SV Pilgrim - 1979 Morgan 382 - Homeport: Beaufort, NC

Tuesday, June 24, 2014

Fairing the Hull Repairs

The structural portion of hull repairs concluded with the application of a few additional layers of 1708 cloth.  The initial fairing (smoothing out and making the repaired areas match the arc of the hull) consisted of a  layer of cabosil thickened epoxy over obvious depressions and rough areas.

Hull repairs under the head after two rounds of fairing with cabosil.
In the interest of not penning a tome and boring you all with the repetitive nature of this process I will abbreviate by simply stating that, “we added another layer…” or “the next round of fairing…”  Note that each application of fairing includes…  12+ hours of curing, washing the previous application with soap and water; rinse; sanding, sanding, sanding; another wash & rinse;  wipe down with acetone;  apply the next round of fairing; and start again with 12+ hours of curing…
Hull repairs under the port side cockpit after two rounds of fairing with cabosil
After two rounds of fairing with an epoxy / cabosil mixture, the hull appeared relatively smooth, but running a hand across the large repaired areas revealed undulations in the surface.  The solution…“stripe the hull.”

Anne & I used epoxy thickened with Q-cell filler and a notched trowel to apply a layer of peaks and valleys across the two largest repairs, portside under the head and portside under the cockpit.
Striping the hull with Q-cell thickener
The Q-cell filler consists of microspheres, think tiny hollow egg shells.  The tiny hollow spheres add little weight and no structural benefit, but allow for thick applications that sand down relatively easy. 
Portside under cockpit repair with layer of stripes applied.

Well “easy sanding” may be overstating it a bit when using a 30” long board with 40 grit sand paper to remove the excess material.  The flexible long board mirrors the shape of the hull while sanding down the stripes.
Sanding with a long board is HARD Work, but yields good results

After a few exhausting hours of long boarding, the split over two days, the stripes now revealed the depressions in the hull repairs…
Sanding the striped area with a long board eliminates the filler from the high spots and leaves an easy to fill area in the low spots.
while the high spots are sanded bare…
Portside under cockpit repair ready for the next round of q-cell filler.

We then used a smooth, 6” trowel, to apply another round of q-cell thickened epoxy over the stripes.
Portside under cockpit repair with one coat of q-cells appiled atop the remaining stripes.
We also applied the mixture to many of the smaller repairs that required a bit more fairing to blend in with the surrounding hull.

Starboard side under cockpit repairs with q-cell fairing applied 

Fairing required applying to rounds of the epoxy / q-cell mixture, but the end result is fantastic.  Our repaired areas are now smoother than the untouched areas of the hull.
Portside under cockpit repairs complete and ready for barrier coat.
That is not to say I am willing to put the time and energy into fairing the entire hull.  We do want to actually get Pilgrim on the water this year.
Portside under head repairs complete and ready for barrier coat
Our plan now is to apply a couple coats of barrier coat over the repairs.  The barrier coat will prevent UV damage to the bare fiberglass while we wait for cooler weather the finish removing the bottom paint.
Looking aft down the midline of the hull after washing down dust from sanding bottom paint.
In the fall we plan to remove the remaining bottom paint, repair any additional blisters, barrier coat the hull, and apply new anti-fouling paint.

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