Separate Deck From Hull

Discussion in 'Sailboats' started by BobBill, Oct 17, 2009.

  1. BobBill
    Joined: Oct 2009
    Posts: 693
    Likes: 10, Points: 18, Legacy Rep: 157
    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Par, You certainly know your stuff and are extremely helpful. And, though topic is limited in appeal, may help in this project or others.

    I plan to separate the deck from the hull on a small dinghy also, and your comments are greatly appreciated.

    My question concerns how one separates the upper section or decking from the hull at centerboard or dagger board case?

    This boat is a doubled hulled design once popular and produced by Newport Boats (Mobjack, Kite, Pacific Cat) Pics added to clarify boat. Deck is above waterline.

    Am guessing the case is somehow chemically fastened when mated internally.

    And, I was thinking that replacing the foam only at high points, to assure buoyancy if totally swamped...what kind of foam is customarily used?

    Refers to project in thread below here - http://www.boatdesign.net/forums/sailboats/test-experiment-29733.html
     

    Attached Files:

    Last edited: Oct 17, 2009
  2. PAR
    Joined: Nov 2003
    Posts: 18,018
    Likes: 353, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Your boat has a bonded deck cap to hull joint as do many small sailors. Larger craft have a bedded hull to deck joint, typically covered with an aluminum extrusion and hard fastened with sheet metal screws.

    Both joints can be separated, though it's a lot easier to break open a bedded joint then a bonded one.

    Bonded joints have to be carefully cut open. My tool of choice for this is a small air powered jig saw sort of tool. It has a small blade and can be steered very well in confined spaces. The idea is to imagine where the joint is bonded and split the cap from the hull.

    On your boat there's more to it as the dagger case and likely other areas, mast step, transom, etc., will need special attention. How to approach this would be a "open 'er up and have a look" kind of thing. You may be able to use similar techniques from the outside or you may have to wedge the boat open as best as you can then cut from the inside.

    Looking inside the deck access ports with a light and mirror, may show what you're up against. In any event, you'll have to make 'glass repairs from tears, cracks and rips during the process, which is just the nature of this type of work.

    Your attempt with the surface piercing bow isn't going to do much for you on such a bluff entry boat. You need an entirely different entry for this to have any merit.
     
  3. BobBill
    Joined: Oct 2009
    Posts: 693
    Likes: 10, Points: 18, Legacy Rep: 157
    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Separateing Hull from Deck

    Thank-you, Bill. I appreciate your advice and your time.

    It is as I thought. I figured it was bonded, not "butylized."

    As you stated, the joint is covered by aluminum rub rails (late model as former models were teak) with pop rivets. I bought one of those vibrating tools to open the top and will add inspection ports in appropriate areas to spy.

    It was the dagger board case that had caused most concern, and will have to look to see how the maker did it. This boat was made after Brunswick took over and the firm was in trouble, so they did take shortcuts that Newport and Carter Pyle likely frowned upon.

    I will do it in spring and let you know.

    As to the bow. I will likely not go for the dread style, but it is a thought still. I sail in areas of significant chop, so will have to hold off on that one anyway until we get the hull solid. I realize the short hull offers little opportunity for improving the straight line motion, but will leave that to later thoughts.

    Hull first, improve traveler, add longer narrower kick-up rudder, add Force 5 mast, boom and sail to fit into mast chock and step.

    Force 5 sail is larger, so may go to full battens and shorten, with flat head. (Will refinish original mast and boom and set aside; original sail will patch and store - all 1973 mfgr.)


    One thing, What kind of foam is typical for this application. I am guessing the foam, if any, is laid up along hull sides, with open interior stem area for draining the condensation etc.

    Again, I appreciate your advice and your time.

    Bob H.
     
  4. PAR
    Joined: Nov 2003
    Posts: 18,018
    Likes: 353, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    There will be no consideration for draining condensation from the interior of the boat. The foam will be open cell polyurethane or polystyrene or something, who knows, but it's suck up moisture like a sponge. It's arrangement below the deck cap will be equally as haphazard. These two things are common problems with production boats from that era. Others will be reinforcement areas made from wood, that have rotted from the moisture collected between the deck cap and hull shell, (with no place to go). Transoms and under seats are common locations for this as, would be mast steps and other high load spots.
     
  5. BobBill
    Joined: Oct 2009
    Posts: 693
    Likes: 10, Points: 18, Legacy Rep: 157
    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Foam Flotation

    Thanks again.

    So foam is a no-no.

    Any other choice, styro or similar products glued in place; or just leave it and seal it?

    I had thought to put minimal flotation in bow and just forward of transom on each side - styro or some closed cell stuff. Minimal amount.

    Transom on this boat is solid.

    I kind of guessed the foam was a sponge. Did not like idea of redoing old errors, but am limited in knowledge there.

    Bob
     
  6. PAR
    Joined: Nov 2003
    Posts: 18,018
    Likes: 353, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Don't bother replacing the foam. With sealed chambers, they do the same thing and can't absorb moisture, plus they can be drained.
     
  7. BobBill
    Joined: Oct 2009
    Posts: 693
    Likes: 10, Points: 18, Legacy Rep: 157
    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Hull Flotation

    Aye. Leave it and seal it then.

    Thanks.

    One last question. Would you recommend "butylizing" with marine sealer at deck-to-hull joinery or bond it?

    I really do not know how much the two parts contribute to rigidity, but the deck and hull joint is right-angled where they join with what appears to be the snap rivets holding the rub rail through the deck and hull into the void between them..

    Interesting project this.

     
  8. kite sailor
    Joined: Dec 2009
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Boston, MA

    kite sailor Junior Member

    I don't know if this reply is too late or not, but I thought I'd share. I stumbled upon this thread searching for info on the Newport/mobjack Kite. I have one and I am currently restoring it. I separated the deck from the hull in order to do some glass work on the inside to stiffen the hull here is a link to a gallery of photos from the process. There are plenty of shots of the separation. We simply pulled off the rub rail, then pulled out all the rivets joining the deck and hull then used a skill saw to cut through the glass around the entire boat. Then three others and myself lifted the deck off the hull with ease. Some hindsight 20/20 advice though is to cut the deck off from the underside so that when you replace it the deck overlaps the hull. It will be much easier to refasten and seal the two together.

    Also, about the foam inside: As you can see in the pics the foam inside mine was terribly water-logged so we discarded it entirely. We will be replacing it with expanding foam (industrial version of the "Great Stuff" in the spray can you can buy at the hardware store). I'm told, and it makes sense to me, that foam filled chambers are better than just airtight because if the chamber is ever compromised, filled with foam it will never sink, but if it is just air filled it will certainly fill with water and sink.

    BobBill, I want to restore my kite to factory condition. I saw the old advert, which is a gem by the way, and would be interested in any other information you may have about the design. I've been looking for years online and have turned up very little beyond the wikipedia page. I'm especially looking for the specs on the original dagger-board, the one I have is definitely not the original. Also, anything concerning hull numbers and their place of manufacture would be great. Anything really, I would greatly appreciate. And if I can help with any other questions about the work you are doing on yours please let me know.
     
    Last edited: Dec 28, 2009
  9. PAR
    Joined: Nov 2003
    Posts: 18,018
    Likes: 353, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Kite sailor, this is an old thread, but hopefully he's still watching.

    The "industrial" foam you're going to use in very likely 2 part polyurethane, probably 2 pound density stuff. Unless you can control the environment perfectly (like have it done inside an air conditioned room with dust and humidity control, you'll just end up with new foam that will soak up moisture. It'll do it at a slower rate then the stuff you removed, but it will still soak it up.

    I'd strongly recommend you place drains aft, in the transom so that the chambers can drain any accumulated moisture while living bow high on the trailer. If the foam is there, it will prevent this and you'll slowly pick up moisture weight as the years go by.

    This isn't my first picnic, I've got a wee bit of experience at this sort of thing. Your picture essay is worth a thousand paragraphs. Thanks for the post Kite sailor.
     
  10. kite sailor
    Joined: Dec 2009
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Boston, MA

    kite sailor Junior Member

    Thanks for your thoughts PAR. I will pass your advice on to the gentleman who will be installing the foam. And you can be sure there will be a drainage in the transom. And yes the pictures are a wonderful documentation now if I could just find out some more information on the design... Thanks again hopefully BobBill will check back.
     
  11. PAR
    Joined: Nov 2003
    Posts: 18,018
    Likes: 353, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Bags would be a better choice, they don't absorb moisture and will let any accumulated wetness drain off. BobBill posted on this forum a few days ago, so I'm sure he'll be back.
     
  12. TollyWally
    Joined: Mar 2005
    Posts: 777
    Likes: 26, Points: 0, Legacy Rep: 423
    Location: Fox Island

    TollyWally Senior Member

    Kite,
    I just thought I'd commend you for your photos. A picture's worth a thousand words and you brought a lot of clarity to the table by assembling your photos before posting.

    PS Par's remarks about the foam are worth considering before you button her up.
     
  13. sagtadd
    Joined: Dec 2009
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Boston, MA

    sagtadd New Member

    Kite History

    Bob H.
    In the above post you mention "This boat was made after Brunswick took over and the firm was in trouble, so they did take shortcuts that Newport and Carter Pyle likely frowned upon." This statement seems to imply that you have some resource of information on the designer, manufacturer and perhaps history of the Kite. I am writing an article on the restoration of my Kite, but I have very little information on the background and history of this nice little boat. If you have any information of that kind, such as a manufacturer's borchure or other material, would you mind sharing it. I could go to a web site where it is posted and read it only. I will give complete credit to any resource, either published or personally communicated, such as in e-mail. I in no way want to usurp anyone's copyright on the information. I hope the article, if published, will engender more information on this boat, perhaps even bring out more owners and people who are restoring their boats. Thank you in advance....Sagtadd
     
  14. BobBill
    Joined: Oct 2009
    Posts: 693
    Likes: 10, Points: 18, Legacy Rep: 157
    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Kite Information

    Sagtadd, (and Sailor) I will forward some of the data from my other computer and will also give you the address of some gents in CA who are very much into restoring Kites and may have more information than I do.

    I am an old sailor who had one in the 60s and am going back to it...very sensible boat to putter in and to teach active kids to sail in, as well as safe and so on...

    You can PM for email address and I will send the pics and links I have direct, as well as the address of the fellows who are restoring the boats in
    CA.

    Sorry for the tardy response Sailor and Sagtad, but I have been shoveling snow ;] Will get back to you soon.

    Some pics; I have a bunch.


     

    Attached Files:


  15. sagtadd
    Joined: Dec 2009
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Boston, MA

    sagtadd New Member

    email me direct

    BobBill,
    Here is my direct e-mail so you can mail the information you spoke about. Thanks very much. the address is lmabbey@comcast.net.
    Best regards for New Year.....Sagtadd
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.