After noticing that I had some drips from the rudder stuffing box last year, I decided to fix it before launch this spring. Removing the partition to access the area was easy; only one screw. I used a couple old foam seat cushions to lie on. It is tight quarters back there, and you have to place your head just forward of the rudder post and down low if you expect to see what you are doing. It would help if you are a circus acrobat.

The BIG picture

After reading the archives here on HOW, I decided I needed a good penetrating fluid to loosen the packing nut and locking nut. I picked a spray made by a local company, Castle. It is called Liquid Torch, and I sprayed it on liberally and let it set for about half an hour. I also tapped the nut with a small hammer to help it get in all the right places.

Penetrating Fluid

These are the tools I used, minus a good flashlight. The Channel-lock pliers will open to fit the nut-flats which are about 2-1/4 inches across. You might also try plumbing pliers from your local hardware store, or packing-nut pliers from your marine store. The marine pliers cost more of course. I also show a small chisel which I used on the prop-shaft stuffing box to loosen the locking nut, but didnt need it here. The most important tool is the pick to get out the old flax. I bought it at West Marine. It must be the type with a flexible shaft since there isnt much room to work. The small corkscrew will fit into the tight space in the nut. Turn clock-wise into the flax, and pull out the old stuff. If you need to buy this tool, make sure it is the small one. Price is about $12.

Tools used

My first purchase was Teflon coated flax, about $2 more than the wax type. I cut it and tried inserting into the space between the post and the nut with no success. I ended up buying the 3/16 inch wax type flax as shown.

3/16 inch Flax

I measured and cut the flax into three equal pieces. The flax is square, and I knew that it wouldnt quite fit into the space. This is where the hammer came in. I used it to flatten the lengths of flax enough to get it in. This worked well. Once I inserted a length into the nut, I pushed it up into the space at the top of the nut using some pliable plastic tweezers. This was difficult, and I was persistent by pushing and slightly rotating and moving the packing nut. I was just about to give up when it went in. With a sigh of relief, I inserted the next two lengths. Getting them pushed up was just as difficult. You can tell when it is right when you go to tighten the nut. You should be able to hand-tighten it downward about an inch.

I tried to stagger the three lengths so that there would be a good seal. It would help (in hindsight) to use a pen and mark where the ends meet on each ring, making it easier to stagger them.

Cut Flax

This is the beast I worked on. This photo was taken after I sprayed the penetrating fluid on and loosened the nuts. The bottom nut, or locking-nut, screws downward in a clock-wise rotation. The packing nut will then screw counter-clockwise until it comes off the threaded bushing. Clean the rudder post until it is nice and shiny. The top part of the nut is where 3-rings of the packing is stuffed. Use your tool to remove all of the old stuff. Once the new packing is inserted into the nut, tighten clockwise until hand-tight. I then gave it about a half turn more with the pliers and rotated the locking nut back up against the packing nut.

When launched, I will monitor the stuffing box assembly for any leaks, and tighten as necessary. Unlike the prop stuffing box, this should not leak. Of course, it isnt revolving like the prop shaft and doesnt need to be cooled.

I hope this job doesnt have to be done often. All phases were difficult. Prepare yourself!

I hope these instructions help those that need to replace the rudder stuffing box flax.

Packing nut assembly