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Has anyone used Spartite instead of wedges???

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  • 08 Dec 2015 18:53
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    Reply # 3688358 on 3431475
    Deleted user

    I sail on a Wylie Cat with a carbon fiber unstayed mast that uses a poured  urathane mast wedge.  The owner let the wedge bond to the mast, but greases the tapered hole on deck.  We  unstep the mast frequently to trailer the boat.  Repeated sealing works because the free surfaces are tapered.  If the taper is on the mast side only,  then the wedges need to come free.  On our Freedom the mast is staight and the hole has a very gentle taper.  I cast the wedges in two parts and they come free.  I used butyl rubber to help seal the split. No leaks, knock on urethane.


    Erik 
  • 08 Dec 2015 04:15
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    Reply # 3687028 on 3431475
    Anonymous member

    My 1 success and 2 relative failures might help someone's decision in favour of a poured rubbery 'mast wedge' solution.

    Years ago I stepped the masts with a Devcon 2-pot Shore-80 rubbery goo, poured (with some wood/rubber chunks as volume-fillers) into a big tapered gap (~6cm radially) around each mast. The load distribution and leakproofness were perfect. Success. 

    I did not use a release surface, Failure #1: I had to saw through 7.5cm of tough stuff with a scary saw to unstep the things. I patched up and rebuilt the system using SikaFlex in a pinch, and they worked practically as well as before. No leaks.

    Fewer years ago I duplicated the basic process, but used glass-epoxy instead of rubber to fill the tapered gap, with a release surface - the 'wedge' is part of the mast. Failure #2: The masts creak and move a little, though I thought them immovable, and the mainmast has defeated my carefully-machined-and-prepared SikaFlex-injected gasket idea, which really should have sealed if there were any justice. It took hard sailing to show any problems, as is traditional on boats...

    The rubbery products will apparently seal against a release surface well enough the first time, but I'd be suspicious after a second stepping.

    So, next time...

    Cheers,

    Kurt
  • 07 Dec 2015 18:56
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    Reply # 3686392 on 3431475
    Anonymous member

    I've just stepped my new mizzen mast using www.smooth-on.com Task 9, their strongest polyurethane. The partners are tapered and painted, as smooth and fair as I could make them, and coated with PVA mould release before mast stepping. The mast was cleaned, so that the polyurethane would adhere. 

    At the heel, it was the opposite: the heel plug of the mast is tapered, and was coated with mould release, and the socket into which it fits is parallel-sided and the polyurethane will adhere to it. 
  • 07 Dec 2015 16:50
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    Reply # 3686135 on 3431475
    Anonymous member

    I used Polycraft FC 8000 pourable polyurethane casting rubber, 80 shore hardness. Spartite is 90 shore, and much more expensive. A few rough passages since srepping the masts this summer have not revealed any leaks or other problems.

    My partners are built up of layers of plywood. The tapered mast holes are coated with polyurethane varnish and greased with Vaseline. The poured rubber sealing ring will remain bonded to the mast when it is lifted out to make re-stepping easier than it might be when inserting a parallel tube through a hole of exactly the same diameter.
  • 07 Dec 2015 15:37
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    Reply # 3686039 on 3431475
    Anonymous member (Administrator)

    The first time I saw the use of putty of some kind instead of wedges at the partners, was in Newsletter 31/1996, page 33. The goo used was called polysulfide, two-pot stuff I think.

    Arne

    PS: I have seen a hybrid method in used, on the schooner Samson: The mast was first secured with wedges, and after they had been hammered into position, after some sailing in, the top end of the wedges were cut off flush with the partners. Then a thick (1cm-1.5cm) layer of polyurethane putty was smeared on, holding the wedges lightly together and hindering any rain from entering. No mast jacket needed.

    Samson's foremast partners here:


    Last modified: 07 Dec 2015 15:47 | Anonymous member (Administrator)
  • 07 Dec 2015 09:13
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    Reply # 3678209 on 3431475
    Anonymous member

    Hi Jonny

    Regarding Spartite, I used on my ketch and I can assure you that is a great product, spreads the loads very very evenly and is very easy to apply. That said there are some caveats that you need to be aware of.

    1) The contact area of the mast with Spartite, needs to be VERY WELL GREASED UP AND EVEN ISOLATED WITH A THIN PLASTIC WRAPPER, otherwise the Spartite will attach itself to the mast and you will have to chip it away when you decide to remove it from the boat, do maintenance etc. 

    2)Is really designed to be applied and forgotten and not for folding mast or set ups that require the mast to be often removed.

    That said, I will recommend it without reservations to somebody that will consider the above premises not an issue. I know that I will use it on any and all of my through deck applications.

    cheers
  • 15 Jul 2015 06:48
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    Reply # 3434392 on 3431475
    Anonymous member

    Getting close Jason!

    A fellow Junky suggested a product called Smooth-On ….essentially the same thing as Spartite …but cheaper. AND …. they have a distributor right here in Los Angeles …… if you are interested.
  • 15 Jul 2015 04:33
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    Reply # 3434309 on 3431475
    Deleted user

    When we restep our masts we are going to use Spartite.   At least, that's the current plan.  Can't wait to see you step your mast Jonny!  
  • 15 Jul 2015 04:21
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    Reply # 3434261 on 3431475
    Anonymous member

    Great info! Thanks Peter! I am leaning towards Smooth-on.

    But , for  now , since my motor is not in the boat yet …and will affect trim….I'll just use temporary wood wedges.
  • 14 Jul 2015 22:50
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    Reply # 3433978 on 3431475
    Anonymous

    You will find a lot of information if you go to the following link:

    http://www.freedomyachts.org/search.php?keywords=spartite&sid=9ddc9fe2b64f7d22e513711bbc1a8c42

    Hope this helps.

    Cheers
    Peter
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