STATION MOULD LOFTING INSTRUCTIONS
For the station molds, tape some heavy construction paper to a piece of MDF. Make sure one corner of the paper aligns exactly with the edges on one corner of the MDF. Using a carpenter's framing square, not a tape measure, draw a vertical centerline on one side of the paper, being sure to allow enough horizontal space for half the station mold. Mark off the horizontal distances (half breadths’) from the centerline on the bottom edge of the sheet. Traditional tables of offsets use 1/16” to denote fractions so 2.8 or 2 8/16 means 2 1/2”.
Mark the 0 or waterline on the centerline high enough so you can add the below waterline points. Make this an even inch or mm as you will be measuring up and down from this point. Place one arm of the square against the bottom edge of the MDF, the vertical arm should be parallel with the centerline. Place the vertical edge of the square on the horizontal reference point (half breadth) for the waterline. Using the graduations on the square, measure up to the vertical reference point for the waterline. If you measured up 6” for the waterline mark on the centerline then 6” is the waterline mark on the ½ breadth. Mark this point with a pencil. Continue adding vertical and horizontal reference points until you have a series of dots that look like half a station mold.
Drive a 1 ½” finishing nail about ½” into each point, and make sure the nail is straight. Make a batten of straight-grain wood thin enough to bend around the points. Untapered sail batten works well too, whatever you use needs to bend with an even curve, with no kinks. Place the edge of the batten on paper and bend around the outside of the nails. You can use a spring clamp to hold the batten to the top nail. The batten should touch every nail evenly, with no gaps or kinks. If you have nails out of place recheck the measurements. Mistakes in the tables are not unheard of so if everything checks out and you still have one out of line blame the designer. Do not force the batten into an unnatural curve unless it is required by the design.
Mark a line on the inside of the batten between nails, pull the nails, and cut the paper ½ station on the line with a razor knife or scissors. Tack or tape the ½ station onto the MDF and mark around the edge, mark the water line points on the MDF at the edge of the paper. flip the pattern over, match up the waterline marks and draw the other half. Lay a straightedge across both waterlines before lifting the pattern to make sure both halves are aligned. The same principle can be scaled up to any size boat although it is usually easier to draw both sides directly on the bulkhead or mold frame for larger hulls.
Or you can save the hassle and get Noah’s to do it on our CNC machine.