Complete rebuild starts in earnest, advice needed...

Discussion in 'Boat Design' started by Salmoneyes, Jan 26, 2019.

  1. Salmoneyes
    Joined: Sep 2018
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    Location: Southern Oregon

    Salmoneyes Junior Member

    Finances will finally allow this project to grab 2nd gear... My first order of business is to get the hull level, then start measuring it since it strayed so far from the plans.

    My current concern is which comes first, the chicken or the egg?

    Part of me thinks I should get the measurements from the hull first..(not sure what thats called in navel architecture, but Im calling it my take off).
    I would like to get advice on the best way to go about getting all those measurements from a built hull so I can have a starting point for all the mods. IMG_2880.JPG
     
  2. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    Your "order of operation" depends what you are trying to correct.
    When you say "get the hull level," do you mean something like the deck is warped or something ?

    If you can list the problems and or desired changes, it will be a lot clearer to others.
    "Level" is very relative.

    A few weeks ago I say a video about a guy trying to replace a compression post, and using a spirit level to make it "vertical".
    That was possibly an unnecessary way to do it, as the whole aim of a compression post is to align it with the direction of the mast, which may be raked slightly. The actual verticality is so relative, especially as his boat was floating in water.
     
  3. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    Bearing in mind there are naval architects and highly experienced DIY crew here, i wouldn't necessarily take on board this advice..
    You need to work out what you've got first, I would start with some graph paper as large as you can get,[a2 but in imperial?] then determine a line dead centre ..a string line ,..[?good luck, maybe run a string line along the keel and up] bow to stern mark off even spaces up the centre of the boat, in feet I suppose, for you. It may help to get[make] a big T square so you can draw across the boat at each station, every yard or foot preferably maybe use a plumb bob [no wind] where the cabin is in the way. Then transfer your information onto the graph paper. Side profile is trickier I can only think of using/ making a rigid frame that wont buckle that can be swapped to the other side when the first is finished . The more complicated areas will need more detail/measurements. You'll have to wait for someone that knows the formulas to work out the rest if required Disclaimer , I'm a backyarder that' s just browsing the forums, having a cuppa,.. taking a break from making stuff,. it will be interesting to read how the experienced folk would approach the problem...,hope this helps , regards
     
    Last edited: Jan 27, 2019
  4. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    "You need to work out what you've got first"
    Yeah - wot I said.
    So would you recommend a complete analysis of its lines if he was just adding a cabin roof ?
     
  5. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    You beat me to the send button Watto, If it is a total restoration it would be interesting to find out whether there are twists or buckles, then try and decide if it was the original build, damage or a repair that heated and stretched /warped it don't you think? Most likely a beaching for a twist or an embarrassing meeting with a pier if a forward gunnel sits high or low..or all those things .,nice to know what you've got. But using it for awhile you would eventually pick it and being steel and no racer it probably doesn't matter, setting up the mast would be a telltale?
     
  6. Heimfried
    Joined: Apr 2015
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    Location: Berlin, Germany

    Heimfried Senior Member

    This could be helpful:
    Other Publications - Boats: A Manual for their Documentation DIGITAL https://www.woodenboatstore.com/product/Boats_A_Manual_for_their_Documentation_DIGITAL/special_publications

    Free download of a pdf, which is originally dedicated to antique (wooden) boats. But it deals with measuring an existing boat hull.
     
  7. Salmoneyes
    Joined: Sep 2018
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    Location: Southern Oregon

    Salmoneyes Junior Member

    My bad,,...
    Level----The boat apparently was built with the pilothouse floor parallel to the bottom of the keel, and supposedly to the waterline. I want to get the bottom of keel level, and see if thats correct. Im assuming I will be able to establish how she sat in the water, ie heavy front to back or side to side. .

    The term I recall from Ad Hoc was its "stability book". Ive looked at the study plans and spoke to the designer, and the boat does not match plans in several areas, therefore I need to know what I have before I start changing it...

    The mods are predominantly going to center around getting her weight down. She has a LWL/disp ratio of 423. We removed over 2000 pounds of teak, which will not be going back in, and we removed 500 pounds of steel water tanks which will not go back in.
    We considered downsizing the engine for a lighter unit, but decided what we have was better.

    The hull is stripped inside and the welds are beautiful (it was built by a ship builder in Sweden) the plate is straight and the last blasting showed no fairing. They used 6mm steel instead of the 4mm as designed is the reason for her weight. They also extended the keel. The builder said the boat sat 8 inches deep in the water than expected. There was also some issues that were resolved by changing the steel marble ballast to lead and by adding an additional 500 pounds. In an effort to lighten her, I think Im down to finding any issues that could have caused it to require more ballast and resolve that.
    He swears she sailed beautifully from Sweden and they hit 10 knots running with a twizzle rig.
     
    Last edited: Jan 27, 2019
  8. Salmoneyes
    Joined: Sep 2018
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    Location: Southern Oregon

    Salmoneyes Junior Member

    This is roughly what I had in mind. Once level, I thought about starting at the current waterline, and layout 1 foot marks starting at her mid point, and then continue working out until I had the whole hull laid out with 1 foot squares.. If I built a floor, I could plumb bob down from each intersecting line to transfer the hull into a single dimension drawing on the floor... That is all simple stuff, but is that really necessary? I was wondering if there was a better way.?
     
  9. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    She’s meant to be heavy and slow! IMO it’s a waste of time and money to try and get every gram of the ballast in the perfect spot, and removing too much weight is likely less safe than having a bit too much, and you’ve already lightened considerably.
    If it indeed ever saw 10knots, it was downwind in a big following sea!
    There is a better way: Get the mechanicals squared away, paint her up nice, and get out on the water, and enjoy her for what she is.
    If it made it to Oregon from Switzerland in its current trim, I would be inclined not to worry.
     
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  10. Salmoneyes
    Joined: Sep 2018
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    Location: Southern Oregon

    Salmoneyes Junior Member

    Agreed on all points. However an LWL/D of 423 is a bit excessive isn't it?

    I would still like to generate a stability book on her if for no other reason than piece of mind....
     

  11. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    You can adjust the ballast when it's in the water, check the hull under the shower, cheers
     
    rwatson likes this.
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