Last summer, whilst sailing with some friends in Casco Bay, and yours truly dutifully watching the chartplotter, we suddenly felt a “badumpbumpbump”. I looked over the stern and there was a pile of weeds, obviously growing off a pile of rocks in the middle of nowhere. I looked at the chart, and saw nothing. Well then, it snuck out from behind the boat symbol showing where we were. The boat icon was so large that it obscured a small indicator saying “rock”. That icon is now small scale, rather than large. And …. the rock is marked with a big red “X” on the chartplotter screen.
When fall came around and 5Q was hauled out for the winter (remember, that was not supposed to be the case I was supposed to head South in September 2014) I looked at the starboard keel, expecting to see a chunk missing. Much to my relief there was no sign of a grounding, but the starboard rudder had a compression area at the bottom that was the result of kissing the rock. That made it simple – drop the rudder, take it to the shop and patch it. Much better than lying on my back effecting an in field repair.
Upon reading about Leopard rudders, I learned there were some defect issues that were common to experience, plus I found out the rudders had balsa core in them. Really? Balsa core in a rudder? So the decision was made to tear it apart and rebuild it the proper way.
First things first. I own several CNC machines and I could have created a 3D CAD file and cut a direct mold, but I was too lazy for that. Instead, I fixed the aforementioned boo-boo, faired and sanded the rudder, gave it an overcoat of paint and sanded, buffed and polished the mold, to turn it into a master pattern, or plug as we call it in the composites industry.
After several coats of sealer and release agent, a 30 mil thick tooling gelcoat was brushed on. The fiberglass was laid down in a matrix of vinyl ester resin, a tough resin that will handle the heat of curing fiberglass/resin of the rudder. Then a wooden structure was added to help it stay in shape, flipped it over and a mold made of the other side, following the same process.
Now the hard part. I tackled taking the rudder apart with grinders, air saws, chisels and hammers. It consumed over an hour of nasty, hard work. Yes, the balsa inside was wet and mushy, water having migrated down the stainless steel rudder stock.
I won’t go on about how poorly I think this rudder was constructed in many ways. Suffice it to say, it won’t be the same when I rebuild it.
I had a local fab shop weld three flat bars to the rudder stock, as should have been done in the first place.
Next was the layup of the skins, or outer layers of fiberglass. After spraying 30 mils of white gelcoat, five layers of structural fiberglass fabric in various fiber orientation were added to the mold. At the bottom of the rudder cavity I added, five inches up from the bottom, a resin filled with chopped fiberglass strands. The thought is that when I next go aground (and I will) the lower end, being only fiberglass and resin, will be easier to repair.
Tomorrow – adding expanding epoxy foam to the interior. Sounds exciting, no?
More to come … this is a test using Microsoft Live Writer