Monday, May 26, 2008

Reinforcing the Keel

I'd been pondering for quite sometime the various options for building up the keels of my Tiki 26 to reinforce them for occasional intentional beachings and inevitable unintentional groundings. Most Tiki 26 builders add some kind of keel reinforcing strip, sacrificial wooden shoe, or strip of metal or PVC plastic. The problem with some of these add-on materials is they often requires screws penetrating into the glassed-over keel to hold them, or they are glued on with epoxy or bedding compound but can eventually work loose. The other problem is that it would be difficult to keep bottom paint on a metal or plastic surface, and difficult to fair it in to the rest of the hull for a smooth entry through the water.

To keep it simple, I decided to use 1708 fiberglass tape, a heavy biaxial fabric with a mat on the inner side. This thick tape, in the 6-inch width, holds a lot of resin and will add a very strong layer of protection to the keel. It may eventually wear down from abrasion, but that will take a long time, and it can be easily replaced. I don't plan on much beaching and when I do nose the boat up to the shore it will only be for brief visit as I always anchor off for any extended stay or if there is a sea running.

This tape is so thick it is necessary to first wet it out completely from the inside before applying it to the hull. I did this on some scrap plywood panels shown below. I also sanded, cleaned, and coated the keel area of the hull with wet epoxy before laying the tape on.

Here, you can see the 1708 tape in place on the keel. Since it reaches 3 inches up on either side of the keel, it provides additional strength all along the bottom, which could help if I ever find myself aground on a reef or rocks.

Fairing this stuff into the hull is quite a job. After laying down the tape strip and making sure it was completely wetted out with pure epoxy, I went back over it with a first layer of epoxy thickened with microballoons and silica. This was applied with a drywall knife, but is still thin enough to fill the weave well. As you can see, more epoxy putty will be needed. The next round will be thicker to build up a deep enough coating to sand it smooth.

I plan to go ahead and turn the port hull over again as well, to give it this same treatment. I will then fair and prime both hulls before proceeding with the decks and cabins.

Monday, May 19, 2008

Sheathing the Starboard Hull

My plans for attending the Florida Wharram rendezvous changed when I decided that my truck would likely not be capable of trailering home the trimaran I was going to Florida to bring back here for a repainting job. I decided to pass that job on to my friend, David, and his crew at Boatsmith. So, with the cost of fuel being what is is, driving almost 2,000 miles to Islamorada was less appealing. Instead, if they have a summer rendezvous there this time next year, I plan to sail there on Element II.

Staying home had it's benefits, as the weather was perfect for fiberglassing. I got one side of the starboard hull sheathed yesterday and will do the other side today. As with the port hull, I found it easier to do this with the hull suspended and laid over on one side, so that I'm not fighting epoxy runs as I work alone wetting out this fairly large area.

Lots of sanding was required first, smoothing out the fairing compound I used at the transition of the keel and stem and skeg where I added extra layers of fiberglass a few days ago.

Here the dry cloth is draped on the hull in one piece. I bought 18 yards of this 50-inch wide cloth just for this purpose when I visited the Raka Epoxy warehouse in Florida last month.

Wetting out the cloth went smoothly and was easy to keep in control, as I worked from the bow back, pushing out trapped air and smoothing the cloth with a rubber squee-gee. I used slow hardener for this, again since I'm working alone and need the extra time.

After the cloth was saturated, I waited a couple hours and applied a second coat of epoxy (not shown) using a mix of phenolic microballoons and silica to slightly thicken it and fill the weave. This coat was done with a medium fast hardener, and by evening yesterday it was cured. Today I'll trim the excess cloth on the edges and sand the transitions, then roll the hull over in the slings and do the same for the other side. Other work that has been going on while waiting on epoxy to cure includes gluing on teak sheer doublers at the beam locations on the port hull and making the lashing pads. I've also applied another coat of paint in the forward hold of the port hull and a coat of varnish in the forward part of the cabin under the foredeck.

Thursday, May 15, 2008

Florida Wharram Rendezvous

I'm heading to the Florida Keys tomorrow, just in time to make it to the Florida Wharram rendezvous in Islamorada by Saturday. I had not expected to make it to this event, but another job opportunity involving transporting another multihull back here for refinishing will put me in the area anyway, so I might as well attend.

I'm looking forward to meeting other Wharram enthusiasts - both sailors and builders - and for the opportunity to see a range of Wharram sizes and designs I have not yet seen in person. My friend David will be there with his family, though the Tiki 30 is not ready to show as he had hoped. But he is bringing a really cool dinghy he just built that should be of great interest to Wharram sailors. This boat is a 14-foot Reuel Parker designed periagua - a slim, lightweight and good looking rowing craft that will fit easily across the decks of most Wharram designs from the Tiki 26 size and up.

If any of the regular readers of this blog are planning to be at the rendezvous, I look forward to meeting you.

Nissan Outboard

Fiberglassing the starboard hull this week didn't happen as planned. Yesterday, I went to Mobile, AL to purchase a slightly used Nissan outboard that will be the auxiliary engine for Element II. This is the exact model I had planned to purchase new: the 6hp, 4-stroke with extra-long 25-inch shaft and built-in charging alternator. It will be the ideal power source for a Tiki 26, as it is lightweight, at only 60lbs. and will push the easily driven hulls quite economically.

I had the 5hp model on my Tiki 21, Element, and it performed flawlessly. I recommended the above model to Thomas Nielsen, when he was building and outfitting Tsunamichaser and he as been well-pleased and satisfied with the performance and agrees it is ideal for this boat.

This particular engine was only used a couple of hours by the previous owner, who had fitted it into the outboard well of a Pearson Commander that he subsequently sold. The discoloration on the shaft and foot is anti-fouling paint he applied as the engine could not be tilted clear of the water on that particular boat. This turned out to be a great deal and I'm looking forward to the day I'll get to try it out when I launch Element II - thanks again, Jerry!

The other thing that disrupted my plans to get my starboard hull glassed was a phone call that came while I was still in Mobile, and an opportunity for work transporting a Farrier trimaran back here from south Florida for repainting. The good thing about this opportunity is that the timing works out so that I can make the Florida Wharram rendezvous in Islamorada this weekend. More about this in the next post....

Tuesday, May 13, 2008

Keel and Skeg Reinforcements

The first task I'm facing this morning is a dusty one - sanding the entire starboard hull that is now almost ready for fiberglass sheathing. Yesterday I completed the keel, stem and skeg reinforcements. I did this by taping off a few inches above the keel on either side and laminating 2 layers of fiberglass cloth over it. This was carried out to the aft edge of the skeg as well to strengthen the joint where the skeg exits the hull panels.

The keel reinforcements were done in two steps, with the second layer over lapping the first by a good 2 inches.

After the epoxy cured enough for the edges of the fiberglass to be cut and the masking tape removed, I applied a layer of filling compound made by mixing epoxy with silica and phenolic microballoons.

This first filling layer is now ready to sand this morning. I've also used the same mix to make small fillets at the topside chine joint and the bottom edge of the topside stringer. After sanding completely, there will likely be additional filling needed in places to get a smooth enough surface for wetting out the fiberglass on the entire hull.

Here's a view from the bow showing the filling around the stem. If the sanding goes well and the second layer of epoxy cures fast enough, I may get one side of the hull sheathed today.

Friday, May 09, 2008

Sheathing the Crossbeams

I've spent a considerable amount of time this week on a task that is quite tedious and doesn't show a lot of progress for the amount of labor involved - that task is sheathing the crossbeams with fiberglass. This is a necessary step, I believe to insure longevity in these essential structural components of the boat, but the way they are designed is certainly not conducive to covering in fiberglass.

I just returned from Florida last week where I was working on David's Tiki 30 and as I've mentioned here before, there's quite an improvement in beam design on the newer Tiki 30. The difference is all the solid stringers are inside the plywood panels, creating a closed triangular box section that is easy to 'glass. The Tiki 26 beams, on the other hand, are a fiberglass lay-up nightmare, requiring hours upon hours of prep work and sanding the fillets smooth, then applying the glass in partial segments that can wrap around all the exposed edges. In retrospect, if I had it to do over again I would build scaled down Tiki 30-style beams for the Tiki 26 just because of this issue. Nonetheless, the beams I have must be sheathed, and that is what I'm doing. Structurally, they are just as sound in design as the newer beams, so once this job is done I won't worry about them.

In the first photo you can see the aft beam with the top plate covered in wetted-out 6-oz. fiberglass. I used tape lines like the one at the top of the fairing to cut the fiberglass in straight lines. This layer slightly overlaps the previously applied layer that covers the front fairing.

In order to be able to wrap the fiberglass fabric around the corners, I used a router to cut all the corners to a 1/2" radius. The beam on the left is the aft beam again, showing how the glass wraps around the top plate to the upper part of the vertical plywood web.

Below is the aft beam again, now with all exposed surfaces sheathed. The fabric makes a lumpy mess in places - hard to avoid with so many overlaps. In the photo below this has been faired out with a skimming compound of epoxy mixed with phenolic microballoons and silica. It will take some work, but when the beams are all sheathed and all surfaces faired and sanded smooth, they will once again be smooth and beautiful and will look great when painted.

Shaping the Rudders

I've spent so much time sanding and fairing fiberglass this week on the crossbeams and doing paint and varnish prep work on the Backwoods Drifter I'm finishing up that I had to have a change of pace for an hour or so this afternoon.

I got out the rudders that I had been storing in the house to keep them from warping and using the belt sander and my 6-inch random orbital disc sander, shaped aft edges to the foil section as specified in the plans. This was pleasant work and the shape came out well. The next step will be sheathing these and hopefully one day soon, hanging them on the sterns of the two hulls.

Shaping the rudders begins with removing material with belt sander first, then smoothing with the disc sander. The glue lines between laminates in the plywood help maintain consistency in material removal.

This weekend I will get back to the hulls. While in Florida I visited the Raka Epoxy warehouse and bought the fiberglass and epoxy necessary to sheath the starboard hull, which is upside down and ready. Hopefully that will get done this coming week. I've also found a great deal on a practically brand new Nissan outboard motor for the boat and will probably pick it up in Mobile, Alabama one day next week. It's the exact model I planned to buy anyway - the 6hp 4-stroke extra-long shaft with built-in alternator - and it only has 2 hours of run time on it.