Tuesday, January 18, 2011

I Should've Known!

Updates are added in blue text and the photos are new.

Boat building is bound to have it's aggravations.  I've found three.  I'm only revealing these issues for completeness, each of them is not that big of deal in the big scheme.

Starting with the smallest; a small area (2" by 4") of plywood on the starboard side around frame 169 began to delaminate it's outside ply.  What disappointment when you spend the extra money on high quality materials.  I think this was all caused due to a small flaw in the outside layer of wood, mixed with the high induced stresses from bending, and mixed with the cyclic temperatures and humidity in the garage.  This area has already been repaired by glue and proper clamping.  I've inspected the entire rest of the hull and haven't found any other areas of concern. Update; the image below is the repaired area.

For the second issue; when I cut out all of the frames I followed the templates.  Well the templates for the outboard edges of each frame were straight. Upon inserting the frames into the boat a gap appeared between each outboard edge and the hull's side panel. The fix for this is to template the side panel's curvature into the frame, glue a strip of plywood (approximately 3/4" wide) onto each side of the frame, and cut the frame to match the templated curve. On the the first frame I've installed, frame 18, this worked perfectly on the first try.  Update; I happen to replace frame 53.5 and the image below shows the issue best.  For the other five frames I added a sliver piece between the frame and hull side panel.

Lastly, when building the strong-back, the cradle glued to the floor, I paid great attention to determining the height of each frame relative to the baseline string. Well mistakes were made, several of the cradles supports have gaps between them and the hull bottom. So, I'll take a step backwards, lift and support the boat off of the cradle, 3'ft high, adjusting the cradle's support position, and lowering the boat back into the cradle.  This will take awhile.  For the record the proper dimensions for each frame are as follows: Stem - 6.4", frame 18 - 4.75", frame 53.5 - 1.95", frame 89 - 0.7", frame 110 - 0.84", frame 124 - 1.22" frame 169.5 - 4.15", transom - 7.93".  These dimensions were obtained from the design owner who pulled them from the auto-cad files of the boat.  Now for the truth, I'm now convince I don't even need this cradle. So far each of the hull's plywood panels and frames have lined-up within the wide of the 0.5mm pencil line reference marks taken from the templates.  The boat is coming together extremely straight and the cradle is not necessary. I'm going to correct the cradle so the hull bottom can support my weight while gluing the interior. If I build another i550 I'm not going to bother with a cradle, instead I'll support the hull with foam mattresses and straps.   Update; The boat was light enough to lift and set on sawhorses.  This allowed me plenty of room to rebuild the seven hull supports located under each frame.  They are now evenly contacting the hull bottom.

Monday, January 3, 2011

The Fun Is About To Begin

Though the hull panels are assembled the boat is not in its final shape yet.  The center of the hull bottom still has a much flatter profile than its designed shape. The next task is to pull the hull side panels together to the designed dimensions. This will relieve some of the pressure on the bow allowing me to install the first frame and assemble the stem. Once the bow is complete temporary weights will be added to force the bottom panels down against the cradle. The the rest of the frames will be added, stay tuned! We'll see how that works out. Aligning the frames and gluing them in place will be tedious. How to contact us "apriltied at gmail dauht com".

The Hull Takes Shape

 The family; Connie, Josie, and Meredith really enjoyed assembling the hull with me on 1-1-11. Connie supported the panels, Josie fed the wire-tie up through the holes, and Meredith stuck them back to Josie.

No Christmas Party this Year-The House is Full of Boat Parts

Joining of the hull panels. I used glass cloth and epoxy to secure the plywood at butt joints. Two joints were necessary in each side panel and the hull bottom. Had I to do it again, I'd use scrap 1/4" plywood to overlay each of the panels to be joined.  It was very difficult to get the entire length of the butt joint to line-up in the same plane. If one were to use the plywood overlay you can press the panels into a straight joint.

The Foundation

Though it is not entirely necessary to build a foundation for a stitch and glue boat, I spent the time to construct a strong-back to better assure I end up with a straight boat and that the hull bottom comes out in the designed shape. The strong-back should remain straight as it is glued to the garage floor. I utilized a homemade water level, laser, and tight string to lay it out.

Template and Cut

I purchased a license to build i550 hull number 296, plans, and Tyvek templates from Watershed Sailboats for $240.00. I decided to use the templates instead of purchasing the kit for two reasons. I can't stand the thought of spending money on shipping to receive the twenty sheet plywood kit, and I want to make minor changes to the cockpit.  As designed the cockpit has sharp edges. I feel the sharp corners are stress risers and uncomfortable to sit on. I choose to build the hull of okoume plywood. Twenty, 1/4"thick, 5-ply sheets are required. Above, I'm laying out the templates on the plywood and tracing the edges. The living room is a comfortable place to work! Once the plywood is marked I cut the panels out using a jig saw, then final shaped them with them with a hand plane and sanding block.

The Keel is Taking Shape

The keel is beginning to take shape.  It is nine segments of African Mahogany laminated together. I'm hand planning it down and will achieve a NACA 0012 profile. I feel like I've walked 6 miles, 6 feet at a time. The keel receives two layers of glass cloth and a maximum thickness of 2" is allowed, so I have a ways to go. The keel's final shape will be needed in the later portion of hull construction to template the keel box from.

Beginning of a New i550 the 'Mist' Hull #296

Construction of a new i550, an 18 foot sport sailboat has began.  Upon completion it is intended that the boat will be sailed in the lower Chesapeake Bay. Hopefully this boat will catch-on, others will build one, and I can race it too! The picture above is the remnant from the keel showing construction start date.