I will now consider the work on the hull. Like many hulls, the Orco Millennium does not come with hull markings to show where to put the slot for the keel trunk and for the rudder post hole. It is up to the builder to locate these two places. Finding the locations is the first important step when working on your hull. If not done right, there are no second chances.
The goal when putting in the keel trunk slot is to get it exactly on the hull's centerline. If the keel is not on the centerline, it will not be aligned with the hull, and it will effect the boat's sailing. This also goes for the rudder post hole. If it is not on the centerline, the handling of the boat will not be true and counter steering will be needed to keep the boat on course.
To illustrate what I am describing, look at example 1. In the example you will see the boat hull's centerline in blue. This centerline splits the hull exactly down the center, and is where the keel trunk slot and rudder post hole need to be positioned. How does the builder find and mark the correct spots without errors? It is not as hard as you think. This article will describe the technique that I have used with success. The important thing to remember before you start is to get the correct measurements as to where the keel trunk slot and rudder post hole will be located.
For my hull, the distance from the bow to the leading edge of the keel needed to be 18 ½ inches. Again, it needed to be 18 ½ inches from the bow to the leading edge of the keel (not to the slot). Marking the position on the hull is made simple with the use of some tape and string.
Before getting out the ruler and measuring, the first task is to approximately locate where the centerline should be. Get some thin, white sewing thread and some brown paper tape. Flip the hull over, and tape the sewing thread on the tip of the bow (see photo 1). It is very important that the sewing thread is at the exact center of the bow. If it is not at the center, the rest of the centerline will be off. Make sure the thread is secure to allow it to be strung the full length of the hull. To find the exact center at the stern, where the hull meets the transom, simply measure up both sides where the stern and transom meet (see photo 2). Take special care to measure correctly. Once you find the exact center, mark it. At this point, don't tape the thread to the stern yet.
Next, butt the hull's bow up to a wall at a ninety-degree angle to the wall. Take the yardstick and find the 18 ½ inch point on the hull. Remove the thread and place a strip of brown paper tape at the 18 ½ inch point, see photo 4. Next, replace the thread back at the center point of the stern, and find the rudder shaft's 32 ¾ inch point. Remove the thread, and again place a long strip of tape before and after of the 32 ¾ inch point, see photo 6. The idea here is to place tape in the area where the keel trunk slot and rudder post hole will be so there will be something to mark on.
Now replace the sewing thread at the stern's center point, and pull it taut. If the thread is not quite at the center on the bow, put it there. If the thread is over to the one side too much, put in the center. The idea is to get the thread as close to the centerline of the hull as it can be by eye balling it. You now have a centerline that is almost right, now comes the job to make it exact. The goal here is get the thread in the general area of the exact center of the hull so the correct measuring can be done to get the thread in the exact center.
To place the sewing thread in the exact center of the hull, once again place the boat's bow so it is a ninety-degree angle to the wall. Now take the yardstick, and accurately measure 18 ½ inches then mark the spot on the tape where the thread is. While you at it do the same for the rudder post hole. Measure 32 ¾ inches and mark the spot on the tape where the thread is. Your measurements must be accurate, so double check your work. Mistakes at this point are not what you want.
To find the exact point where the centerline is will require some measuring and thread placement adjustment. What I have found to be the best for measuring is a cloth measuring tape. It forms to the outside hull shape and will not scratch the hull. To locate the exact center line it will be done by measuring from the gunwale to the thread center line on both sides, see photo 3. Make sure the thread won't move while you are measuring, and come loose from the position. To do this you need something to keep the thread in place. You can use tape, but when you lift up the tape to move, the thread will move with the tape, there must be a better way.
There is a better way, it is called Silly Putty, that is right Silly Putty. It "sticks" to the hull well, but it is very easy to pull off. It leaves no residue, costs less than a couple dollars, and it is easy to buy. The best thing about it is if you need only to move the thread over just a fraction of an inch, all you need to do is to push the Silly Putty over, and the thread moves with it. This way you can measure and place the center thread accurately without fear of the center thread coming loose.
To start the process, hold down the cloth measuring tape at the zero point at the gunwale, and then pull the measuring tape over the hull to the center line thread at the 18 ½ inch point. Carefully mark the spot where the center line thread is, and take note of the measurement. Next, go to the opposite side of the 18 ½ inch point, and do the same.
Note the difference in the two measurements and move the center line thread half way between the where the center line thread is and the new measurement. Keep doing this until both of the two measurements come to the same point on the hull's center line thread. When done mark the spot, you now have the spot where the leading edge of the keel fin will be. Again, double check you work, it is best to be safe now than sorry later.
Now that the spot where the leading edge of the keel fin has been located, now comes the fin's trailing edge's spot. Lay the keel fin on the hull where the fin's leading edge is at the 18 ½ inch spot. Then mark the spot on the center line thread where the trailing edge is (you can measure the length between the leading and trailing edges of the fin and mark it on the hull at the center line thread if you like). Start the measuring of the trailing edge of the fin like you did for the leading edge. Once done, double checked, and tacked the thread down with Silly Putty. You now have the exact center line at this point of the hull. Now comes the easy part. Again lay the fin down on the hull with the leading at the correct 18 ½ inch mark, and mark on the center line where the keel trunk slot is at. The exact position of the keel trunk slot has been located, see photo 5.
Now comes the location of the rudder trunk post hole. With Silly Putty still holding the sewing thread at the center line where the keel trunk slot is, this job won't be hard. Just like finding the center line for the keel trunk slot, use the cloth measuring tape to locate the center line. Measure from the gunwale to the sewing thread on one side, mark the spot and take not of the measurement. Then switch to the other side and do the same, adjust the thread until it measures equal from both sides. Once done you now have the exact center line spot for the rudder post hole. Again, double check your work, not making sure everything is right now means mistakes later on.
In closing before any project is started be sure to think it out and plan. A project without planning will cause grief for the builder. What I have described in this article may not be the best, but it does the job. The idea is to gain information, and maybe discover a better way to do it. Just be sure to double check your work, it makes the job easier. Finding where to place the keel trunk is not quite done. There is one more step to do to make sure the keel goes in the right spot under the hull. To do this it will require placing the keel bulb into the hull while the hull sits in water. The next article will explain how and why of doing a water tub test, see you then.