10.17.2009

forward bulkhead

In order to install the cabin top and foredeck, I needed to finish taping the forward bulkhead in place.  Unlike the mast, cabin and aft bulkheads that receive 10 layers of uni on either side, the inner bridge deck portion under the forward bulkhead receives two 8 inch wide lengths of uni directional glass with their ends lapping out onto the forward bulkhead. In this photo, you can also see the "optional" foam strip where the mast support web will be installed.  I chose to use these foam strips along all critical hull to bulkhead joints because they provide a wider base that helps distribute loads more uniformly.

10.13.2009

rounding off the corners


The inner corners of the cockpit coaming are formed by shaping foam wedges and bonding them in place. This 8 inch radius corner will be viewed as part of the aft starboard cabin ceiling.

In this instance, I've used polyurethane glue, a few small sheet rock screws and a bit of packing tape to hold the wedges in position while the glue cures. The corners will then be sanded smooth prior to glassing the decks.

stern view


The bridge deck "transom" is now in place. This panel was vac bagged on one side with 24 oz. triaxial glass leaving the exterior foam exposed so that it can be shaped and glassed later when doing the decks. This will allow the exterior aft bridge deck portion to be glassed in one continuous lamination.

bonding the bridgedeck "transom"


Here's an inside look at the bond confirming a good squeeze out of the bonding mixture. Note the temporary screws used to pull the pre molded flanges into the back side of the panel. Obviously if I had skinny 8 ft long double jointed arms I could have taped this panel in place without resorting to all this complexity.

pre molded flanges


Here are the resulting molded flanges to which
i will bond the bridge deck "transom" panel.  Next step will be to scribe the panel, cut and fit it,  swipe a mixture of epoxy thickened with cabosil all over the flanges then bond the piece in place.

10.12.2009

closing in the "I" beam


Here's a close up of the aft bulkhead with the two temporary foam pieces that will be used to create internal flanges.  In this case, I've used packing tape over some scrap foam so that I can then form the flanges by laying glass "tape"on the back side of this "packing tape" covered foam.

The Aft Bulkhead


The aft bulkhead get's built up as a major structural member of this ship. It is essentially an "I" beam with the shear web being the bulkhead itself and the flanges being made up of the deck and lower bridge deck sections;  both of which are sheathed with ten layers of uni directional glass. Once this "I" beam is in place, it then gets boxed in from the front by the aft portion of the cockpit and then the aft section of the boat. Since it is not possible to tape the seams of these sections from the inside, tape flanges are being formed to allow these pieces to be bonded onto the lips of flanges.  In the photograph, you can see both top and bottom horizontal foam pieces that are covered with clear packing tape as a release. I'll tape these removable flange pieces in place then once cured, I'll remove the temporary foam pieces to reveal the glass flanges.  Then, I'll rough sand the flanges, trim the bridge deck "transom" piece and bond it in place.....then I'll perform the same dance when installing the aft cockpit piece.