Bateau.com PH18 CNC kit notes 1/5

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1 Bateau.com PH18 CNC kit notes 1/5 These building notes must be used in conjunction with the standard building notes included in the plans package for this boat. The PH18 kit is assembled as described in the plans building notes with a few minor differences. Some very small differences in dimensions exist between the plans and the kit parts. The kit is more accurate than the plans. The plans show dimensions with a tolerance of + or 1/8 but the kit plywood parts are cut directly from the 3D model with a precision close to 1/1000 of 1. Other differences are listed below: The hull panels are assembled with puzzle joints. The hull panels are pre drilled for the stitches along the chine and keel. All the stringers, bulkheads and frame notches are based on notches 1 deep in the stringers. The mahogany clamping board is replaced with a plywood clamping board made from 2 layers of plywood and extends all the way down to the keel. The stringer parts are assembled with butt blocks same as on the plans but we use wide butt blocks that fit exactly between the frames. The deck is cut too large, with a 1 offset along the sheer line. Small differences in the way the plywood bend require a small safety margin. We do not cut any holes or openings in the bulkheads and frames. The size and location of those holes vary with each builder and some builders prefer to install hatches in the deck. The sole parts are cut to use either butt blocks or fiberglass splice between the frames. CNC machine requirements and the use of metric sized plywood sheets (98-3/8 long) result in small changes in the nesting (layout of parts on the plywood sheets). Build the boat as explained in the standard plans building notes: upside down on a flat level floor or on a pair of strongbacks.

2 Bateau.com PH18 CNC kit notes 2/5 Recap: The lower face of the deck is the baseline but there is nothing to measure. Assemble the side and bottom panels with fiberglass splices. Epoxy glue transom and clamping board.

3 Bateau.com PH18 CNC kit notes 3/5 Note how the transom plywood layers are staggered. The outside face of the transom layer is lined up with the keel side of the stringer. All other layers are lined up flush with the bottom. This is optional but it eliminates a large gap to fill with putty. Assemble stringers with their butt blocks. The butt blocks fit exactly between notches and fit only one way. Note that the butt block always goes on the inside, towards the center line of the boat. When gluing the stringers together, remember that they are mirror images, not exact copies. If you don't put them on the inside, you will have to sand the edge down to avoid interference with the bottom panel. Set up frames and bulkheads ( we use them as molds), insert stringers. At this point, the builder may need to sand the inside of the notches. We cut them tight but a little play does not hurt to the jig set up. Note that at frame A, the notch for the stringers may look to deep. The bottom side of the stringer may be a little below the level of the frame. This deliberate, do not try to 'correct it.

4 Bateau.com PH18 CNC kit notes 4/5 In the picture, the gap is exaggerated for clarity. Add the bow mold. Add the transom assembly. The stringers will give the correct angle and when planking, the side panel will correct an eventual small difference in angle. Use temporary cleats to secure all the parts together. Check diagonals: the planking will not allow you build a twisted boat, they will not fit if the jig is not square but get the framing as square as possible, it is easier to move frames around at this stage. Cover all edges except transom with plastic sheet or tape: you do not want to epoxy glue the hull skin to the jig. Pay attention to the bow mold: it is a throw away part, it can not be glued to the hull. Assemble the hull panels: lightly coat the edges of the puzzle joint with epoxy, press them together and wait for the epoxy cure. Some builders like to cover the puzzle joint with fiberglass tape (biaxial 12 oz.) before planking, we recommend to do it with the panels on the jig. One layer each side. Plank the jig with the hull panels. As we say in the building notes, use as few stitches and screws as possible, let the panels take their natural shape. The kit panels are drilled with holes for stitches every 12. Close to the bow, you may want to drill a few extra holes. Check the sheer: it should not lift away from the sole or strongbacks. Proceed as described in the plans building notes. About the sole: we cut the sole in three pieces. The middle, between B and D, is made from two parts with a fiberglass splice. The two other pieces are the forward part between A and B and the rear one between D

5 Bateau.com PH18 CNC kit notes 5/5 and E. Many builders install only a partial sole between D and E, for example to leave room for a deep baitwell. Some builders lower the sole between A and B to install a higher gas tank. About the middle part: it can be installed in several different ways. This most common one is to cut frame C at the sole level, drop the sole in the hull between B and D and install the upper part of C on top of the sole. The bottom of the anchor well is optional and is not cut but there is sufficient plywood left over for it. The bow mold part is large enough if you want a sole in the anchor well.