Dueling Dhows: Fairing the White Dhow / Blue Dhow Hull Repairs / Fabricating a Daggerboard Trunk

April 14, 2018

I began the day by water-washing the amine blush from the now cured fairing compound and fiberglass work done on the white Dhow. With a scouring pad and water I gave each of the repair areas a good scrubbing to remove the film of wax that results from the cured epoxy resin.

With the vacuum and RO sander set up with 80-grit pads, I got straight to work fairing out the repairs.

I switched to hand-sanding to bring the tight radius edges to fair with the surrounding surfaces.

This was a good first application for the white Dhow, but more to come on the fairing side of things.

With the white Dhow's fill work sanded down to roughly fair, I moved over to the blue Dhow to complete the prep work to begin its first filler application. There wasn't much in the way of sanding and grinding required, but I did ream out some old fastener holes as well as placing tape on the inboard surface of the hull to provide backing for the thickened epoxy filler to be applied.

I thoroughly wiped both hulls down with a solvent - a surface degreaser for the blue Dhow and acetone for the white Dhow. Starting with the white Dhow, I mixed a small batch of epoxy and thickened it with 407 low-density and 406 colloidal silica. Using a squeegee, I skim-coated the previously filled and now sanded repair areas. The second coat will fill any remaining voids that the first application misses, it will also help bring some of the repair areas to fair with the balance of the hull.

I moved around the white Dhow fairly quickly, applying the required amount of fairing compound.

With a good amount of the fairing compound leftover, I hit a number of the bottom "scars" on the blue Dhow so as to not waste the pricey West System materials.

I then turned my attention to the major hull repair work for the blue Dhow - well "major" is a purely subjective term here, meaning that the repair required laminating a bit of fiberglass to further strengthen the hull. I set up a work station to the aft of the Dhows, and then got to work creating pattern for the fiberglass cloth required.

As i had done on the white Dhow, I used sheets of 5mil plastic to transfer the area I had ground out on the hull to the pattern. I started on the port aft quarter and then worked forward, labeling both the patterns and the location on the hull where the fiberglass cloth would be applied. I also used a orienting mark on the pattern.

Taking the pattern back to the bench, I then transferred the pattern to the fiberglass cloth with a marker and cut it out. I repeated this exercise for all of the cloth to be applied on the port side. With all pattern applied and cut out of the fiberglass, I then mixed a batch of neat epoxy and applied a thin coat to the repair areas. With all repair areas wet out, I applied the fiberglass and continued to wet the cloth to ensure there were no bubbles or dry spots.

I worked the port side fairly quickly, paying attention to the heat in the cup since our Florida temperatures are beginning to creep in the direction of inferno!

I repeated this exercise for the starboard side of the hull, completing the application of fiberglass to the repair areas requiring it.

With the fiberglass patches on the port side of the hull now tacking up, I mixed a small batch of thickened epoxy and squeegeed this over the cloth to fill the weave. I typically fill the weave after allowing applied fiberglass to cure - require a lot more work, frankly. Filling the weave in the same open working time reduces work immensely: eliminating the water-washing of the amine blush, directly sanding the cloth resulting in a cloud of prickly debris, and generally inefficiencies.

Both hulls are closer to primer coats!

With bringing the hulls to a point where I could do no additional work, I retreated to the shop for a beer, a cigar, and fabrication of a daggerboard trunk. The blue Dhow is a sailing version of the 7' 11" Midget, and so therefore has all of the accoutrements of the sailing version. The white Dhow is not a sailing version, so I am fabricating the components required (the ones that I do not already have): daggerboard (db) trunk, db to seat support, and mast step. A friend of mine had given me, years ago, all of the sailing gear for the sailing version (less the hull and the components attached to the hull), so that would be the mast, the yard, the boom, the rudder, the daggerboard, as well as the forward seat with the mast hole to allow it to seat onto the mast step.

I decided to fabricate a number of parts to replace existing (damaged or dry-rotted) parts across both Dhows, but for tonight it would be at least one of the daggerboard trunks. I took the dimensions and angles off of the db trunk from he blue Dhow, and began to cut new material on the table saw. I have a number of meranti scraps taking up precious space within the shop, and because the meranti (type of mahogany) is a marine grade material, in fact I used this material for the Westsail 32 bulkheads, it would now be perfect for the Dhows. I will be coating the wood with epoxy and then painting them, so the surfaces will be protected from water and UV.

I removed the primary boards from the meranti scraps, and then used a 5/8" piece of teak to open up the db trunk to allow the daggerboard itself to slide into position. Clamping the assembly firmly in place, I pre-drilled and then drove screws into the four corners.