I had a couple of bust-offs the other day. One was on braid, the other on nylon. I think I had leaned a little heavy on the drag with the nylon, and it was only eight kilo up against a mackerel doing the million-mile-an-hour

thing, so I deserved it. I swapped spools to the braid, YGK PE3 Power Hunter rated at about 35lb, and did the same again on the next cast. I didn’t deserve that, I thought.

I’ve been using that particular braid a fair bit for the last year, and I think that might have been the first time I had broken it without getting wrapped around a rock somewhere. This time, the fish – another mackerel – struck within a moment of the lure’s splashdown, so it was probably 70 or 80 metres away. I swept the rod up, the fish shot down with a shark in hot pursuit, and the line cracked off with absolute finality. Poo. It was all pretty visible from 12m up on the rocks.

Of course, being in the tackle trade, I’m used to people breaking off for no apparent reason. They come in and tell us about it all the time – usually with a spool of braid in their hand, a disgruntled look on the face and a mission for the day, which involves not leaving with the same spool of braid.

About one time in 10 or 20, they’re justified. The 50lb braid breaks at 20lb, for whatever reason. Have a new spool. But really, just about every time, the 50lb line breaks at near enough to 50lb, and the problem lies with the angler’s knots, or guides, or drag, or technique (mine lay with a combination of knots, drag and technique, for the record).

Neil Griffiths, the owner of Jones’ Tackle (www.jonestackle.com.au) in Brisbane, also encounters the same thing, and he’s done some interesting research. He was particularly looking into exactly what was happening when people broke off on the strike with heavy popper-chucking gear, like what we use for giant trevally at Exmouth and points north. Some of it applies directly to all fishing with braid, even down to the two-kilo stuff with bream.

The first thing Griffiths did was borrow a hideously expensive digital force gauge that, unlike a line-testing machine, was capable of recording instantaneous maximum loads over very long lengths of line. It’s a bit like a very sophisticated set of digital weighing scales, but costs far more than any tackle store could justify investing in. The line he used was Western Filament’s Tuf-Line XP in 80lb, which is popular worldwide and known as one of the good braids. It’s braided in the USA from Spectra fibres, which are made by Honeywell in the USA, and it’s typical of a top quality braided gel-spun polyethylene line. Western Filament know what they’re doing.

The XP tested in a straight pull, no knots, at 44kg (80lb=37kg, near enough). Griffiths rounded the results to the nearest half-kilo in all of these, incidentally. So to start with, the line was actually under-rated for breaking strain; and unless they’re in pursuit of a world record (refer last issue’s column), nobody should have a problem with that.

I’ll fill in a bit of detail before getting into the rest of the tests. Most knots in any line reduce the breaking strain, and anglers fishing to the max minimise this problem (typically) by tying a Bimini Twist in the line, which can be a 100 per cent knot (no reduction in line strength) when tied properly. A Bimini Twist leaves you with a loop in the end of the line, so you now have a double line to tie more knots with, and if you’re reasonably thoughtful about what knots you use with the double line, you have plenty of leeway about what you can tie without getting down to something that’s weaker than the single strand. Follow that?

One of the popular knots amongst the GT popper-chucking brigade, at least in some areas of the world, is called a Midknot. It was apparently originated by a Japanese angler, Hiroshi Kobayashi, who is fond of fishing Tokyo Bay for seabass in the middle of the night. His nickname is ‘Midnight’, which although an English word, is commonly used in Japan.

Just getting back to the Bimini Twist, it’s a 100 per cent strength knot in nylon if you use more than 20 turns. In braid, I religiously use – or used to use – between 50 and 55 turns. Griffiths’ tests had Biminis tied in the braid with 70 turns, and also with 30 turns, if only to show that all Biminis are not created equal. Read on.

The first test was a gradual pull, to achieve the highest breaking strain, over each of three knots, with three tests on each. The results showed a 70-turn Bimini Twist achieved 41kg to 43.5kg, pretty good and good enough, but not 100 per cent. A 30-turn Bimini in the same braid tested out at an awful 21.5kg to 30kg, so there’s a clear enough message right there. The Midknot was almost as unimpressive, at 23kg to 28kg.

Test two was a moderate shock, like a small fish connecting. There was little elasticity here to absorb the shock, something to keep in mind when you see how weak 44kg braid has suddenly become: 70-turn Bimini 31kg to 35kg, 30-turn Bimini 15kg to 18.5kg, and Midknot 21kg to 25kg. Test three was a heavy shock, as best Griffiths could do to imitate a strike from a strong fish. Still with no elasticity for shock absorption, the 70-turn Bimini expired at around 15kg, the Midknot was good for only 9.5kg to 11kg, and the 30-turn Bimini – well, don’t bother.

Test four was the scary one for the operators, the sharpest shock possible with no leader. Griffiths didn’t want to do it more than once on each knot, but it was already pretty obvious where the results would be heading. Both the 70-turn Bimini and the Midknot recorded 8.5kg breaking strain. Think about that – that’s 80lb braid, with a good knot in it, breaking at less than what could be reasonably achieved with a steady pull on 20lb nylon and a good knot.

In GT popper-chucking, a nylon or fluorocarbon leader is always used. Some anglers like to keep it very short, to keep the connections to the braid up in the guides or even outside the rod tip when casting, to eliminate guide wraps. Others use longer lengths that put a few turns on to the reel spool, for more shock absorption and more abrasion resistance. After reading this, you might favour the latter path for your own fishing with braid.

So Griffiths continued the testing, to show the difference a stretchy leader can make. The loop created by tying a Bimini Twist favours using a twisted leader. Griffiths refers to it as a “Super Twisty”, and makes his 3.7m GT leaders out of nylon with a breaking strain between 80lb and 150lb. On the tests he conducted here, a 3.7m leader stretched 60cm under a 30kg load; not a huge amount at lower loads, but enough to make a difference.

The Midknot is intended to provide a slim connection into a single strand of heavy nylon leader, which doesn’t stretch much in comparison to the twisted leader. It wasn’t re-tested, as even a long length of the stretchiest of thick nylons would not stretch much at the low strains the knot was breaking at. You could expect to see a very minor improvement.

So on a 70-turn Bimini Twist, adding a 3.7m twisted leader upped the breaking strain in test two from 31-35kg to 40kg; test three improved from 15kg to 25kg; and test four went from a miserable 8.5kg up to a catch-saving 16kg of breaking strain. In all instances, it was the Bimini Twist or the Midknot itself that broke, not the main line or the leader.

There are an endless number of ‘what-ifs’ that can be raised here. One of the most obvious things to learn here is that when fishing braid, there are benefits in using a heavier breaking strain than you might think you need, and starting out with a lighter drag. There’s lots of talk about ‘starting inertia’ in reel drags, and Griffiths’ tests above show that even 5kg of running drag on a 40kg line (half what you might get away with on nylon) can be too much, in some instances, for braid once you whack in some inertia.

One of the knots I know a lot of people use now to join braid to a mono leader is a roll knot, or call it what you will, a worm knot, f-k knot and so on. It’s so easy to tie it just has to be desirable. I was even becoming that confident with it, I was recommending it to somebody on the night of May 6th. I remember it well, because on May 7th I had one come undone for the first time, on PE8 joined to 130lb leader and one of those GTs you’d love to have seen. I’ll go quiet on that one again for a while. Maybe it doesn’t agree with heavy lines. Thanks to barbless hooks and a floating lure, I got to have a good look at exactly what had happened there, and the simple truth was the knot pulled through. I’ll keep on using it on lighter stuff, and throw a few more turns into the Bimini that I tie in the braid first.

My own research on the Midknot turned up that it won both first and second place in the 2001 Japan Game Fishing Association knot contest (don’t ask me what is required to do that). Their tests showed it to average 96 per cent of the braid’s breaking strain. Griffiths’ tests gave it less than 60 per cent on the kindest of pulls, which indicates to me that it can be a good knot, but it’s hard to tie reliably, even by a very experienced angler. Even Biminis can be tied badly, but it looks like any old Bimini is more often stronger than a middling Midknot.