First Coat of Bottom Paint

I rolled on the first coat of bottom paint on both hulls yesterday, after sanding the final barrier coat of clear epoxy to 80 grit and washing with soap and water to remove any trace of blushing. I was quite pleased with how the hulls below the waterline turned out. They are fair and smooth, and the Petit Vivid bottom paint was pleasure to work with, much better than any other anti-fouling paint I've tried. I took it to my local hardware store and had a friend who works there put the gallon can in their automatic paint shaker, and when I opened it I found it just the right consistency for rolling. The color coverage was good, as you can see in the photos. This is just one coat.

One coat took less than a quart of paint. I guess I bought too much, buying a whole gallon, but it's cheaper to buy a gallon than three quarts, and I was afraid two would not be enough. At any rate, I'll have more than enough to do three coats before launching and if the shelf life is any good at all, enough for the first bottom job a couple years later.

The plan now is to finish fairing the hull topsides from the waterline to the sheer, and then to get primer and a first coat of topside paint up to at least the topside chine overlap. When this is done, I'll put a second coat of bottom paint on before turning the hulls right side up. The third coat will be put on when everything is finished, shortly before launching.

Beam and Shroud Lashing Cleats

With both hulls turned back upside down, my goal now is to finish everything from the sheer down so that I can paint the bottoms with anti-fouling and prime and first-coat the topsides with paint. The reasoning behind this is that all the details that are easier to do upside down will be completed, eliminating the need to invert the hulls again, so that once I turn them right side up, I can focus on the cabin interiors and deck structures.

The beam and shroud lashing cleats, or pads, are part of those details that are easier to complete with the hulls upside down. The reason for this is that it is essential to completely seal the undersides of the lashing surfaces created behind the cleats. This is a common source of rot in the smaller Tiki designs.

Below are all the lashing cleats - a total of 12 for the beams, inboard and outboard sides, and 4 for the shroud lanyards. I had planned to install chainplates instead of these lanyard pads for the shrouds, as is shown on the Tiki 30 plans and as the previous owner of my Tiki 21 had done. In the end I decided to stick with the simpler and practically free way of attaching the shrouds that is shown on the plans. Four chainplates of adequate size and strength plus the four shackles required to attach them would have been close to $300. That cash can best be spent elsewhere on the boat. Wharram's methods of eliminating such expensive hardware are brilliant.

Yesterday I installed all the beam and shroud cleats, gluing them well with epoxy and using temporary screws to hold them until the epoxy cures. The screws will be removed and replaced with 1/4" stainless carriage bolts after the cleats are faired and ready to paint. The thru-bolts pass through the extra layer of plywood backing already glued on the inside of the hull at each lashing point. They will be secured with large fender washers and self-locking nuts.

Here is a close-up of one of the lashing cleats, taken this morning after an initial coating of epoxy. Each plywood pad is made of 18mm ply and all corners are rounded and the edges are radiused to 3/8" so there are no hard edges exposed. The next step is to round over the bottom edges of the teak sheer doublers on either side of each pad. Small fillets of epoxy with wood flour and silica will be made on each side where the pad meets the doublers and sheer stringer, and a small fillet will be carefully made and smoothed on the inside edge of the pad. This is why it is easier to complete this job with the hull upside down. All surfaces in contact with the lashing lines must be as smooth as possible, as well as completely sealed from water intrusion. Sheer doublers made from solid teak will help greatly in preventing rot in this vulnerable area.

When all these lashing areas are completely faired, sanded smooth, and sealed with epoxy and primer, I'm going to thoroughly wash the hull exteriors and apply the bottom paint below the waterline. The first coat of topside paint can also be applied up to the bottom edge of the sheer stringer. The stringer itself will remain bare until after the decks and cabin sides go on, as I plan to wrap the fiberglass sheathing from the deck surfaces around the stringer to give a double layer of protection to the sheer and reinforce the deck to hull joint.

Starboard Deckbeams

The hull bottoms were finished last week up through the final fairing and sanding, and then barrier coated with a clear coat of epoxy to ready them for bottom paint. Next week I will pick up the bottom paint, a relatively new product from Petit, called "Vivid." This is a bottom paint that can be applied at any time during the construction, as it is formulated for boats that are sometimes stored out of the water and does not lose its effectiveness when dried out like most bottom paints.

In the meantime, with nothing left to do to the bottoms until I get the paint, I turned the starboard hull back upright to begin the process of fitting out components like deckbeams and other parts needed to get it to the same stage as the port hull. This is going much faster than on the first hull, as all these parts were either already cut or at least marked out on the wood they would be cut from when I made the first set for the port hull. Below you can see the five deckbeams; cut, sanded, and epoxy coated prior to installation:

The beams were epoxied in place leaving the un-trimmed bulkheads protruding above.

When the epoxy cured and the clamps were removed, the excess bulkhead plywood was trimmed with a router, using a flush cutting bit to follow the curves and notches of the deckbeams.

Another project on the starboard hull was gluing on all the sheer stringer doublers at the beam landing locations. These are made of teak and were also cut out while making the set for the port hull.

Many other tasks are also underway as the epoxy cures on these parts, mostly filling and fairing inside, cleaning up the fillets and prepping the forward storage and buoyancy compartments for primer and paint.

Marking the Waterlines

I spent most of yesterday morning setting up a water level and marking the waterlines on both hulls. This is a project I wanted to get done while in the fairing process, as the hull surfaces below the waterline will be covered with a thicker anti-fouling paint and therefore to not have to be sanded to perfection like the topsides that will be painted a high gloss.

A simple, jury-rigged water level is the most accurate means of establishing a true waterline on a boat hull. I bought 35 feet of clear plastic tubing with and I.D. of 3/8." Total cost: 8 dollars and change. This is better than an expensive laser level that can't "see" through the hulls. A water level allows you to mark all sides of the hulls all the way around in one set up. Wharram's plans for the Tiki 26 include a sheet with waterline measurements, showing the height of the bow and the height of the stern (both at the sheer) above the waterline. These measurements are vertical distances above the water, however, and cannot be measured on the hull. Since my hulls are currently upside down, what I had to do is establish an arbitrary waterline at a level within the range I could hoist or lower them with slings. I marked this line on a clean piece of wood taped to one of my shed support posts, as shown below. I then marked the distance from the waterline to the bow and to the stern by measuring vertically from the arbitrary waterline mark. Since the hulls were upside down, this meant measure down from the line - 31 5/8" for the bow, and 25 3/4" for the stern. I then adjusted this for the maximum load waterline by subtracting 3 inches from these numbers.

The water level consists of nothing more than a bucket of water and the clear hose. The bucket is filled, then lifted up with the hose on the ground and one end secured inside the bucket below the waterline. The hose is filled by starting a siphon until the water flows freely from the open end. Then the open end is picked up and held higher than the bucket to prevent air bubbles in the line. The water level is now operational, and the water in the hose will match the waterline in the bucket.

I started by taping the hose to the side of my marked pole. Then I lowered the bucket until the water level in the hose matched exactly the mark for the bow. The open end of the hose was then moved to the first hull, and using my webbing slings I lifted the bow until it matched the waterline in the hose, and of course, the marked line on the pole. This was repeated for the stern, adjusting the bucket to the mark for the stern. It took a couple of back and forth operations to get the hull exact, bow and stern, then I leveled it athwartships by crawling under it with a spirit level and blocking it in position with scrap wood. With the bow and stern now the correct height above true waterline, I then readjusted the bucket until the waterline in it matched the marked waterline on my pole. When this was done, all I had to do was take the free end of the hose to the hull and make marks all the way around both sides about every foot or so. The marks were then connected by carefully pulling a line of masking tape through them. I masked above the marks, so I could paint a swath of dark gray primer above the actual waterline, then remove the tape and still be able to see it clearly.

In the first photo below, the bucket is set at the height of the waterline and the clear hose standing vertically against the hull in the background is being used to transfer the marks (already painted in this photo).

Here's a view from the bow showing the port hull with waterline marked with primer. You can also see the side of the starboard hull to the left. The other hull in the top right of the photo is a 19-foot woodstrip canoe I built years ago and have no where else to store. It's somewhat in the way, but hopefully it won't be long before I'm pulling the Tiki 26 hulls out in the open for assembly with the beams.

Another view of the starboard hull shows the straight waterline, with gray primer above. This line is 3 inches high to accommodate a fully loaded boat. Waterlines are always optically deceiving viewed like this and do not usually look straight when the boat is upside down. But using a water level is fool proof and the boat will sit on it lines when launched if the numbers given in James Wharram's plans are correct.

Bottom Jobs

After laminating the 1708 biaxial tape onto the keel of the starboard hull, as described in my last post, I turned port hull upside down as well to give it the same treatment. I decided at this point to go ahead complete all the work on the bottoms of both hulls, all the way through painting the anti-fouling below the waterline. That way I won't have to turn them back upside down when the decks and cabins are completed and the hulls are much heavier.

Below you can see the fairing process of building up thickened epoxy to smooth the transition between the heavy 1708 tape and the rest of the hull surfaces.

In addition to the bottom of the keels, I also laminated the 1708 tape around the leading edges of the skegs and around the stems all the way from the keel to the stem heads above the deck. This will provide a degree of protection if I should hit some floating object in the water, or bump the bows against a concrete dock as I did once with my Tiki 21.

This heavy biaxial tape conforms easily around a tight radius like the stem edges, but requires a lot of filling and fairing to blend in the transitions.

Here you can see the tape with the first fill layer of epoxy mixed with phenolic microballoons and silica. This thickened layer was brushed on to fill the weave completely. The subsequent fairing layers were applied with drywall finishing knives.

In the photo below you can see that most of the transition has been faired. There is still some minor filling and more sanding to be done, but once it is complete the biaxial tape will be indistinguishable from the rest of the hull sheathing.

I'm closing in on the fairing, as shown below, but there is still more minor filling and lots more sanding to do to get the hulls ready to paint.

It's summertime in Mississippi now and at least 90 degrees in the shade every day. Sanding and fairing the hulls is hot, dusty, and monotonous work. This part of the project is probably the least fun aspect of building a boat, but I'll soon have it behind me and will be moving on to more interesting phases like completing the decks and cabins.