Monday, April 30, 2007

Bunk Access Hatches

I'm making the bunk access hatches a bit smaller than is suggested in the plans, mainly because I wanted a continuous web of bunk ply attached to the hullsides, rather than having entire sections lift out. As Thomas Nielsen has said on his blog, these bunks are a great opportunity to strengthen the hull in this area. I'm not using quite the elaborate latching access hatches Thomas has divised, but the bunks will be one continuous web, and each opening is reinforced with an athwartship bearer that goes from hullside to hullside, and longitudinal supports between these for the hatch lids to rest on. The hatch lids themselves will simply drop into position on these bearers, with a fingerhole in each for easy removal.

I should be ready to install the two forwardmost bunk sections in my next work session later this week.

Forward Buoyancy Compartment

Here's a look into the forward watertight buoyancy compartment. The area between the diagonal stringers is reinforced with a ply web, as shown in the plans. The inside edge of the stem is deeply buried in a large fillet of thickened epoxy, with 3 overlapping layers of glass tape over it. A waterproof inspection hatch will be fitted in the hole cut in bulkhead 6. I don't plan to put any fixed foam floatation in any of these sealed compartments, as many Wharram owners have found this can lead to rot. I also want to be able to get to the inside of the hull at any point, in case of damage that needs repair from the inside. I'm thinking of filling these compartments with empty plastic soda bottles, each one sealed tightly with the cap. These can be packed in through the 6-inch inspection hatches one by one, and removed the same way if access is needed. Filled with air, dozens of these bottles in each compartment would provide lots of positive floatation in the event of a holing.

Finishing up Below Bunk Level

Most of the work in the starboard hull below bunk level is now completed, with the exception of the area under the bunk aft of the companionway. Since I did not install any floor section in this aft section, there is less work to be done there and I will get to it after the main bunk sections are in place.

Finishing up involved sanding fillets smooth and building them up in rough areas, then applying fiberglass reinforcement over the floor to hullside joints. I'm not using any pre-cut fiberglass tape, as the finished edges of this kind of tape are hard to fair into a bright finished surface. Instead, I'm cutting all the tape strips diagonally from a roll of 6-ounce fiberglass cloth. The trick to getting almost invisible edges on the fiberglass is to use masking tape as shown in the photos below.

Before applying any glass cloth or resin, masking tape is first laid down to define the edges of where the glass needs to go. The fiberglass is then smoothed down in position while still dry, and then enough resin is brushed on to wet it out to the edges of the masking tape, and excess resin is removed with a squeegee. This first wet-out application of epoxy is then allowed to partially cure. The trick is to time it just right, so that it is sticky enough that the glass cloth is not easily pulled away from the surface in the areas where it needs to be, but the tape and the overlapping edges of the cloth can still be removed. When it reaches this stage, in about 2 hours in the 80F weather we've had here lately, I use a razor blade to cut the cloth just inside the edge of the blue tape. The tape can then be pulled neatly away, and a second coat of epoxy applied while the first coat is still tacky.

To get the final finish as it will be left in these under the bunk areas, I lightly sand the glass cloth, especially the edges, a full day after the first two coats of epoxy have cured, and then apply a third thin coat. The photos below show the result in the areas between bulkheads 4, 3, and 2. Above the bunk level, which will be finished the same way, I'll also apply 2-3 coats of U.V. inhibiting spar varnish to protect the epoxy from sunlight.

Monday, April 23, 2007

Floor Panels Installed

I had some unexpected free time this past week so I was able to put in quite a few more hours than my average lately. Most of what I'm doing at this stage is time-consuming without much visible progress, such as finishing out the keel fillets, applying layers of fiberglass over those, sanding and working the bulkhead fillets smooth, and generally finishing everything up below the bunk level in preparation for installing those. The Tiki 26 plans specifiy a small floor panel between bulkheads 2 and 3, in main cabin area where the companionway is located. This area below bunk level is a "wet locker" and footwell, allowing crew to sit and do chartwork or cook a meal or whatever. Some Tiki 26s I've seen have a loose fitting, removable board here, and others are sealed and watertight. I wanted a solid surface to step down on, but with an easily removed panel so every area of the hull can be inspected and the space below the floor can be used for storing small items.

Since I raised my bunk level by 3 inches, this floor level was also raised by the same amount, making it a good bit wider and with more space under. I decided that such a partition as this floor would also be useful in the next section forward, between bulkheads 3 and 4, and this would also serve to strengthen the lower part of the hull where I might have lost some stiffness due to moving the bunks up. I find in my Tiki 21 that the large V-shaped areas are awkward for storage, and stuff moves around unless packed in tight, so a partial floor would keep larger bags and containers up out of the V bottom, but still allow lots of small items such as water containers, canned goods, etc. to go into the bottom. I was concerned about adding too much extra weight with this additional floor, so I cut away two large access holes so that it now becomes more of a stiffening web, like a longitudinal bulkhead. Filleting the edges to the hullsides will add great strength but the amount of extra ply is minimal. I made another short section like this to go just forward of bulkhead 4, as Thomas Nielsen has done in his Tiki 26. This may be used as a battery-mounting shelf, as Thomas is doing, unless I decide later to mount the batteries elsewhere.

The photos below show these floor panels. In the first one you can see the underside of the one between bulkheads 3 and 4. It's the one with the two openings and the stiffener glued across the middle. The smaller panel to the right is the one that goes forward of bulkhead 4. In the foreground is the main panel that goes between 2 and 3, with the bearers for the removable panel being glued in place.

Floor panels installed. Looking aft to bulkhead 2, you can see the main floor with the removable panel in place, and part of the added floor forward of bulkhead 3.

This is the floor panel between bulkhead 3 and 4. There is a lot of space below the panel, and still a large volume of storage above this floor and under the bunks.

Here is another view looking in at bulkhead 4. You can see the short panel forward of bulkhead 4 here.

And this is the compartment between bulkhead 4 and bulkhead 5. This would be a good place to locate a battery, to keep the weight low and forward, since so much other heavy stuff such as the engine and its fuel has to be located further aft.

As you can see from the photos, I have not finished the fillets around these panels. I still have to sand them again and make the final pass over them to smooth out imperfections, then apply another clear coat of epoxy over the fillets and everything between the floor level and bunk level. The bunk panels are all cut and fitted, but I still have to make and install the bearers for the access hatches in them. I have to leave town again for a few days this week to work, but hopefully in a few more boatbuilding sessions, I'll have the bunks installed.

Another Tiki 26 on the Gulf Coast

I was on the coast for a couple of days last week, for a book signing in Pascagoula, and a day of sailing on my Tiki 21, Element. The turnout at the book signing was not great, and the wind was light and variable the next morning when I went sailing. But the interesting part of the trip was that I discovered another Tiki 26 that was built right here in Mississippi that I had no knowledge of. A friend had emailed me a couple of times, saying he had seen a Wharram in the area, so I drove along a riverside road where he thought it might be docked, and sure enough, it was a Tiki 26. I stopped and took photos, then got the owner's phone number from the owner of the dock it was tied to, and talked to him a couple times on the phone. He said the boat has been finished for about a year, and he was unaware of my Tiki 21 or other Wharrams in the area. I'm looking forward to meeting him and seeing the boat again in the near future. He said it sails really well and he frequently takes it out to the barrier islands. Below is one of the photos I took when I first spotted it. It is built to plan and I like the simple, workboat finish that blends right in with the local commerical fishing craft and fits the Wharram philosophy so well.

Tuesday, April 17, 2007

The First 100 Hours

Bunk and floor panels for the port hull, coated on the underside with epoxy.

I just reached the 100 hour mark in the construction of the boat yesterday. It's been 12 weeks since I bought the first materials, so this puts the average at only 8.3 hours of boat work per week. Although this is far less time than I would have liked to devote to the project, I'm pleased with the amount of progress and feel that most of this time has been used efficiently in order to get this far. With summer approaching I will soon have much more time to put into the boat and hopefully some full time weeks here and there. I've been working out of town a lot so that prevents getting in even an hour or so in the evening after work.

I just finished cutting out all the bunk and floor panels and getting the first coat of epoxy on those in preparation for installation. While working on these panels, I'm also finishing up the keel and bulkhead fillets so that everything below bunk level will be complete before they go in. I've also coated and installed all the longitudinal bunk bearers I mentioned in the previous post. These will make the actual installation of bunks go faster.

I'm sure the building of the second (starboard) hull up to this point will be much faster with all the patterns already made for the bunks and floor panels. And, of course, all the hull panels, bulkheads, and the stem and sternpost are completely finished, coated, and ready to go. I'm still trying to decide at which point exactly I want to begin assembly of the second hull. I know I want to at least finish all the bunk fillets on the first one, because after this point the hull will be stable and a solid unit that cannot get out of alignment. I may continue on to the installation of the topside hull panels, and possibly even turn the hull and fair and glass the bottom. But I don't want to get too far ahead on the first one so that it feels like I'm starting all over again when I build the second hull.

Monday, April 09, 2007

Adjusted Cabin Height

Here are the missing cabin top sections that belong on bulkheads 2, 3, and 4, as it may have been obvious in some of my previous photos that these bulkheads were cut off straight a short distance above the sheer level. I separated these upper sections deliberately in the bulkhead layout phase, knowing I would have to compensate for my raised bunk modification. In the photo below they are temporarly clamped into position, but when I am ready to set the height and put them permanently in place after the hull is complete to sheer level, they will be put back on in the same manner the hull panels are joined together. The opening in bulkhead no. 3 will be cut much higher after these are rejoined and the cabin is built.

Bunk Bearer Installation

To aid in alignment and to eliminate the need for large epoxy fillets below the bunks where they join to the hullsides, I decided to make lightweight longitudinal bunk bearers to support the edges of the bunk sections. I cut these to the same dimensions as the diagonal stiffeners that are also epoxied to the hullsides, and then cut the top surface upon which the bunks will be glued to a bevel to match the tops of the athwartships bunk bearers that are glued to the bulkheads. Again, this is a method used in the construction of the Tiki 30, but is not suggested in the Tiki 26 plans. The main advantage is the ease of keeping the bunks level, but eliminating the large underside fillets is also a time saver and the joint will be just as strong with the large fillets on the top side where the bunks meet the hull. Shown below is one of these bearers in the main cabin area between bulkheads 2 and 3. The bunk section is moved aside for clarity.

Here is a view of these longitudinal bearers from aft of bulkhead no. 2. The rough pattern for the floor section between no. 2 and no. 3 is also shown.

All these bunk bearers are cut and dry fitted. In my next work session I will radius the bottom edges, coat them with epoxy, and glue them into place using temporary screws. In the meantime, there is still much finish work to do on the bulkhead and keel fillets, but these will be done by the time the bunks are cut, reinforced and coated for installation.

Making Bunk Patterns

Today I worked on the layout and alignment of the cabin bunks in the port hull. Some slight adjustments in the bearer height at bulkhead number 3 were in order, but overall the alignment went well, despite my modification in raising the bunk level 3 inches as described in an earlier post. In order to see exactly how I wanted to place the access hatches to the below bunk storage, and to make this job easier when building the second hull, I made patterns out of cheap 5mm luan ply, which is stiff enough to hold it's shape with the hatches cut out. As shown below, I did have to weight it down in the corners in some places to keep it flat, but it will work good to transfer the shape of the bunk boards to the 9mm Okoume ply they will be made of.

Below is a view of two of the access hatches, looking into the bulkhead no. 4 area, in the bunk area at the forward end of the cabin. I think Thomas Nielsen had a good idea about strengthening the hulls at the bunk levels by not cutting the access hatches all the way to the hullsides as shown in the plans. Although I am not planning to use the elaborate latching system he has used on his excellent bunk hatches, I did decide to leave a continuous web of ply that can be filleted and glassed to the hullsides. The underside of these openings will be reinforced with solid wood stringers that will also serve as bearers for the hatch boards. This style of hatch is specified in the plans for the Tiki 30, but in the Tiki 21 and Tiki 26, the hatch sections are simply cut away all the way to the hullsides.

Below is a view of the bunk patterns and hatch cutouts looking aft from just ahead of bulkhead no. 4.

Monday, April 02, 2007

Diagonal Stringers and Bulkhead Fillets

I took this photo last night after a day of working on keel and bulkhead fillets. It's hard to get a photo of the entire hull with it inside the shed, as there is not much room around it. The building space seems to be working out well though. I've got room to get to everything without too much contortion, but there will be less room for large tools such as the table saw and extra materials when I begin assembly of the second hull. That will still be a few weeks away, as I am once again working out of town and will be away from the boat a few days each week. I managed a half a day Saturday and most of yesterday though, allowing me to fit and install all the diagonal stringers, and make the beginnings of all the bulkhead to hull fillets.

Here is a view of some of the fillets in the aft section between bulkheads 1 and 2, where the aft bunk platforms will be. I have found that fillets are easier to do in stages such as this, making a smaller one to fill the gap and lock the parts together, then coming back later to sand the surface for good adhesion and making a larger fillet of the proper width and depth with a larger tool. The keel fillet will probably take at least two more applications, then it will be glassed, as will the lower bulkhead to hull joints. Getting to this stage today, of locking all the bulkheads in place, I was able to remove all the wire stitches holding the bulkheads as well as the keel stitches in the bow stems and stern posts. I'll remove the rest when the hull is upside down. I used 14-gauge steel utility wire for stitches, and found them easy to remove with the technique of shorting a 12-volt battery across the ends to heat them.

Here is a view into the midships section at bulkhead number 3, showing the diagonal stiffeners used to strengthen the hull in this area. The Spanish windlass rig I've got holding the hull panels tight to the bulkheads is no longer necessary now that the epoxy fillets have cured, and I'll probably remove all of them before I leave for work today. I plan to have a long weekend to work on the project over the Easter holiday, and will continue with the fillets and begin making patterns for the bunks. I will not have email access while I am away until then, and it has come to my attention that at least one reader has tried to post comments to this blog that have not come through. Your comments should come to my email inbox for approval (to eliminate spam), but not all of them reach me. If you have tried this and do not see your comment on the blog within a couple of days after posting it, please email me directly at