feather weld is quite good but if you don't have any lying around then try using ordinary varnish by putting it on fore finger and thumb very lightly and then slip the J.C through your fingers with steady pressure and repeat if needed but i find only once is all thats needed if done correctly the first time .
their is a link to a post that shows what to do by step by step i will see if i can find it for you.
here are some good links.
Jungle Cock, Selecting Using and Repairing - Global FlyFisher
Ronn Lucas Sr
these should give you all you need to know and more.