Hull construction:

This weekend's project was to start on the fiberglass hull, and modify it for the Kerher jets. First step was to trim the outside edges of the hull with Dremel cut off wheel, down to the trim line. This was about a 1/4" strip that needed to come off all the way around the hull. The stern was the most difficult part to cut, as I had to make several right angle cuts without over cutting. A little patience and it came out great. Dumas also supplies a wooden keel, that needs to be attached to the out side of the hull, and I wasn't sure about the need for a keel with jet propulsion, but several replies from a post revealed that a keel would provide directional stability. So I just went ahead with it. (I can always rip it off later, if it doesn’t work out) The instructions say to cut three slots into the bottom of the hull, and set the keel through, then epoxy in with a thickened mixture. I also ran a bead down each side of the keel where is meets the hull, so it blends together nicely. With the cut off wheel, I also hacked off the transom in order to make a recess box for the Kerher jets. My plan is to make a new transom out of 1/4" ply, and fiberglass it in about 4” forward from the stern, then add sides and a top to enclose the jet drives under the hull. I purchased some 1/4" ply, and used a paper template (trial and fit) to match the inside contour of the hull, which was then dry fitted for marking. As you can see from the photos, the jets were mocked up in the hull, and positioned and marked for alignment. Once I was satisfied with the marks, I glassed the transom to the hull. While the transom was curing, I went ahead and applied filler to the inside sides of the hull. Dumas put some strips of fine cloth here, so to make the finishing more easy. This part of the hull will become the inside of the companionway and is exposed, so it needs to be smooth and finished. Once the transom had cured, I cut out the sides of the stern box from scrap plywood, and epoxied them in place. The Kerher drives seemed to extend a bit to far up the transom than I would like, so I am going to modify the hull intakes, and mount the units flush with the bottom, this should drop the output holes about 1/8”. Next week I will finish cleaning up the stern and cutting the intake holes. So far, this has been the most difficult part of the construction.

Until then…
“Time” to go boating.
-Chris