Cabin Sole and Tabbing

For a more thorough and professional explanation, see Lackey Sailing, LLC

For Friday, November 15th 2013, we just a couple goals in mind for the day, I started off my water washing and sanding the previous day's epoxy work: cabin sole knees and port v-berth / head bulkhead. 

With the amine blush removed, and the surfaces sanded, further epoxy work could be done (i.e. tabbing).

Building the cabin sole substrate would take considerable time, so we focused attention on this talk.  creating a cardboard template of first the starboard half of the cabin sole, and then the port half, Tim and I cut out the cabin sole substrate.  With significant adjustments in the fit and shaping of the cabin sole, we finally arrived a "really good."  In fact, the fit was amazingly good.   With a hand plane, I removed material in the "high" spots until the fit was level and resting on its marks.

Cabin sole level.

Employing the same process for templating the larger portion of the cabin sole (sorry, no pictures are available), we created a template for the aft section of the cabin sole substrate.  The process involved aligning a sheet of luan, or door skin on the boat's center line, and then hot-gluing tongue depressors onto the sheet of luan, forcing out to just touching the hull before the glue kicked.

We then slid this sheet of luan over to the starboard edge of the hull, made another center line reference mark, and repeated the hot-gluing of the tongue depressors to match the hull shape.  Down on the ground, we transferred the template to a section of 18mm meranti  and proceeded to cut of the cabin sole.

Test-fitting the aft portion of the cabin sole substrate revealed more hand plane work would required.  The amount of wood shavings in the bilge post-shaping began to look a lot like a wood boatyard.  In the end, the fit was very, very good - very little thickened epoxy would be required when the cabin sole substrate is permanently tabbed to the hull.

Next, we turned out attention to the cabin sole hatch. This rather large hatch would access to and removal of rather large water tanks:  47" in length, two of them.

Running a Makita jigsaw, I carefully traced layout lines for a 49" x 20" hatch.

Towards the end of the work day, Tim and I turned toward some tabbing work.  As Tim prepared the tabbing wet-out station, I donned full-face respirator, gloves, and my porter-cable 7335 with 40 grit PSA disks and heavily sanded the areas that would accept tabbing for the cabin sole knees.  After sanding, I vacuumed the salon interior to clean the area of fiberglass dust and wood shavings.  Last step prior to tabbing would be to solvent wash the surfaces.

Pictured below, the cabin sole knees tabbed to the hull.  The polyisocyanurate foam essentially acted as a form for the epoxy-impregnated fiberglass.  The foam could be cut with a utility knife, but the 1708 biaxial cloth would be as strong as an ox!

Lastly, with just an hour or so of work time remaining, Tim and I tabbed the starboard primary bulkhead.  I first gave the tabbing surfaces a good solvent wipe to clean and residues that may contaminate and compromise the epoxy bond.  Tim mixed epoxy thickened with cabosil, and I created fillets on the bulkhead hull joint.  A fillet is a radius transition between two surfaces, and allows for fiberglass to lay across to adjoining surfaces without creases forming in the cloth.  

Finally, the tabbing is laid on the hull and bulkhead.  The tabbing (1708 biax) is 6" wide.  To prevent creases, and subsequently air bubbles (the enemy of a good bond), the tabbing is divided into manageable lengths of, say, 16" or 24".  The idea being that as the hull angle changes, shorter tabbing sections will more easily absorb the hull angle change without crimping or creasing.  Two layers of 6" cloth are being installed on Westsail 32 hull #667.

Total Time: 8.5 Hrs.