. Despite feeling quite content with our boat, we were sitting ducks compared to Ketil’s X-99. She may well be the fastest monohull junk-rigged sloop in history. Here is a photo I took today (in the JRA photo gallery).

    Cheers, Arne

    PS: 55sqm SA on 2.8 tons boat, combined with fine lines and an efficient keel and rudder - how can that be wrong?

     

    Last modified: 09 Aug 2013 22:49 | Anonymous member (Administrator)
  • 09 Aug 2013 21:15
    Reply # 1362108 on 623036

    Hi,

    I can recommend Rudolf VD Brugs masts as Marie G is equipped with his mast. The best thing with carbonfiber is that it can be designed to the stiffness required. My 12,5 meter mast is really stiff and weighs in at 61 kg! I enjoy it everytime I goes out sailing, as Marie G is a high performing X-99 yacht. I describe it as a big Lazer dinghy with toilet, cooking and sleeping fasilities, easily handled by an old singlehanded sailor. Just ask Arne.

    Regards

    Ketil

  • 09 Aug 2013 14:03
    Reply # 1361836 on 623036
    Cool idea for mixing epoxy. So you wet out the fibre inside the bag before laying? Would the freezer bag method be good for forming epoxy fillets? Thinking on DIY masts, a 12m glassfirbre flagpole is a reasonable price, about £500 (nearly double for a 15m). I was thinking of using the pole as a starter and adding a layer of Carbon. Anyone advise on a supplier for carbon in uk? regards Mark
  • 09 Aug 2013 01:39
    Reply # 1361606 on 623036
    I am going to experiment with birds mouth mast construction and using some carbon fibre tape (strands of fibre) in the process. I have an 11' dinghy for trials. After milling the birds mouth sections I will lay the individual pieces upside down and fasten very straight on a generated I beam out of wood made straight and flat. Taking a router I will dado a groove about 1" wide and 1/4" deep for the length. Will make a plug out of same mast material to tap back into the dado and clamp after laying the carbon fibre strands in the dado. I am wanting to make the mast sections thinner for the process. Laying the carbon fibre in a dado bed with epoxy and clamping a wooden plug back into the dado section, I should get a good bond. 

    Another thought would be to cut an 1/8" groove in the center of the birds mouth about 3/16" deeper and placing the 1" wide strands in that groove. I dont think it would be as stiff using material in this manner as laying full width in the dado. 

    Very carefully roll strands up and place in a freezer zip lock to mix with epoxy. I mix most of my epoxy in freezer  zip locks. Lays flat stays cooler longer. Mixes easier. Clip the corner work it out. Squeegee everything out. Recycle. I will take pictures and keep you posted. Any thoughts or feedback would be appreciated.    Don

  • 22 Jun 2011 09:58
    Reply # 627415 on 626975
    Paul Thompson wrote:
    Rudolf van der Brug wrote:

    I built two rigs to Rob Denney's plans. That included mast (17.5m), boom and everything
    related to get things working.
    Those were carbon masts built following a system Rob thought up.
    Although it worked I would use a different method now, building two halves and joining them together. They would be vacuumed in a mould and post cured ,so very good specifications are possible. If it's up to me I would have them engineered to have them stiff enough. Strenght should be way past what you need in a stiff carbon mast.

    Hi Rudolf,

    Could you fill us in on how you go about building your own carbon masts? Tell us more about Rob Denney's or where one could go to find out. What are the issues with building your own? More information would be most welcome.
    Hi Paul,

    First of all, I am a professional builder and the rigs I mentioned were built for owners.

    The building method of those masts was quite complicated and risky.
    The idea was to end up with a seamless pole. That means you start with a flat piece of cured glass that is laid up with carbon(0 deg.) and more glass(+-45deg.) and then while still wet rolled into a tube using lots of stuff to keep it all under control.
    The soft tube is inflated with a pressure bag inserted at the start of the rolling sequence. The ends are closed with wooden discs, one of which has the air hose through it providing the pressure. Putting the pressure on is the frightening bit.
    If things go well this leaves you with the primary tube. This is covered with more glass and carbon which are rolled around the tube and concequently vacuumed. The masts were post cured at 60degC.

    The masts I built this way are stiff and strong. They are both on Visionarry proas designed by Rob Denney. One is Blind Date, which boat I built entirely, and the other is on ONO, which has a Finnish owner.
    In the meantime I've thinking about different ways to build carbon masts. I would probably
    use a half mold now and vacuum the halves, joining them together later. 

    Building your own carbon mast can be done. But if they are to be of any serious lenght risks are getting bigger. You don't want (too many) air bubbles inside the laminate.
    So you have to use vacuum or pressure, or both to get the air out.
    You need to do tests to try the method, and have samples to check the laminate. 
    If taken seriously it is quite a task. As a job it is a challenge and it keeps you busy thinking of new solutions.
    if you have more questions, please ask
    regards,
    Rudolf


  • 21 Jun 2011 19:59
    Reply # 626975 on 626622
    Rudolf van der Brug wrote:

    I built two rigs to Rob Denney's plans. That included mast (17.5m), boom and everything
    related to get things working.
    Those were carbon masts built following a system Rob thought up.
    Although it worked I would use a different method now, building two halves and joining them together. They would be vacuumed in a mould and post cured ,so very good specifications are possible. If it's up to me I would have them engineered to have them stiff enough. Strenght should be way past what you need in a stiff carbon mast.

    Hi Rudolf,

    Could you fill us in on how you go about building your own carbon masts? Tell us more about Rob Denney's or where one could go to find out. What are the issues with building your own? More information would be most welcome.
  • 21 Jun 2011 12:29
    Reply # 626622 on 624518
    Robert Biegler wrote:Rob Denney makes unstayed carbon masts for his proas.  If I remember correctly, he wrote he can offer an unstayed carbon mast for less than a stayed aluminium mast that would support the same sail area.  I don't know what changes to the price of carbon and aluminium have done to that notion since then.  You can always ask.  Some (pretty minimal) information is here: http://www.harryproa.com/masts_1.htm  The web site hasn't been updated for some time, but I think that is because he no longer has anyone doing that for him, and he is too busy building boats.  You could also ask questions on the harryproa group on yahoo.

    Regards

    Robert Biegler
    Hi Robert,
     nice seeing you are still keeping up with things.

    Prices for alu masts are unknown to me, but I can build carbon masts competitively.
    I built two rigs to Rob Denney's plans. That included mast (17.5m), boom and everything
    related to get things working.
    Those were carbon masts built following a system Rob thought up.
    Although it worked I would use a different method now, building two halves and joining them together. They would be vacuumed in a mould and post cured ,so very good specifications are possible. If it's up to me I would have them engineered to have them stiff enough. Strenght should be way past what you need in a stiff carbon mast.

    regards,
    Rudolf  
  • 18 Jun 2011 15:42
    Reply # 624518 on 623036
    Rob Denney makes unstayed carbon masts for his proas.  If I remember correctly, he wrote he can offer an unstayed carbon mast for less than a stayed aluminium mast that would support the same sail area.  I don't know what changes to the price of carbon and aluminium have done to that notion since then.  You can always ask.  Some (pretty minimal) information is here: http://www.harryproa.com/masts_1.htm  The web site hasn't been updated for some time, but I think that is because he no longer has anyone doing that for him, and he is too busy building boats.  You could also ask questions on the harryproa group on yahoo.

    Regards

    Robert Biegler
  • 17 Jun 2011 15:02
    Reply # 623886 on 623036
    Deleted user
    I'll post that source I thought looked so good after I get home. I'm still on this quest to find the Holy Frail and bring seablossom home and have only my smartphone. It's ok but the real computer is much easier.
  • 17 Jun 2011 03:38
    Reply # 623556 on 623036
    Can you share your sources with us, please, Jeff?
    Certainly fiberglass poles are getting better. These people:
    offer both alloy and fiberglass, and the strength they are quoting for fiberglass poles make them worth looking at. The way that they are making them is sound and sensible, for use as an unstayed mast.
<< First  < Prev   1   2   Next >  Last >> 
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software