rudder box stuffing replacement

[Jumbyway]

I'm getting ready to replace the stuffing on our Bayfield 36 rudder and I know that there is a trick to cutting the pieces for an exact fit, but my old brain just isn't recalling it. Any help?

[Ziggy]

Take out the old pieces and cut the new ones to the same length?

[never monday]

wrap the new packing around an exposed piece of shaft. Mark where one wrap ends and cut with a shard razor blade.

[GordMay]

Wrap the stuffing rope around the exposed prop’ shaft (about 5 times) and then cut across the windings on the diagonal, producing 4 individual* rings with scarfed ends. Use a very sharp knife, or razor blade.

* You don’t want a continuous wrap, but a series of (usually 4) rings, with the diagonally scarfed cut ends offset (staggered) about 90 degrees from each other.

Since Circumference = 3.142 x diameter:
4 rings will total about 13 times the diameter (4 x 3.142 = 12.568)

Each ring should be installed separately, and enter the stuffing box freely. Rotate the shaft after each ring is fitted and caulked home, using a wooden or hard plastic rod or wedge*. Most packing compresses, and unless this compression is taken up on each ring as it is fitted, the stuffing box will not be properly packed. Care must be taken to ensure that the joint of each ring is staggered with the previous one by 90 degrees, moving them progressively through the full 360 degrees.

* Don’t use a screwdriver to install new packings - you may score the shaft, or damage the flax rope.