Tuesday, March 27, 2007

First Hull Aligned and Leveled

Today I installed all the bulkheads in the port hull after first working on the keel wires to straighten a twist in the keel strip. It took some effort to get all the bulkheads seated properly and lined up on their position marks, then I pulled the upper sides of the hullsides together with a Spanish windlass near each bulkhead position, as shown below. This simple method worked well, and holds the tension well since the line I used was some old Dacron Sta-Set that has low stretch.

The hullsides at the stern are under more tension than any other part of the hull when bent into place against the sternpost. Rather than fighting wires in this difficult area, I used screws through the sides and directly into the sternpost after first making sure it was vertical.

Final alignment was achieved through the use of various levels and taut lines, one from near the top of the stem and sternpost and one from the bunk bearers from bulkheads 1 to 5. The hull was nearly self-aligning, thanks to the accurate design of the parts by the Wharram team, but some minor tweaking was easily done after the V-supports were blocked up under the keel and the tension was released on the ropes I had suspended it from yesterday.

When I was satisfied that everything was level and straight, I did an intial epoxy pour with a slightly thickened mix that filled the narrow gaps between the keel strip and hullsides. This will hold things in place while I'm away for a few days working. It will likely be sometime this weekend before I can continue work on the hull, but it feels great to see it taking shape and at last it feels like this really is going to be a boat.

Monday, March 26, 2007

Port Hull Assembly

I had a productive day beginning early this morning with finishing the epoxy coating on the other hull panel. This was cured by noon and this afternoon I began assembly of the port hull, first by drilling the wire stitch holes in the stem and sternpost and then in the bottom edges of the hullsides. Putting in the wire stitches took some time, but went smoothly. Below is the finished wiring job, with the hull panels flat on the workbench.

Since I used screws to hold the top edges of the hullsides together at the stringers, as Thomas Nielsen suggested in his blog about building his Tiki 26, the whole affair was quite stable to move once the wire stitches were in place. I needed to get it off the bench, which is located on one side of my work shed, and move it out into the yard where I could then back it into the other half of the shed where I have the space to build it. (Moving it out into the yard to do this was necessary because of the center support posts that are in the way in the shed.) Moving the assembly was easy with the use of one of my hull dollies I built for my Tiki 21, Element.

After rolling the hull back into the shed on the other side of the posts, I then made two slings from some old jib sheets and hoisted the hull from the rafters, lifting it clear of the dolly and high enough off the ground so the skeg would not touch. I couldn't wait to see how the hull was going to look so I got some bulkheads and tried to open the hullsides. As it turned out, the wire stitches were a bit too tight, so I had to first loosen all of them before I could fit any bulkheads. With the stitches loose, I was able to spread the sides apart with no problem. This is much easier to do with the hull suspended in slings, rather than resting in cradles. (Another great idea from Thomas.) I still had some prep work to do on the bulkheads, such as sanding the cured epoxy near the edges where the bulkhead to hull panel fillets will be, and making some temporary stiffeners to screw onto the top edges above the sheer line. Since I'm making a slight modification in this area, my bulkheads are cut off a few inches above the sheer and I won't be adding permanent deck beams or the cabin parts of the bulkheads until the hulls are built to this level. Getting to this point is inspiring, and I decided to take another day off from my paying work so that I can finish the bulkhead installation tomorrow and try to get things aligned and leveled so that I can begin joining these parts together permanently with epoxy.

Assembling the Hullsides

Yesterday I assembled both hullsides for the port hull. This involved joining the three panels that make up each hullside with buttblocks, and glueing on the stringer that goes on the inside of the top edge of the lower hullsides. Since I only have room for one of these at a time on my workbench, I had to wait on the epoxy to cure before assembling the second one. Shown above is the first side, which I moved out in the yard onto some pallets for applying the second and final coat of epoxy to the whole inside surface. The other side is now assembled on the bench. The epoxy glueing the butt blocks and stringer on it was not cured last night, but at first light this morning I'm going out to remove the screws and clamps so I can get a coat of epoxy on it. Hopefully today if the epoxy cures fast enough I'll begin the wire stitching process and will get the two hullsides wired together along with the keel strip, stem and sternpost.

Saturday, March 24, 2007

Scarfing Keel and Hull Stringers

Today I moved my table saw and other tools from the garage shop to the newly-roofed building shed, along with the finished stem, skeg, and bulkheads for the first hull I plan to assemble, which will be the port hull. I only had a couple of hours to work today, but in this time I was able to rip some 18' by 3/4" Doug Fir stock into strips for the keel and the hull stringers that go on the top edge of the lower hullsides. Since these parts needed to be longer than 18', it was necessary to use scarf joints to extend them. Shown below are the four stringer parts that I used to make up the two long stringers, which are approximately 23' long. The fastest and easiest method I've found for cutting scarfs is to stack them with each one staggered back the amount of the scarf ratio, then cut the excess material down with a handheld power planer until a smooth "ramp" is created. This is further smoothed with a belt sander. Turn half of these around so the cut surfaces are end to end, and glue them together with epoxy.

Here are the staggered pieces, in the first stages of cutting down with a power planer. Since I wanted a 10:1 scarf ratio on these joints, the amount of offset is 7.5" (for a .75" plank thickness).

The finished ends after smoothing with a belt sander. (These are shown slightly out of alignment for clarity.) This is much easier and faster than it looks, and only takes minutes for the whole operation once you've done it couple of times.

The finished scarf joints clamped for glueing. Keel stinger on the left, two hull stringers on the right. These joints will be cured in the morning. I also sanded the epoxy coated inside surfaces of all the port hull panels, in preparation for a quick second coat. Then I will be ready to join the panels with the butt blocks and glue on these hull stringers.

Friday, March 16, 2007

Shed Roof Complete

The shed roof is now complete, and should be leak-free for much longer than the time needed to build the Tiki 26. For this mild climate, this is the ideal place to build: plenty of ventilation to avoid buildup of dust, a dirt floor so that epoxy spills are no big deal, and strong enough rafters to hoist the hulls up for turning and moving. While I don't have enough width inside to assemble the boat with the crossbeams, there is enough room to build both hulls at the same time, and it will be a simple matter to wheel them outside for assembly, painting, fitout and rigging.

Wednesday, March 14, 2007

Preparing the Boatbuilding Shed

Now that I have completed the fabrication of all the parts required to begin building the hulls, with the exception of finishing the second coating of epoxy on some of them, I have turned my attention to the next necessary step - putting a new roof on the shed that I will build them in.
I built this 16' x 28' shed several years ago, but in my haste to throw it together took some shortcuts that eventually resulted in a perpetually leaking roof. No amount of patching would do any good at this point, so back when I decided for sure to build a Tiki 26 earlier this year, I knew that I would be facing the task of tearing all this old tin roofing material off, replacing rotten framing and putting on a new roof with better materials and methods.

After several weeks of working hard for other people, I took the day off Monday and sailed Element, my Tiki 21 out to West Ship Island, one of the barrier islands off the coast of Mississippi. See my post about this trip here: http://tiki21element.blogspot.com/ This much needed break was quite refreshing and the perfect sailing conditions on board a great sailing design was just what I needed for motivation to attack that old shed with determination. I put in 9 hard hours today, getting all the old roof removed and the new framing on. Tomorrow all that remains to do is to add a few more framing members and then screw down the new sheets of tin roofing. Then, I'll clean out the work area and get it organized, and hopefully I will soon begin to assemble the hull panels for the first hull. I plan to post some photos of the shed project after it's all finished tomorrow.

Wednesday, March 07, 2007

Rudder Lashing Holes Complete

I've been so busy with my work lately that work on the boat project has been sporadic at best. The fairly involved steps I've taken to prepare the sternposts and rudders for lashing on later when the hulls are built are now all done. I finished by drilling the actual holes yesterday and today I started applying the second coat of epoxy on the sternposts, stems, and bulkheads. The following photos show the final steps in this process that I described in previous posts. Below are both rudders and sternposts with the areas of the lashing holes and hardwood inserts taped off for applying the fiberglass. Using good quality masking tape like this is a good technique to use when you need to apply fiberglass cloth to a specific area. Just after the epoxy cures enough so that the cloth won't pull away, but before it gets really hard, you can cut the glass cloth just inside the tape lines with a razor blade and the pull the tape away to leave a neat edge.

The photo below shows a close-up view of one of the insert areas, with the piece of solid mahogany rounded over and sheathed in fiberglass. Just below the insert you can see the epoxy filled slot where the lashing holes will be drilled.

After two coats of epoxy were applied to the insert areas, I sanded the glass enough so that it could be marked on, then made up a template to get a consistant spacing between the 5mm lashing holes - 7 holes on the sternpost side and 6 on the rudder side. The layout and spacing between the holes that is shown on the plans insures that the lashing lines won't chafe by coming into contact at the crossover points.

With all the holes accurately marked using the template, it took just a few minutes to drill them out on the benchtop drill press. Much easier than trying to drill a straight hole with a handheld drill on a vertical sternpost in an assembled hull!

This last photo shows the result, lashing holes that are correctly aligned and safely isolated from the surrounding wood. I wonder how many hours of work are ahead of me before the day when I can finally lash those two rudders in place....