Need help with packing gland...

[glcalahan]

I am restoring a '72 Pearson 33 and I had to replace the prop and shaft. The shaft is 7/8" and the new packing gland came with 5/16" flax. I cut 2 wraps and installed the first and ran nut the drive to the bottom but when I added the 2nd wrap found only 3-4 threads left. Now I am wondering since the flax is square 5/16", question: is that also the distance from shaft to inside the packing gland?? If I used 1/4" flax and used 2 wraps (1/2" total), would I assume that the flax will spread out as it is tightened?

Any help or suggestions would be appreciated. BTW...I am using 5/16" GTX with Teflon.

Thanks!