I am new to the UBass and even newer to this board, but I have been involved with musical instruments since 1958.
It is with the outmost interest I read the UBass megathreads. Starting from the beginning of the first part, but that would take me long time to get to the newest information, so I started reading part 4 backwards.
I noted the problems with slipping of the Pahoehoe strings, and when tuning up last night I had such experience myself. As soon as the pitch stability gets dubious I look for double-layered windings on the tuning posts. I had corrected that successfully with the E, A and D strings. And thought I had succeeded with the G string also. At any rate I trimmed the surplus from all 4 strings, when the G string slipped. I havent come to buy spare strings like with my other plucked string instruments, so I had to find a solution as the string wasnt long enough to make a knotted loop like suggested by Kala.
Fortunately I have learned about knots many decades ago even if I dont know their English names. A single knot like this one would slip:
https://www.dropbox.com/s/l80agh6be5cvjom/2012-08-12%2003.23.45.jpg
So I made the first loop of a surgical knot, that is about taking the end through the loop once more:
https://www.dropbox.com/s/eiur39lbfwgqeey/2012-08-12%2003.24.11.jpg
That knot will not slip when tightened, and it will not slip through the slot of the tuning post.
I am going to experiment with Thundergut strings also, even if I find Aquila strings for ukuleles and guitar a bit stiff on my fingers. There I prefer Worth. But from Worths own description they are not radically different from the Pahoehoes. And their colour doesnt invite me either.
It has been mentioned that the Thunderguts tend to slip when knotted below the bridge. I hope the extra winding on the knot will solve that problem.
I used an electrical cord for the illustrations. Against my expectations I couldnt make the photos show up directly from Dropbox.
Klaus Smedegaard Bjerre in Denmark