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Thread: Mast seal

  1. #1
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    I am restoring a 1967 32' wooden yawl. The wooden mast is keel footed. Where the mast exits the cabin there was a bronze sleeve and probably some kind of boot attached to it. When I bought the boat rain water was kept out thru the use of duct tape. Seems like the hot setup would be to solid mount the mast where it exits the cabin roof so that I can make a good seal. Anyone out there know how the big boys keep the rain water out?
    Gerald Niffenegger
    Florianopolis - SC Brasil

    [ 07-02-2003, 06:46 AM: Message edited by: Gerald ]

  2. #2
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    Originally posted by Gerald:
    I am restoring a 1967 32' wooden yawl. The wooden mast is keel footed. Where the mast exits the cabin there was a bronze sleeve and probably some kind of boot attached to it. When I bought the boat rain water was kept out thru the use of duct tape. Seems like the hot setup would be to solid mount the mast where it exits the cabin roof so that I can make a good seal. Anyone out there know how the big boys keep the rain water out?
    Gerald Niffenegger
    Florianopolis - SC Brasil
    Normally, one uses a canvas 'boot'. It's essentially a truncated conic section. The geometry for the layout is fairly simple -- a little work with a compass, straight-edge and measuring tape ought to do you.

    Plan on stitching on a collar, top and bottom to allow for lashing the boot to the mast and your 'bronze sleeve'.

    The advantage of the mast boot is that it flexs as the mast and the boat move differently with respect to each other.

    Plan on a seam allowance to allow for stitching the canvas into its conic shape.

    By the way...it's important to slip the boot onto the mast [b]prior to[/]b stepping the mast. Just a reminder

    Cheers,

    N.
    --
    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

  3. #3
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    Does the mast pass through the deck or through a coachroof? If through the deck, it is usual to fit (very gently!!) wooden wedges round the mast at deck level. If through a coach roof, a much weaker structure, these are usually omitted.

    I have found that a very much more satisfactory alternative to a canvas mast coat is a mast coat made from a tractor innertube and glued with Avon inflatable dinghy repair cement.

    The mast coat is indeed a conic section, slipped onto the mast upside down before stepping (with the funnel pointing up) - once the mast is in place a tight lashing is passed round the mast coat which is then folded down over the lashing so as to conceal it and secured at the deck.

    The best method of securing it at the deck is to fit it closely over a raised wooden ring round the mast hole and lash it.
    IMAGINES VEL NON FUERINT

  4. #4
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    The mast exits the cabin roof and the previous owner had placed wedges around the mast at the exit point. The exit hole is placed in such a way that it is very strong. I would like to add a picture but am new to this site and have not figured out how to do it?

  5. #5
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    In that case (coachroof strengthened to take the loads) I would go ahead and use wedges. They significantly affect the stiffness of the lower part of the mast.

    DO try really hard to avoid the temptation to bang the wedges in, though!
    IMAGINES VEL NON FUERINT

  6. #6
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    The wedges are crucial. I'm not very good at describing this, but a keel stepped mast is MUCH stiffer for a given mast section than a deck stepped mast; to take advantage of that you need to restrict motino at the deck. Smashing them in with a hammer is bad. Tapping them in with a mallet (lightly!!) is usually good in my experience.

    Here's the example: Take a soda straw and hold the ends between two fingers. if you try to bend it (use your nose, since you're out of fingers), it's quite easy to do. Then add a third point representing the deck, and try again. You'll see it's much more difficult to bend.

    Anyway, the problem with any mast boot is how to stop water running down the mast. a good seal is key. depending on your skill as a sewer, you can consider:

    -Cavnas (traditinoal)
    -Canvas with a rubber or neoprene top. You'll likely need to replace the neoprene seasonally unless you protect it from UV. But assuming your mast is smooth it'll make a better seal than canvas.
    -Rubber. Doesn't look as good but obviously is quite tight.

    I've had luck using a neoprene 'gasket' since it's waterproof, squishy enough to seal, and is available anywhere old wetsuits are to be found [img]smile.gif[/img] You can do it with any of the above options, including canvas.

    I have seen (but never tried) a nice idea for a mast boot, in which a small bendy piece of veneer was wrapped around the mast about a foot or so above the deck, wrapped out to about 1/4 to 3/8 inch, and then the last layer was wrapped a little lower. This created a 'drip edge'... seems if you shoved the top of your boot under that, you'd be damn watertight.
    People who generalize are always incorrect <img border=\"0\" title=\"\" alt=\"[Big Grin]\" src=\"biggrin.gif\" />

  7. #7
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    I have been able to glean enough from all of the posts that I now have a plan for a mast seal. Frers had something in mind when he made the large bronze flange ....... I just don't know what?
    Thanks
    Gerald Niffenegger
    Florianopolis Brasil

  8. #8
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    The flange probably had either a straight vertical profile with a lip (pointing out, away from the mast) or was a concave profile. I've seen a lip more often. Either one will serve to keep the cord at the bottom of the mast boot (the one at deck level) from riding up the mast; mere frictino never seems to work. And once the boot is below the level of the flange, water needs to go down-up-down to get in, so you have fewer leaks. The flange can be permanent, since it's gotta be watertight.

    If you've lost the flange, you can probably make one by laminating together some plywood 'doughnuts' to make a hollow cylinder; make the top doughnut a tad larger in OD to provide the aforementioned lip. Mount the whole shebang to your deck; it'll largely be covered by the boot anyway. Wrap the bottom with veneer for looks if you feel the need.
    People who generalize are always incorrect <img border=\"0\" title=\"\" alt=\"[Big Grin]\" src=\"biggrin.gif\" />

  9. #9
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    Another way of doing the boot is to do a 2-layer boot: the inner layer is rubber or neoprene, the outer layer is sunbrella (UV-resistant acrylic canvas, commonly used for boat covers).

    The best of both worlds.

    The boot is usually lashed to the mast and to the flange with a knot like the</font>Use tarred nylon seine twine (marline) or mason's twine for the constrictors (or tarred hemp marline if you can find it).
    Hope this helps.
    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

  10. #10
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    I think I started this out wrong. I said that I am restoring a 1967 yawl. When I should have said I am putting the boat back in service in almost original condition. The boat was designed by Campos built in the German Frers yard in Argentina. It is a very cool looking 32' yawl.
    Back to the subject. I have never placed a boot on a mast before but I am wondering why in this day and age a person would lash anything with cord? Why wouldn't I use stainless steel clamps and some sealer on the selected material before folding it down over the clamp? Just seem like I would get a much better seal. Maybe not the same as in 1967 but I could live with not quite restored. I have already installed a new 1.9 VW diesel so guess that puts me out of the restored back to original category.
    Thank You
    Gerald Niffenegger
    Florianopolis Brasil

    [ 07-03-2003, 05:27 PM: Message edited by: Gerald ]

  11. #11
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    Originally posted by Gerald:
    I have never placed a boot on a mast before but I am wondering why in this day and age a person would lash anything with cord? Why wouldn't I use stainless steel clamps and some sealer on the selected material before folding it down over the clamp? Just seem like I would get a much better seal.
    If you're dedicated [or burly] enough, you can heave taut the the constrictor sufficient to compress the wood fibers in the mast.

    More importantly, the clamps have sharp edges and ends -- they chafe the fabric and they cut and slash human skin.

    And the lashings...look shipshape, make it Bristol.
    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

  12. #12
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    Picture test
    Gerald Niffenegger
    Florianopolis Brasil

    At the left of this input box I clicked on {UBB Code is enabled} and it opens a blank window that sez WORLD WIDE WEB in the top left corner. When I click on {What is a UBB Code?} I get the same blank window. I clicked on IMAGE but it gave me a window where I had to type the info. in. Any hint as to what might be going on?

    [ 07-03-2003, 09:36 PM: Message edited by: Gerald ]

  13. #13
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    Originally posted by Gerald:
    I have other questions about this boat but need to figure out how to post a picture, before asking the questions.
    Posting an image

    When you go to edit or create a message on the WoodenBoat Forum, just to the left of the multi-line edit box where you type your message is a link cryptically entitled UBB COde is enabled.

    Click on that and you'll get a pop-up window containing the syntax of the markup language supported by the WoodenBoat Forum Software&mdash;quoting, italics, boldface, links, images, etc.

    To add an image to your message, you'll type something like this:

    [ img ]http://www.infopop.com/artwork/footer_logotype.gif[ /img ]

    The embedded spaces in the open/close tags are there so the WBF software won't try to interpret the markup as an inline image. You'll want to omit the embedded spaces betweeh the tag and the enclosing square braces.

    The above markup should show this image:



    Hope this helps.

    N.
    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

  14. #14
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    Picture test
    Gerald Niffenegger
    Florianopolis Brasil

    At the left of this input box I clicked on {UBB Code is enabled} and it opens a blank window that sez WORLD WIDE WEB in the top left corner. When I click on {What is a UBB Code?} I get the same blank window. I clicked on IMAGE but it gave me a window where I had to type the info. in. Any hint as to what might be going on?

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  16. #16
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    Close...but no cigar (American idiom).

    It looks like you have trailing spaces on the url. The [img] markup wants a bare url with the protocol (http specified immediately enclosed by the [img] tags without leading or trailing spaces (It's not a very friendly system, is it?)

    something like this:



    But in retrospect, it looks like the URL you specified isn't an image: it's a link to your ImageStation album:

    http://www.imagestation.com/album/?id=4289773059

    Say...your boat looks pretty sharp (what kind of wood is she decked with?)

    You would not enjoy Nietzsche, sir. He is fundamentally unsound. P.G. Wodehouse (Carry On, Jeeves)

  17. #17
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    Campos, Frers.....she must be a very nice boat.

    But cord lashings have their place - for instance on your guardwires, to break the Faraday Cage - and they are the right way to rig a mast coat. Yes, you can find a stainless steel hose clamp of the requisite diameter, after a deal of searching, and yes it will work just as well, but the effort involved in sourcing such a thing, paying for it, not losing it each year when you lay up, etc is far greater than the effort involved in tying a cord lashing!
    IMAGINES VEL NON FUERINT

  18. #18
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    imghttp://www.imagestation.com/album/?id=4289773059/img

    Here is another try. I found a post that explained it and it states no spaces after img?? Lets see if it works.
    The picture is poor quality because I took it in the evening. The deck is teak but the picture makes it look much lighter than it really is.
    Gerald

  19. #19
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    Well ....... that try didn't work! Nicholas, could you post the exact line of code you entered to make that picture come up? I am starting to think that I am not smart enough to follow instructions so maybe I can learn by example?
    Thanks
    Gerald

  20. #20
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    You've nearly got it.

    The URL should look like this: http://www.imagestation.com/picture/sraid67/p192b39622bc939a02dd883a19c16ac81/fbc61b 90.jpg
    enclosed between the square bracketed [IMG] & [/IMG].

    The above is the actual individual Imagestation image URL that Nicholas and I were able to capture by going to your Imagestation album via the link that you provided;
    Then -
    Point to the image,
    Right click,
    Click on "Properties",
    Highlight the URL,
    Copy (all except the http://)
    Paste it in the box that appears when you use the Instant UBB "Image" Code.
    Click OK,
    Close that window.

    When you think you've got it, click on "Preview Post". If everything is correct, the image should show on your screen, before it is added to the board.

    Nice boat. We expect to see many more pics.



    [ 07-04-2003, 07:39 AM: Message edited by: Paul Scheuer ]

  21. #21
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    [ 07-05-2003, 03:11 AM: Message edited by: Gerald ]

  22. #22
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    We see the dreaded Red X here for the Pacific-PhotoIsland URL. It may be temporarly off. You were close with the Imagestation site, and most of us find that the Sony site is a reliable, if cumbersome and slow, site. Don't give up, it gets easier with every encounter.

  23. #23
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    Xttp://pacific.photoisland.com/sessions/32917658077/18676629lg.jpg

    Here goes nothing./////////////////

    Thanks guys .... I have finally gotten it!
    Would this be considered a trailer sailor?
    Gerald

    How can that be????? Above is the way I posted it except for the Xttp was an http and I had the bracketed IMG etc. When I log into the forum I can see the pictures. Will try the deck picture again.


    [ 07-05-2003, 03:18 AM: Message edited by: Gerald ]

  24. #24
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    Deck picture is there, others are not.

    pacific.photoisland looks to be legit. This water image from one of their public albums shows in my preview.



    [ 07-05-2003, 10:23 AM: Message edited by: Paul Scheuer ]

  25. #25
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    Paul ..... the water picture shows up fine for me. Wonder what is going wrong that I can view the picture on the forum and you can't??? Oh well.
    Back to where this all started. I think .... that I have attached a photo of the mast seal flange. My question is this. The mast is 4.5" X 5.5", hole in cabin roof 6" X 7.25", flange hole 7.5" X 9.5". Seems like a REAL large flange to just hold a pc. of cloth? But then again maybe I am just too lazy to run back to the chrome shop to have it re-chromed?
    Gerald

    [ 07-05-2003, 11:19 AM: Message edited by: Gerald ]

  26. #26
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    Well Gerald, it looks like you've the photo posting solved. I can't help too much with the mast boot, but I'm sure others will.

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