Brackets and Cleats

Over the past couple of days, I have been adding coats of epoxy to the hull exterior to fill the weave of the glass cloth. Between the last two, I sanded the surface with 100-grit paper to knock the peaks off the texture that was printing through the epoxy. With a nice, smooth surface produced, I then flipped the hull. The next step was to install some fittings, including seat cleats and brackets for the foot brace rails. The forward set of brackets are normally through-bolted, with a bolt head visible on the hull exterior. Instead, I used some special fittings with a bolt and perforated plate which were glassed onto the hull interior. The position for the forward foot brace rails was measured and marked. The substitute bolts require the plastic rails be drilled out slightly to enlarge the existing mounting holes. These bolt brackets were then glassed on the surface of the hull with a combination of silica thickened epoxy and unthickened epoxy to wet the glass tape that had been cut in 3" x 3" squares with a hole cut in the center. Once the glass was wetted, I taped the bolt to hold it in place. The instructions call for rolling the hull on its side and allowing gravity to hold the mount in place until the epoxy cures. This would have been easier and neater.

The aft pair of foot braces will be screwed into riser blocks so as to clear the hanging knee in that location. These blocks were simply epoxied into position and held in place with tape while the epoxy cured.

Finally, simple 3/4" x 3/4" pieces of lumber were epoxied into place on the hull floor to serve as seat cleats, or guide rails for the seat assemblies. Care must be taken to use the correct pieces of wood: for each seat there are four pieces of lumber- three are longer than the fourth. Two of the long pieces are used as the seat guides, while the third is used as a structural part of the lower seat. The fourth, shorter piece is used as a structural part of the seat back. The guides were measured and aligned, then epoxied into place with silica thickened epoxy and weighted until cured. Total hours 28.25.

Fill the weave

Another coat of epoxy was rolled on the hull exterior in order to "fill the weave". This is merely the procedure to build up a layer of epoxy just sufficient to cover the texture of the fiberglass cloth and produce a smooth surface for later varnish or paint. The coat last night was very thin; I can see already another will be required.

Also, I have worked out a rough timeline to finish the Mill Creek 16.5 construction. The goal is to have major construction finished by the end of this month. That will allow about two weeks for finishing, varnishing and painting. So by the middle of June, we should be ready for water. The ultimate goal is to paddle around the harbor in Mystic CT during The WoodenBoat Show 2008. Total hours 24.50.

Hull Glass

After some prep work, including filling stitch holes and chine gaps with thickened epoxy, and a final overall sanding of the hull, the fiberglass could now be applied. A large bundle of 6 oz fiberglass cloth is supplied for this purpose. It is unfolded and draped over the hull, and the excess trimmed off to where only a small overhang remains beyond the edge of the sheerclamp. The loose weave of the cloth allows it to be arranged without wrinkles fairly easily. Then, in a technique detailed here, batches of unthickened epoxy were mixed and poured onto the flat surface of the hull. Using a rubber spatula, the epoxy is gently spread so as to wet down the cloth. The idea is to get the cloth just wet enough that it turns from white to clear, but so that some of the cloth texture remains after the epoxy is cured. This allows the cloth to adhere to the wood of the hull, providing strength, durability, and waterproof-ness. Adding excess epoxy also adds weight, and runs the risk of "floating" the cloth out of close contact with the wood, reducing strength. It is a slow and painstaking task, but after a couple of hours, the hull was glass coated. Then, after a couple hours, when the epoxy was semi-cured, I trimmed the excess cloth from the bow, stern, and sheerline. Additional cloth tape will be applied to the bow and stern, and additional thin layers of epoxy will fill the weave of the cloth, leaving a smooth surface. Total hours 23.45.

Bow fillet and tape

After a brief hiatus for a trip out of town, building of the Mill Creek 16.5 resumed. Today's job was the fillet and taping of the bow compartment. With a now familiar procedure, the joints were filleted with peanut butter thickened epoxy, followed by a fiberglass tape overlay. This was then wetted down with the layer of unthickened epoxy. Doing a neat, smooth job was difficult, especially in the very tip of the bow, for one such as me with less than dainty hands. But tight quarters notwithstanding, the joints were sealed and glued, thus completing the preliminary gluing of the hull. Total hours 15.25.

Cockpit tape, part II

Today I completed filleting and taping the joints on the port side of the cockpit area. Even after the practice of the starboard side, the identical job tonight went no faster. It is tedious work to get the epoxy fillets in place with reasonable neatness, overlay the tape, and wet it down with epoxy and then smooth wrinkles and remove air bubbles from under the tape. However, the job is done. While others may be able to produce neater fillets, mine should look decent under the painted finish I have in mind for the interior of this copy of the Mill Creek 16.5. Total hours: 14.25.

Cockpit tape, part I

I tackled the filleting and taping of the cockpit today. Or tried to- things went slower than I had expected, so I ended up just doing the starboard side of the boat. As previously, a fillet of thickened peanut butter epoxy was laid down on the joint between each panel. I then overlayed the fillet with glass tape I had previously cut to length. Each side required three lengths of tape to fit between the hanging knees on the upper joint between the sheer panel and the bilge panel. I cut the lower tape in one piece, and merely cut a notch to accommodate the lower edges of the hanging knees. After getting the tape in place, I wetted it down with unthickened epoxy. This took a surprisingly long time, as I worked to get all the air bubbles and wrinkles out of the tape. Total hours: 13.00.

Fillet and Tape

The construction of Dragonfly has now progressed to the "glue" portion of "stitch and glue" boatbuilding. First, a final check of the hull's alignment showed that everything was in place. Using a technique called "winding", the hull was checked for twist by placing two straight pieces of wood across the sheerclamps, and then sighting down the centerline. With the two pieces of wood superimposed, the hull showed no twist. The point of the bow and stern were plumb, and all appeared in readiness to permanently joint the parts of the hull with epoxy and fiberglass.

The first step is to apply a fillet of wood flour thickened epoxy to the joints which will provide a smooth radius for the fiberglass tape to come. The epoxy is mixed t0 peanut butter consistency, which makes it reasonably easy to apply with a wood tongue depressor, then smooth with a rubber spatula cut to the appropriate radius. The only difficulties I ran into was the fillet on the joint between the sheer panel and the bilge panel. Near the stern, this joint had almost no angle (or a 180-degree angle), which made a clean fillet more difficult.

With the fillets in place, and before they cured, I overlayed them with strips of 3" wide fiberglass tape. The tape was then wetted down with unthickened epoxy to form an integral, strong joint. At an ambient temperature of 85 degrees, the slow-cure epoxy is setting up fairly quickly, so the boat is done in sections; today I did the stern behind the aft bulkhead. Tomorrow- the bow and center compartments. Total hours: 11.75.