Over the past year a number of anglers across France have asked me what I thought about using fluorocarbon lines for general coarse fishing. I have given vague answers, saying that while fluorocarbon has been extensively used by fly fisherman for leaders and specimen barbel anglers in particular, as a main reel line, it hasn’t been that widely accepted by the rank and file match angler. However, there are some top anglers using fluorocarbon lines on a regular basis and in Italy it has become the ‘obligatory’ line on their hard and clear rivers. However I think it is fair to say that the majority of matchmen stick with whatever make of nylon monofilament they have confidence in, this also included me! Hooklengths are such a personal thing, you need to build up a relationship of trust with a hooklength nylon, and this can take time. Once an angler finds a line they like, they are reluctant to change, or experiment too much. Here, of course, was the underlying cause of my vague answers to questions about fluorocarbon… I couldn’t really give my opinion of fluorocarbon because I simply had not properly tried it myself!

As a journalist I knew that this was really not good enough. People wanted to know about these lines and I hadn’t taken the time or trouble to try them out. So to rectify this oversight I conducted a test session on one of my local lakes.

I decided to fish with two identical rigs… same float, shot and elastic… except for the hooklength! On one rig I set up a 0.10mm fluorocarbon hooklength and on the other, a mono of the same diameter. The results were interesting and surprising, more of which later. However, there are probably many of you who don’t really know much about these lines for coarse fishing so here is a brief introduction to them.

What is fluorocarbon?
The term ‘fluorocarbon’ refers to any compound of fluoride and carbon, that much is simple. The line itself is actually made from a chemical resin known as polyvinylidene flouride (PVDF). The manufacturing process is similar to that of all our normal nylon monofilament line. The PVDF starts it’s life as plastic pellets, which arrive in the factory where they are then fed into heating tanks and melted down. The liquid plastic is then extruded through a large nozzle, which forms a continuous strand of sticky glue, much like plastic. This strand is rapidly cooled in water to help align all the plastics molecules in the same direction. The line is uniformly thick at this stage and to obtain the different diameters it’s run over heated rollers and gently stretched and thinned down until it reaches the required thickness. It’s then finally cooled and loaded onto spools ready for shipping out to the shops.

What are its characteristics?
All this technical knowledge is probably more than most anglers really need know. What we are more interested in is what it does in a fishing context, rather than in a chemical one! Fluorocarbon seems to have several advantages for most anglers, which we’ve laid out below:

Visibility in water
This is the main claimed advantage of fluorocarbon lines. They are supposed to be invisible in water. What this means really is that fluorocarbon lines refract light in a way very similar to water, making the line almost impossible to see once in water. It’s been this main advantage, which has converted so many fly and specimen anglers over to fluorocarbon.

The scientific bit!
To understand the water visibility aspect a little better, scientists use a measure called the Refractive Index. A material which has no light refraction scores 1 on this index and high refractive values are over 2. Water has a refractive value of 1.33. Monofilament has a refractive value of around 1.6 with braid much higher at 2.1. Fluorocarbon comes in with a refractive value of 1.42, much closer to that of water, which is 1.33, therefore making it very difficult to spot once immersed.

Sun and water proof
Unlike normal mono, fluorocarbons don’t suffer from direct sunlight and are water resistant. Both braid and mono soak up a certain percentage of water during fishing, making them slightly heavier. This ability to soak up water in braid and nylon is not totally negative because when you tie a knot, the line swells slightly around it making it just that little bit more secure.

Abrasion resistance
Fluorocarbon is far more resistant to abrasion than other lines. They have a tough exterior surface, which is hard to chip or crack. This could be quite useful when thinking of it as a reel line, unfortunately most coarse anglers tend to use ‘flouro’ purely for hooklengths at present. However many pole anglers have found its use as a rig line exceptional as it holds up well to having shot nipped on and, if careful, moving it on the line.

So why aren’t we all using it?
Having read this you may be wondering why every angler isn’t using fluorocarbon line? If they are almost invisible, what is stopping us using 3kg hooklengths for all of our fishing? There would be little chance of losing any bonus fish, you would think! Well, there are one or two downsides with fluorocarbon, which need to be understood before I tell you about my test.

Breaking strain
The stated diameters of fluorocarbon give a relatively low breaking strain compared to their hi-tech mono cousins. Fluorocarbon’s breaking strain can be nearly half that of standard mono.

Stiffness
Another common criticism of fluorocarbon is that it is very stiff and wiry. I must confess that this seems to vary between manufacturers. The Drennan fluoro I used for the test was surprisingly supple to the touch, however others can be more brittle.

Knot problems
This seems one of the main causes for concern when using fluorocarbon lines and there are two areas of difficulty which anglers seem to encounter. The first is directed at the strength of the knots themselves. Fluorocarbon has a reputation for slipping on the knot and as I mentioned earlier, this may be because it doesn’t absorb water and therefore doesn’t swell and allow the knot to bed down. To overcome this, many specimen anglers have taken to applying a tiny dab of super glue to the knot in order to seal it. This is something I doubt a match angler would bother with because it would prove fiddly and time consuming. A blob of glue may look fine on a size 6 hook but it would be well over the top on a size 22!
The second problem seems to be is possible damage to the line when you pull the knot tight. Fluorocarbons can be sensitive to (KNOT) friction and a lot of anglers warn of how carefully you have to pull knots together to avoid damaging the rig line.

Armed with all this ‘fluoro’ knowledge I decided to put it to the test against standard mono and see just how effective the line was when it came to actually catching fish. My idea was simple, I would fish one swim all day but with two almost identical rigs. Same float, same shotting, same elastic… everything identical except the hooklength. One would have 0.10mm mono on and the other 0.10mm fluorocarbon. My idea was to constantly change the rigs throughout the day looking for any differences. Would I get bites quicker on one rig than the other? Would one rig sort out a better stamp of fish than the other? Would I loose fish on one rig and not the other? In reality I just wanted to find out whether using a fluoro hooklength would make any difference to my fishing.

The venue
I had been talking about these lines with Nicolas Beroud before my test and he felt that it would probably only make a difference when fishing up in the water in bright sunshine. Fair enough, but most of us do not fish in those type of conditions. I wanted to see if it would make a difference to ‘normal’ situations. I therefore chose a fairly deep lake, about 3.6m deep, which contained a good head of small roach and perch but also a lot of larger bonus fish. These were small carp, tench along with some really big crucian carp, averaging well over a kilo each! These bonus fish could prove vital to the test as I wanted to see how the lower breaking strain, and possible knot problems associated with fluorocarbon, would react to any hard scrapping carp, tench and crucian’s that came along.

I fished the venue at the beginning of October after a couple of cold nights, which caused a little of the colour to drop out of the water. This I believed may give some slight advantage to the fluorocarbon. One final thing to note about the venue… there was a slight flow on the lake so both rigs were set up with 1 gram floats to combat the tow.

Feeding
I often fish this venue in competitions and use pellets to purely target the big fish. However, this was something I wanted to avoid here because I needed to see how each hooklength affected bait presentation and then which one sorted out the better fish, rather than have the bait do it for me.
I decided on a chopped worm and caster approach, which would not only attract small fish into the area but also some big fish as well. I mixed up two kilos of roach groundbait, with plenty of Coco Belge (a sort of chocolate groundbait) and black Terre de Somme. My idea was to ball in ten large jaffa’s with a few casters and worm at the start then feed a more concentrated chopped worm and caster in soil throughout the day with the pole cup. There was an autumn mist hanging over the lake with the promise of sunshine later in the day as the balls were made up and fed into the gloom at 11 metres. It was now time to concentrate on the business of the day, the hooklengths!

Fluorocarbon and knots
I tied both the nylon and the fluoro using a Sensas loop tie. On both loops I gave two turns on the tier and pulled tight, moistening a little. The nylon was finished perfect, as I would have expected, but what about the fluorocarbon? I decided to examine the line closely to see if there were any signs of damage below the loop and to my surprise there was none. The loop was perfect, it sat well and neatly on the line and there was no marks on the line… a good start. I then tied another set of hooks, this time using a Matchman hook tie.

When using a hook tying gizmo you do need to be careful as you pull the line through the spirals of the whipping knot to get the hook tight. I was using a size 16 Kamasan B611, which will allow me switch easily from caster to worm throughout the session. Once more there was no sign of damage on the fluorocarbon. The hook sat perfectly on the line with no friction marks or damage above it. So far full marks to fluorocarbon!

Conclusion 1
There was no sign of damage on my chosen fluoro hooklength. The line proved easy to work with and did not feel stiff or springy. The results were first class and there was no difference at all between the quality of knots between the nylon or fluorocarbon.

The start of the session
Having left the swim to settle for 15 minutes it was time to start fishing. My first put in was with the mono hooklength and double caster on the hook. I lowered the rig down slowly over my pre-baited area until the float sat perfectly and then waited. It didn’t take long for my first bite and fish… a carp of just over a pound, a good start. Back out on went the fluorocarbon rig, again with double caster. I waited no more than 15 seconds before it went under only to miss the bite. I shipped in and found the casters completely untouched. The process was repeated on the next two put ins before I finally connected with a fish, another carp. I went straight back on the mono rig and waited a couple of minutes or so for a bite, then got a fish. Back on fluoro, the float barely settles before going under again…. and the casters are once more untouched. This pattern was repeated over and over again through the early part of the session. I found I had to wait for a bite and a fish on the mono, whilst the flouro produced instant bites, but no hooked fish… what was happening?

It slowly dawned on me that I seemed to be getting line bites on the fluoro but not on mono! I hadn’t expected this to happen, which is why it took a while to figure out! But then I understood what was happening, it was so obvious, if I’d wanted proof that fluorocarbon was almost invisible to the fish… this was it. I’d been getting liners on the fluoro because the fish couldn’t see it!

Conclusion 2
If there are a lot of fish in your swim then it’s more likely you’ll get more liners on flouro than mono. This is not really an advantage as line bites can be a nuisance and time consuming. But it does make sense… if the fish can’t see your line, they will inevitably swim into it!

The session develops
As the day went on the swim settled down. I think that the initial feeding had pulled in a lot of fish, which caused me the line bite problem. As the session developed the bigger fish settled over the feed, pushing the smaller ones away. I started catching good quality crucian’s with the odd tench and small carp thrown in. The crucian’s were all quality fish and fought very hard, testing the resilience of both the fluoro hooklength and knot itself, even with its lower stated breaking strain. I felt the hook knot would be a point of weakness on the fluoro rig as I’d read a lot about knots slipping. The Kamsan B611 hooks I was using are strong and have a shiny surface with a relatively small spade end and I fully expected to lose a fish, leaving me with just a small twizzled bit of line where the hook had slipped off. But it didn’t happen. I even managed to foulhook (not surprisingly) a couple of fish and the hooklength held up perfectly… another positive mark for the fluoro!

Conclusion 3
On the day of the test I experienced no problem with either the fluoro or the mono hooklengths from lost fish or broken line. I didn’t hook any of the really big carp or tench that live in this lake but had I specifically targeted these larger fish I would not have been using an 0.10mm hooklength, more like 0.14mm straight through. However given the quality of some of the crucians and tench, both lines performed equally well.

Which rig got the bites quickest?
Once the line bites had calmed down I went through a period where fish came steadily to the caster. These were a mixture of roach, small carp and crucians. During this spell I was convinced that the fluorocarbon rig was getting me bites quicker. I’d been switching between a buried single caster and double caster and my feelings were that the fluoro was proving the more effective rig. However, there was not a lot in it as I was catching well on the mono as well. My overall opinion though was that I was getting bites quicker on the fluoro. I was now beginning to think that I had the report wrapped up when the fishing went quiet about 12 o'clock. The bites slowed on both rigs and I was eventually waiting three to four minutes for a fish. Deciding to change things a bit I started using pieces of worm on the hook, varying between a small section and half a worm. I started to pick up a few perch, mostly by inching the bait across the bottom of the swim.

Once I started moving these pieces of worm across the swim there seemed no appreciable difference in the speed of bites between either hooklength. In the early afternoon the tempo picked up again and I started taking good crucians on a worm and caster cocktail. Once again, the bigger hookbait produced no marked difference in speed of bites to either rig. I was gradually losing the impression that I’d had earlier that the fluoro rig was getting me quicker bites! I tried going back to single or double caster and just caught small roach, it was the bigger baits that were now taking the bigger fish and meant that it was hookbait, not presentation, which was sorting out the quality of fish.

There was still one area where I expected the fluorocarbon to do well, but unfortunately the results had proved inconclusive. This was fishing on the drop, or just after the float settled. The fish in this lake, crucian’s especially, are very well educated and notoriously finicky. I’d wanted to get the bait presentation as natural as possible through the bottom layers. Throughout the day I’d carefully lowered both rigs into the water, to get the best presentation through the water having set the bulk shot fairly high on both rigs. I would have expected the fluoro to get me a few extra bites on the drop, or just as the bait settled, but this proved not the case. I managed to get a few bites straight away on both rigs but generally caught the majority of fish throughout the test right on the bottom.

Conclusion 4
While the fluoro did produce bites quicker when using a static caster hookbaits, once I switched to a slightly larger hookbait and started moving it there seemed no difference whatsoever. This should not be too surprising as the main invisibility advantage of fluorocarbon would come into play while fish are inspecting the bait. Once a larger moving bait was used, the fish seemed just as attracted to it without the need for such careful inspection.

THE FINAL VERDICT
By the end of the session I felt that I’d learnt a lot more about fluorocarbon hooklengths. But, as in all good courtroom dramas, before I reach a verdict on fluorocarbon hooklengths I should sum up what I believed were the main learning points of the day.

The POSITIVE points were mostly related to how easy the fluoro line was to work with. Despite previous stories of wiry lines, damaged knots and potential fish loses, none of which proved true, I’d given the line a good test. I’d caught plenty of fish for most of the day and it had shown no signs of weakness or knot problems whatsoever. I went away confident in the knowledge that fluorocarbon was more than capable of holding its place as a dominant hooklength in the marketplace especially during winter periods or on hard fished waters.

On the NEGATIVE side, the line bites were annoying and would likely to prove more of a problem during summer fishing on fish packed commercials.

Evidence as to whether the fluoro line caught more fish on the day was rather INCONCLUSIVE. I believed fishing single and double caster on fluoro line gave me a slight edge, but not by much. There was certainly not enough evidence on this session to say categorically that I caught more fish thanks to the fluoro line.

The key question after this experience is, will I be using fluorocarbon hooklengths again? The answer is certainly, but not in every situation. I will be using it this winter for my canal fishing where the fishing is hard and I think that the fluoro will give me some advantage. I will also be using it for silver fish when I go fishing on clear rivers. The same goes for bleak fishing up in the water and possibly feeder fishing for skimmers.

However I will not be entirely abandoning mono for the bulk of my fishing as I spend lots of time targeting bigger fish, especially in competitions. If I’m going to spend an hour waiting for a bite from a 4lb chub with a lobworm on the hook I‘d rather be using a more conventional strong hooklength than an invisible fluoro one with half the stated breaking strain. It’s the same for a lot of matches where I need to catch big nets of quality fish perhaps on say pellet. I’m not convinced that fluoro will give me much advantage with bigger hookbaits, while the line bite issue could be a major disadvantage in these matches.

However, my overall verdict on fluorocarbon at the end of this test is POSITIVE. I liked using it, the test gave me a lot more confidence and I can see a number of situations, especially on the more difficult side of fishing, as the Italians have shown. With winter approaching and fishing getting harder, fluorocarbon just might get you those few extra bites to cheer up a gloomy December and January afternoon on your local water. The fundamental thing about fishing I have learned from my big test it is this… if you don't try something new it you will never know if it works or not!