Thursday, May 29, 2008

Companionways and More Cockpit Progress

We've been working on the companion way hatches this week as well. Here is the beginnings of one of them, consisting of a strong teak frame that will get a subdeck of plywood and then a teak overlay. These main hatches will be finished bright.

Here you can see the teak overlay planking being held in place with lead bags while the epoxy cures.

The companionway coamings and trim are also of teak.

Here is one of the beam lashing blocks, bolted glued and filleted in place. All 12 of these are now completed.

In this photo the cockpit ledgers that the cockpit hangs from on the beams are being clamped and glued in place.

Here the cockpit is hanging in place from the beams for the first time. Now this is starting to feel like a boat, and to feel much bigger. That's the way these Wharram catamarans are once they are assembled. The whole is definitely greater than the sum of its parts, and despite the fact that each hull is relatively small, when joined together by beams and cockpit structures, even a Tiki 30 has a big boat feel.

Another view of the boat with beams and cockpit in place.

This is the leading edge of the cockpit box, angled off to present less resistance to wave tops in a choppy sea.

One of the forward hatch openings can be seen here. These will be fitted with Bomar extruded aluminum hatches.

This is the view from inside the starboard cabin, looking aft at the electric panel. In addition to things like the battery switch and a circuit panel for navigation lights and other electrics, the navigation station will also be in this aft area of the starboard hull.

Building the Cockpit

The first step in building the cockpit is laminating the cored floor, which is a foam sandwich construction using a top and bottom face of 4mm plywood and a Divincell central core.

This is a big assembly and requires plenty of pressure to squeeze out all the air bubbles that might become trapped and insure a good bond between the panels. As you can see here, we threw everything we had at it to weight it down while gluing up the panels.

The finished sandwiched floor assembly came out just right.

Here is a view of the beginning of the cockpit assembly, looking forward from aft of the cockpit. The large side lockers are under the longitudinal seats. We also wanted lockers across the rear and the forward sides of the cockpit. All of these will provide needed storage for things like fuel tanks, propane bottles, the house batteries, a grill, snorkeling gear, boat hooks, dinghy oars, etc.

The forward locker that goes athwartships across the cockpit has a long storage space available for things like the dinghy oars, boat hooks, and spear guns. The lid to this locker will consist of a double panel hinged together that can be folded aft to form a double berth in the cockpit.

Aside from the cockpit, we also completed the T-shaped beam locating blocks that go on the bottom sides of all the crossbeams to lock into the beam landing blocks on the decks.

Saturday, May 24, 2008

Beam Locating Blocks

With the two hulls aligned and the beams resting in the correct positions on their locating blocks, our Tiki 30 project is now beginning to look like a catamaran. Getting precise hull alignment was quite a task, involving leveling each hull individually as well as making sure the stems and sterns of the two separate hulls were level with each other and in line fore and aft. Once this was done, the beams could then be fitted to the blocking on the decks.

The photo below shows forward beam with a clamped on lever weighted with a lead bag to hold the front edge down flat on the beam blocks. This lever is a bit hard to see with the background behind it, but was necessary to keep the beam flat.

The blocks on deck as well as the T-shaped blocks that fit on the bottoms of the beams to lock into these deck blocks are all made of teak, for durability. We are using the lashing method for the beams, Tiki 26 style, rather than the Tiki 30 webbing straps shown in the plans. We feel this lashing method is much stronger and more reliable, as well as simpler to build. Note also the sheer stringer doubler shown here under the stringer at the position of the beam blocks. These teak doublers provide a place to mount the square plywood lashing pads at each beam lashing location, and become the bearing surface the lashings contact when the turns are made under the plywood pads.

Tuesday, May 20, 2008

Sheathing Decks and Cabins

The photo below shows the upright hulls after all four decks were sheathed with Xynole polyester cloth.

On the starboard hull, shown below, you can see the fairing compound applied with putty knives, over the sheathing. This build-up allows sanding everything smooth without danger of getting into the weave of the fabric.

This last photo shows the aft side of the starboard cabin, with sheathing applied. Vertical surfaces like this require lots of fairing as the epoxy wants to sag before curing.

Monday, May 19, 2008

Priming and Bottom Paint

We're moving forward with project much faster than the updates here indicate. Lots of priming and pre-finish work has been done on various parts. Below is the mast with primer coats completed.

On the hull we applied three coats of Interlux barrier coating, beginning with the gray seen to the left and progressing to a lighter gray and then white.

Bottom paint was then applied below the chine knuckle. We used Petit's Vivid bottom paint in the white color. The topsides above the chine will be painted with red Awlgrip.

This bulge in the inboard side of the starboard hull, below the waterline, is a custom made mounting for the fathometer. The transponder needed to be pointing down and with the hull shape of the Tiki 30, it was necessary to build in this wedge-shaped hollow mounting space to accomodate it. The other hole is the thru-hull for the knotmeter.

The following photos show the crew turning the hulls back upright. With the bottoms done and topside panels ready to paint, we will not have to invert the hulls again.

Moving forward from this point will begin with sheathing the decks and cabin structures with Xynole cloth.

Thursday, May 8, 2008

Sheathing and Fairing

With both hulls fully sheathed with Xynole polyester cloth, we have now proceeded with the fairing and priming processes. Below is the port hull after the sheathing was completed.

Fairing begins with filling the weave of the cloth with more coats of epoxy, thickened with phenolic microballoons and silica. This mixture creates an easy to sand surface with minimal sags and runs.

The fairing process continues with low spots being filled to the same level as the rest of the hull and then sanded fair using a batten to determine what needs more filling or sanding.

Below you can see the port hull, along with one of the crossbeams, now with a first coat of primer applied.

The mast case built onto the mast beam is also in the process of fairing, and all the intricate surfaces had to be sheathed the same as everything else.

Below is the mast beam, sheathed and faired, almost ready for primer.

Here are the three complete beams, primed and almost ready to paint. We will also build a forth, smaller beam for a rear netting beam, but it will be a simple hollow spar section of Douglas fir rather than a complex triangle section like the main beams.

The mast that Scott Williams built last week has also been finished sanded to a perfectly round section and coated with epoxy.

Sunday, May 4, 2008

Shaping and Prepping the Hulls for Sheathing

(Posted by Scott B. Williams)

I'm back home in Mississippi now after working for 9 days on the Tiki 30 project. So much progress was made while I was there and since I left on Wednesday that updates here are way behind. This post and the one following on the rudders will detail some of the other phases of the project that were going on while I was there to build the mast. After this, David will be taking over again with new photos of what has happened since I left.

When I first arrived back at the shop to begin the mast, the hulls were still outside under a tarp, as they had to be moved out of the way until the interior for the Liberty 42 Sportfishing Yacht was returned to the rear of the shop for finishing. David had built a small, low cart with 6 wheels for moving the hulls. This method works fine when you have enough help to manhandle the hulls onto their sides.

The cart was padded with heavy blankets and the hulls laid over on it, one at a time to be wheeled back inside the shop. The Tiki 30 hulls are much heavier than my Tiki 26 hulls. Once you get into this size range, moving the hulls requires either a lot of muscle or mechanical aids, or both.

The hulls were set up in the inverted position on custom-built, super-strong sawhorses David had the crew build. This was necessary to begin the process of shaping and fairing the keels, skegs, chines, and stems and filling screw holes in preparation for sheathing.

Here you can see the starboard hull with all this filling and shaping work going on.

After the keels and skegs were shaped to a smooth, rounded surface that will cut quietly through the water, they were reinforced with heavy layers of triaxial fiberglass cloth in the areas of possible impact and abrasion damage.

Here is a profile view of the keel on the port hull, reinforced with the triaxial cloth.

Below the starboard hull is ready for sheathing. David decided to use Xynole polyester cloth for this, rather than fiberglass. This decision came about after we made another trip to Ft. Pierce to visit with boat designer and builder Reuel Parker, who uses this material for sheathing on all his boats. This fabric is tough, lightweight, conforms around corners easily and provides great impact resistance. Parker describes its use in detail in his book: The New Cold-Molded Boatbuilding: From Lofting to Launching

David and I made another trip to Ft. Myers on Wednesday before I left and visited the Raka Epoxy warehouse, where he bought enough Xynole cloth to sheath all the exterior surfaces of the boat. His crew is so well organized that he called them from the truck while we were driving back, instructing them to begin pre-coating the hulls, so that when we pulled up the cloth was immediately rolled out and applied to the wet epoxy. As I was leaving the first hull sheathing was done.

Other parts that were sheathed and finished while I was there were the front and aft crossbeams. These were covered with 6-oz. fiberglass, as this was done before the visit with Reuel Parker. The beams came out really nice and will look great when painted.

Preparing the Rudders and Laminating Tillers

Another project I worked on while I had drying time on the mast parts was preparing the rudders for installation by giving them the treatment I devised for my own Tiki 26 rudders. I wanted to insure that the holes drilled for the rudder lashings would never allow water to penetrate the plywood and lead to rot, and David liked my method so he asked me to do it to his rudders as well. Photos and descriptions of this process on my Tiki 26 rudders can be found here.

The process is easier if you do it before the hulls are assembled, when you can match the skegs up with the rudders and drill all the holes on a drill press. Since David's skegs were already in the boat, they had to be done in a different fashion but it was still possible. The rudders were easier, as shown in the steps below.

First an oversized slot was cut in the position of each set of lashing holes. This was done by first drilling three 7/8" holes in a straight line and then cutting out the material between them with a jigsaw.

These large holes were filled with epoxy thickened with chopped fiberglass strand and silica, then the leading edges of the rudders were routed out to allow for teak inserts to be glued in where the rudder lashing will cross over in the attachment to the skegs. These hardwood inserts will also help prevent water entering the plywood edges. Below Pascual is using a template to route consistent-sized openings for the inserts.

This photos shows his template set-up and some of the routed openings. Pascual is David's top guy with router set-ups and custom templates, and he loves doing this kind of precision work.

Below you can see the rudders with the teak inserts installed, and the plywood template I made for drilling the holes. Pascual also made another router template to recess the area around the lashings 1/8" deep in relation to the surrounding rudder surface. This will keep the lashings lower in profile and reduce turbulence in the water.

This photo shows the finished insert work done, with the lashing holes drilled using the template and the sharp edges of the routed recesses filleted with epoxy to allow sheathing over the whole surface. All that remains to do on the rudders is shape the edges to a hydro-foil section as the plans show and sheath them.

The tillers were also laminated while I was there. David has lots of extra teak on hand so he built them of teak and used a simple form on a work bench to glue them to the curved shape, as this allows more control than the weighted method shown in the plans.