UKC

Quick question:

How much tail should be left behind on a double fishermans knot? I had originally wanted to leave about 2cm and tape that to the other cord to keep it tidy, but now I'm wondering if that is going to be safe.

I am making prusik loops

Cheers in advance

In reply to phicklephancyphree: I go with about 10x rope diameter, so about 5cm for prusiks. I personally tie prusiks with offset overhands (same knot as the euro death knot used for abseiling) as it makes untying them easier if I need some extra tat.

Kane

In reply to phicklephancyphree: a double fishermans will stay nice and tight, you wont need to check the knot in an emergency. my 2p worth.

In reply to phicklephancyphree:

A double fishermans won't slip, and in any case the load on a prussik loop is pretty low. 2cm sounds fine to me (its about what I have used for years)but I wouldn't bother with the tape in case you want to untie the cord for some other use (maybe a thread).

In reply to phicklephancyphree: The best official advice I am aware of is 8x the diameter of the cord which is taken from a technical publication produced by the respected Combined Services Caving Association. See http://www.cs-caving-association.com/CSCA%20Publications/Knots%20A5.pdf

However FWIW the tails on my own prussik cords are a bit over 30mm in 5mm cord (i.e 6x the diameter).