Re: Fiberglass buildup around rudder stuffing box
After looking at the cutaway profile in the Sailboatdata.com screen shot, I suspect that the leakage must be coming from one of two locations: around the shaft through the packing nut, because it can't be locked in place due to the lock nut being embedded in the "gunk"; or, as Faster hypothesizes, possibly up and through that mound of gunk itself, along the outside of the packing gland assembly, which may either be installed in a solid glass rudder-stock carrier tube through the hull lay-up or a conventional packing gland arrangement which relies upon a rubber tube secured to the outside of the rudder-stock carrier tube with double hose clamps and likewise secured to the packing gland assembly itself. In this case, I suspect the arrangement is the former--the packing gland assembly fitted into the end of the rudder-stock carrier tube. If the means of securing the packing gland assembly to the rudder-stock tube fails, it can/will leak and water will well up, along the sides of the packing gland assembly. From the discoloration on the packing gland nut due to corrosion, I am confident there is leakage at that point, although, whether it is the sole leak or just one of two, remains to be discovered. That it has been leaking, and sometimes more rapidly than others is also evidenced by the rust/corrosion in the lower half of the U-joint assembly which could be suspect itself. That assembly is likely held in place on the rudder stock with one or two set screws which, by now, may have given themselves up to rust, but it will definitely need be freed from the rudder-stock to replace the packing flax in the gland.
For what it's worth, I would start by simply freeing the locking nut and tightening and locking the packing gland nut in place. That may solve the problem and you're done. If not, get back to us and we'll give you some more advise regarding a lobotomy for the rudder stock carrier assembly. That may necessitate you cutting an access port in the sole of the cockpit or in the bulkhead on the aft end of the port quarter berth to get access to the hull under the cockpit. In either case, you've got some work cut out for you.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."