Monday, April 30, 2007

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.

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