By S/V Lealea | March 10, 2016 at 12:14 PM EST | 3 comments
By The Skipper:
By now we have the straightforward process of staining and sealing the plywood pieces that will replace the old furniture in Lealea pretty well mastered. Unfortunately, our first attempt at a perfect finish with fiberglass cloth and resin turned out less than satisfactory.
We are not sure exactly what we did wrong, but the piece turned out something of a mess. No doubt, this is the fault of our application technique. I learned fiberglass basics while helping out Bob Twogood in Hawaii. Bob built fiberglass and composite kayaks, actually surf skis, in Kailua on the windward side of Oahu. From Bob, I learned to thoroughly wet out the cloth, then remove as
much resin as possible, leaving no air bubbles trapped in the cloth. In that application, a smooth, shiny pooled resin finish just means too much resin and weight. Bob used vacuum bagging to get
the maximum strength with the least resin and lowest possible weight.
We aren't vacuum bagging but, for the first layer of cloth at least, I figured the same principle should apply. We wetted out the cloth, spread the resin with a roller and removed the excess with a squeegee for a nice, even finish with the weave of the 6 ounce cloth clearly visible. For the second layer of cloth we used lighter, closer weave 4 ounce cloth and poured a generous amount of resin. Again, spreading with a roller and squeegee, this time tipping and smooth- ing the resin with a piece of roller sleeve.
We think we went wrong two ways.
First, it is possible we just didn't use enough resin on the second layer of cloth; or maybe we used too much in one coat.
Second, we may have had the work area too warm. Using System Three Silvertip resin with the fast-cure hardener was intended to allow us to work at temperatures down to 35f. What we did not anticipate and forgot to allow for, was that our work table was set up for the S1 penetrating epoxy which requires a higher temperature. The table was at 70f. The relative humidity was also at 70. The Silver Tip resin started to kick off while we were still working it. We felt the resin turning tacky while still rolling it on and got our hands out of it quickly but the resin does not completely hide the weave in places and the surface is somewhat lumpy.
As a structural bulkhead, it is plenty strong enough but heavier than it needs to be due to the excess resin. As a major visual element of the main cabin it would be a dismal failure which is why we picked this particular piece to practice on. Clearly, before we proceed with the main bulkhead we need to figure out what we did wrong.
Meanwhile there is removal of the galley, a lot of cleaning of the inside of the hull, fabricating and finishing of the interior furniture pieces and the ceiling. The anchor strips for the ceiling have to be
glassed to the hull and the interior of the hull must be painted before we can start putting it all back together.