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Is this an accurate way to mark the waterline? (Moved by moderator)

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I used this thin string and put it on a specific point at each end where I had marked the LWL on the bow and stern. At each end they are exactly 2 inches high. In the middle however, it is less than 2 inches. I pulled the string as tight as I possibly could without snapping the line, to try and make it completely straight all the way across, but it still looks off and the port and starboard sides look just a little different. So I'm wondering if string is not that accurate for this? Do I have to build a pencil marking jig? Is that my only option?


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Using a pencil jig is about the most accurate way to do it. Make sure your hull is level and you work on a flat, smooth surface. A string, no matter how tight you pull it, will always find the most direct route form point A to point B, unfortunately over a curved surface, it's not necessarily a straight line.



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Posts on this site have shown hulls mounted securely on a flat smooth surface and a wandering marker mounted on a block type of device that is ran around the hull by hand, marking as it goes a line that is a uniform vertical distance from the flat surface the hull is mounted on to the line being marked on the hull. 


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I level the surface the model sits on, in this case the build table.  This is the base.


The waterline is marked at the bow and the stern.  I measured up the sternpost from the heel for the aft mark, and propping the hull so that it was the right height from the base at a certain station, measured up the stem from the base for the forward mark.  In the picture you see a stick under the keel holding the bow up.  I measured from the heel aft, going forward on the plan to where the keel was the height of my stick above the baseline, 3/4" in this case, and simply placed the stick so it's aft side was at this mark on the keel.

The hull is then securely propped so that both marks are the same height from the base.


The hull is also leveled side-to-side using a bubble level - that's why the base has to be leveled first.  If your construction was accurate and symmetrical, you should be able to measure from the base to some point up the hull and get the same measurement on either side.


You need a block the height of the water line minus half the width of the pencil.  I cut the block to the waterline, put the pencil on it, and measured the distance between the two marks, and cut half that off the block.  Check it and cut it till it's perfect.  If you cut too much, shim it back up with card stock.  Check the pencil at both fore and aft marks.


The block has to be large enough to be stable while you move it and for the pencil to rest on it securely.  The pencil needs to be long enough to reach up under the bilges at the quarters without the block bumping the hull.


The waterline doesn't have to be struck in one movement.  So long as the hull is secure from movement, the block rests flat on the base,and the pencil lays flat on the block (remember it's usual octagon shape here), it should be perfect no matter where you start.  Note in the pics I actually struck it more than once 'cause I wanted it dark enough to see through the fiberglass that would cover it.


It's sounds complicated, but then a detailed explanation of tying a shoe lace would sound complicated too.


post-961-0-99803300-1380982980_thumb.jpg  post-961-0-39850400-1380982981_thumb.jpg

Edited by JerryTodd
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Certainly not expensive, and the base (board) the ship is setting on was also used for the planking. I actually found it easier to do the planking with the ship in this position.

There are dowels placed into the base jig that fit into the mast holes in the deck to hold the ship in place. I also used wedges of scrap wood glued to the base jig to level the ship all around.  Without any difficulty I could take the ship off of the base jig and put it back on as needed.


It worked very well but I have to admit that standing on my head for extended periods was a bit tedious..

Edited by bogeygolpher
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  • 1 month later...

Spencer, dark side is dark side.


Lot of problems you do not have following kit instructions. But, even in a kit building, if you must/want to step away of instructions ( adding details, implement some things and tehnics there are not in instructions) it is very easy to slip to the dark side  ;)


Modified quote from Star Wars


Fear ( could you can do it)  is the path to the Dark Side. Fear leads to anger ( if you couldnt) ; anger leads to hate ( hate your model) ; hate leads to suffering ( why I can not do this) ... Train yourself to let go of everything you fear to lose ( and to start over and over) ... You cannot escape your destiny ... I can feel your anger... it gives you focus, it makes you stronger!

Edited by Nenad M
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