I've been messing about with my eel rigs these last few days. As ever when it comes to rigs my aim is to simplify them. For the last few years I've been using quick change swivels at the end of the mainline, with a rig sleeve on the trace covering the open eye of the swivel. Although the swivels are strong enough they are a bit long, and rig sleeves never seem as tangle proof as they should be. Is a swivel really necessary? I'm not sure that any other than ball bearing swivels actually snivel very much in use. As I wanted to retain the quick change facility (eels manage to trash traces!) I tried out a Q Link (other brands are available...). I swapped my previous rig sleeve for a stiffish tail rubber and covered the rest of the link with a buffer bead.
The lead link is made from 20lb Mason Hard Type Mono, which I've found is far more tangle free than standard mono. A large eye swivel has taken the place of a leger ring as braid grooves plastic and I've used these swivels on my barbel rigs for years. The tail rubber over this swivel is optional. Even without it the rig has proved tangle resistant. A small polyball or cork ball could also be used to cover the knot if weed is present.
The other end of the link has a paper clip for the lead as a weak link. One word of caution with paper clips. They can snag in micro-mesh landing nets. I'd never had this problem with my wide mesh barbel net, but my eel net has caused me problems. I'm concerned that sleeving the paper clip might prevent it opening out on a snag, so for the time being I'm putting up with the occasional net tangle.
Hard mono is more difficult to knot than ordinary nylon or copolymer, simply because it is so stiff. When using it as a hooklink or on a John Sidley rig (which I'm still unsure about the need for) I take the trouble to carefully tie a Uni Knot for strength, but for lead links I use a knot that I have recently stumbled upon on the web. The Davy Knot is untidy, and possibly not very strong, but it is simple and quick to tie. Ideal for weak links.
Back when my friends and I started using big jerkbaits the braided lines in use today weren't available, so we used mono of 25lb or more. Because of the repeated force of casting heavy lures the trace knot needed to be retied a few times each day to prevent unexpected crack-offs. I carried a pair of clippers for trimming the knots in this line as they made a better job of it than scissors. Scissors struggle a bit on hard mono too, and I worry that it could blunt them. You can buy line clippers, but they can cost a tenner. Nail clippers from the chemist's at under two quid do just as good a job. The ones I have also incorporate a file - so I can give myself a manicure between runs!