How do I waterproof the drive axle

I really think the packless coupling is the best way to go for a boat that stays in the water. However, when I restored our timber Folkboat a couple of years ago, I actually forgot to install one. By the time I'd built in a self-draining cockpit, it was a bit late to replace the original stuffing box. So, we connected a high-pressure line to the stuffing box grease reservoir and put a grease nipple on the end of the line in a more accessible spot, under a seat locker. I keep a small grease gun under there and each day after we've run the engine, I give the grease line one pump of grease. This grease seals the shaft against water dripping in while the boats moored. It works perfectly except when I forget to pump the grease! When this happens, there's usually a cup or two of water in the bilge after a week or two on the mooring. I do plan to cut a larger hatch into the floor of the cockpit to improve access to the stuffing box (and a couple of other things - you need to be an octopus to work on the nether regions of a Folkboat) however, and when I do that, I will install the packless bearing if the current arrangement is beginning to fail.

 

I know this is an old thread but I just now joined because I found it so helpful. In addition, I have found a clip on youtube which explains in great detail how mechanical (ceramic) seals work. It's tremendously helpful if you can ignore the stupid mime.

http://www.youtube.com/watch?v=__wqc1GfnZE

In case the link should expire, search youtube for:
"Mechanical Seals Basics from EagleBurgmann"