Tuesday, April 29, 2008

From Square to Round

(Posted by Scott B. Williams)

Today was my last day in the shop on this trip to Florida, and I completed what I came here to do, which was to build the Tiki 30 mast. This was also the most enjoyable work day of the trip, as I love the process of shaping a beautiful wooden spar from a rough glued up square box of wood. The chips were flying as I spent most of the day with a hand-held power planer, taking the square section first to 8 sides, then 16, and finally 32. The final rounding was done with a belt sander.

The first photo below shows the square section as it appeared when the clamps were removed first thing this morning. The plans show the amount of offset to mark the lines for the first cuts that take out the corners and produce an 8-sided section. I measured and marked these lines and cut the corners away roughly with a worm-drive Skilsaw first.

The final cutting down to the 8-sides lines was done with David's 6-inch Makita power planer.

Once the spar is cut to the octagonal section, two straight lines must be marked exactly 14mm from each remaining corner. This process took a bit of time. The corners were then removed with a smaller 3-inch Makita planer. Once this was done, there were 16 even sized sides. I removed the remaining corners from all these sides with the small planer, which resulted in 32 sides.

From this point, I was able to shape the mast to a round section using a 3 x 18" belt sander with a very aggressive 36-grit belt. This entire process took a full day, working alone, but now the mast is done except for finish sanding and fitting the top plate. It came out straight and is undoubtedly very substantial. While it is heavier than my Tiki 26 mast, it is not as heavy as I expected, consider the 25mm wall thickness.

The filleting and shaping of the tabernacle was also completed today and it is now ready for fiberglass sheathing.

Here is an aft view of the tabernacle structure, showing the hardwood mast step.

Monday, April 28, 2008

Mast is Assembled, and Tabernacle Built

(Posted by Scott B. Williams)

I've been working in the Boatsmith shop for 8 days now and we've accomplished a lot on the Tiki 30 project, with many parts in process simultaneously while I've been working on the mast. The full crew has been back since Friday, and David and I worked alone on Sunday while they took the day off.

Today I completed the assembly of the mast, and hopefully tomorrow will begin the shaping process - taking it from the rough laminated box section to a perfectly round spar. I've also complete the building of the mast step and tabernacle assembly that fits onto the mast beam. The photos below show the steps taken to get to this point.

As I did on my Tiki 26 mast, we installed conduits for masthead wiring and a VHF antennae coax. We used thin-wall PVC pipe for this, as it can be easily glued with epoxy if it is sanded first. One conduit was installed in each mast side, exiting near the foot at an angle and straight out the top. The photo below shows one of the exit points, through a hole drilled at a low angle. The mast foot is also visible glued to the other side half to the right.

Here the aft wall is being glued to one of the side walls. A level and straight form like this helps tremendously, enabling this process to be done in control without a mad rush to assemble all the parts as once as shown in the plans.

Today we glued in the final piece, completing the square box section of the hollow mast. It is almost completely hidden under the dozens of clamps used in the assembly. Having all these clamps is another great aid to building a mast, and there is certainly no shortage of clamps in the Boatsmith shop.

Here is a view of the clamped assembly from the other end. In the background you can see some of the other processes going on in the shop. Both hulls are inverted for shaping and fiberglass sheathing, and the crossbeams, tillers, rudders and gaff are all in various states of completion.

Yesterday I began building the mast tabernacle. This is quite a stout structure that is not shown on the Tiki 26 plans, but I like it so much I might incorporate it on the mast beam of Element II. It certainly will make raising and lowering the mast easier, and will provide more security at the foot.

Here is the complete tabernacle still in clamps, as it was glued up at the end of the day yesterday. Today I have completed the shaping and fillets, and tomorrow it will be sheathed in fiberglass.

Wednesday, April 23, 2008

Building the Mast

(Posted by Scott B. Williams)

I'm back in Jupiter, Florida this week, hired by David to build the mast for his Tiki 30 project. Working in the Boatsmith shop is always an interesting experience, and even more so on this project, which I've been involved in from the beginning in setting up this blog. A lot of progress has been made since I spent four days here helping assemble the hulls back in February.

Since I've already built the mast for my Tiki 26, Element II, I'm familiar with the process and so far the construction of the new mast is going smoothly. David and most of the crew have been out of the shop this week, working on a teak deck for one sportfishing yacht and the interior for another as described in his Liberty 42 blog. Most of the work I've done so far has been with one helper, Francisco, and it has been considerably easier than building a mast alone as I did for my boat.

David buys most of his lumber as rough stock. Below are the Doug Fir planks we started with. These are 18 feet long by 6 inches wide and a full 8 quarters thick. The mast walls for the Tiki 30 are 25mm (1-inch) thick, so we had to first surface this material with the planer and then resaw it to the proper thickness.

This is easy when you have the kind of serious tools David's shop is equipped with. The table saw shown here made resawing easy and also made it easy to saw the triangular wooden fillets required in the mast interior.

After processing the wood, the next step was to set up a form for laminating the mast parts to insure that we would end up with a straight spar. I used a similar system for building my Tiki 26 mast. The key is to insure that the form is perfectly straight and dead level. This insures that the finished spar will be true after all the individual parts are laminated.

David already had plenty of the large bending knees shown below that make up the form. The Boatsmith crew uses these for laminating teak covering boards for yachts and for such projects as the massive teak pergola we built last summer for a Palm Beach mansion. I set up the form to accommodate a length of 32 feet, as we are extending the mast by a couple of feet to provide more clearance for a bimini. Shade is essential for a boat that will be sailed in the tropics, and many other Tiki 30 builders have raised the mast height for the same reason.

On the backside of the table with the mast form, we have enough space to cut and glue the scarf joints. Here the side walls are being stacked four high to cut the scarfs. All the scarf joints are cut to a 12:1 ratio, so they are 12" long for the mast walls and 18" long for the square stock the triangular fillets are cut out of.

Cutting scarf joints is really easy with David's 6-inch Makita power planer. Here I'm using the stacking method with the planks each set back 12 inches, cutting them down to a smooth ramp using the planer.

By the end of the day yesterday, we had the two side walls completed, clamped on the forms with the triangular fillets glued in place.

The next step on the two mast halves shown above is installing the masthead crane and the pivoting mast foot. Below is the crane, laminated from solid teak, one layer in the middle 16mm thick and two outside layers 12mm thick oriented with opposing grain.

The mast foot and the matching step for the mast beam were also laminated today. These too are teak.

During periods of epoxy drying time when nothing else can be done on the mast, I'm also working on various other parts for the Tiki 30 while I'm in the shop this week. Today we laminated the rudders to the finished thickness of 40mm from two pieces of 9mm ply and two pieces of 6mm ply each. The laminations cured by late afternoon, and as shown below, I clamped them to a work table with the leading edges facing up so I can fit the hardwood inserts at the lashing points, as I described in my blog about building my Tiki 26, Element.

Monday, April 14, 2008

Rudders and Gaff

Work on Tiki 30 parts is still going on while the hulls are stored outside our shop until we can move them back in later this week. Some of the details that have to be completed include making small parts like the rudders and the gaff. Parts for the rudders were cut out yesterday and are shown on the table here. They are built up of several laminated layers of plywood to the required thickness, and then shaped and sheathed with fiberglass before installation.

The gaff parts were also laminated yesterday. The gaff, like the mast, which will be built next week, it is made of Doug fir for strength and light weight.

Here is the glued-up gaff, ready now for shaping and fitting of the gaff slider.

Friday, April 4, 2008

Moving Outside

The forward and aft crossbeams shown here are mostly finished except for fairing, priming and painting.

This view of stern deck of the port hull shows the coaming we built for the ice box access hatch.

We are now beginning work on fairing the hull exteriors in preparation for fiberglass sheathing. The first step is to make all the fillets at the stem posts, stern posts, and topside panel overlaps to smooth the transitions where all these parts meet. This view shows the transition from the sheer stringer to the topside panel.

Below you can see how the stern post is faired into the hull panels and the joint where the topside panel overlaps the lower hullside. Excess thickened epoxy is used to fill these transitions, and when it cures it will be sanded fair.

Here is a view of one of the bows, showing the filled in stem post and the various temporary screw holes that have now been filled.

After this filling was done, we loaded the hulls onto carts so we could move them out of the shop temporarily. We had to get them out of the way so that we can move the interior for the Liberty 42, which has to be taken to the Liberty Yachts facility for fitting into the hull.

Below you can see we have moved the hulls out of the shop and covered them with a tarp. They will have to stay outside for about a week while we fit the Liberty 42 interior on site and then bring it back into the shop for finishing. Once the interior is back in its place in the rear of our shop, the Tiki 30 hulls can be moved back inside for finishing. In the meantime work will continue on various parts for the Tiki 30: including the crossbeams, cockpit, gaff, mast, rudders and tillers.