Monday, December 23, 2013

Tungsten Jig Backs - the case for density.

There is certainly no fishing to be had at present, what with 30mph winds lashing heavy rain against the front door, and little change to the situation forecast over the coming few days. So with a couple of hours to kill, I settled for second best and tied some flies instead. Inevitably they were grayling bugs, and it's ironic that I've tied more weighted nymphs up lately than for some years, yet haven't had the chance to fish any of them yet. Maybe the weather will ease up towards the new year.

So, to the tungsten jig backs I have been experimenting with. We anglers like a bit of tungsten, it's true. At nearly 50% greater density than lead, it allows us to pack a lot of weight onto a relatively small hook, thus allowing a reasonably life sized nymph pattern to be fished at depth in even strong flows. Tungsten beads of various size and colour are the contemporary river angler's staple these days, and it's not uncommon to find dozens of bead headed bugs lined up for duty in the nymph box of any fisherman you meet. However, even tungsten beads represent a compromise in the quest to get small flies down deep; unless you go for a slot-drilled version on a jig hook (popular with many, but not something I use much), then a good chunk of the precious metal mass is lost in the countersinking of the bead back. Obviously we can pack a few turns of lead wire into the back of this cavity before we start the tying proper - and this proves ample for most general purpose nymphing scenarios - but wouldn't it be nice to take things a stage further, to go denser and smaller yet?

Well yes and no. I had an interesting chat with Glen Pointon recently about the effectiveness of his silicone-based Soft Touch Shrimp  (details here). I've yet to get around to trying this pattern, but it's certainly been creating a bit of a buzz over the last year or so. Glen tells me he has been able to watch sight-fished grayling inhale and then reject weighted offerings in the blink of an eye - something you read about all the time, but few of us who fish mucky spate rivers ever get to witness. Interestingly though, when the soft touch version was drifted past the same fish, not only did they take hold, but the kept hold....for much much longer. I don't suppose there's any great surprise in that, but it does raise a number of questions about the frequency with which grayling anglers miss takes - or don't even register them in the first place - due to the fish ejecting the weighted offering almost immediately.

Thinking back to my recent day on the Nith, it's difficult to say whether this happened to me. I think I missed two takes, but it could have been a momentary catching of one of the flies on the bottom, who knows.....and as for offers which didn't even manifest at my end? Well there's simply no way of saying for sure. What I can confirm is that small, very densely weighted bugs proved the difference on that particular day, and I can't think of how we would have got equivalently sized bead heads to grip down sufficiently in the current to achieve the same presentation. The damage was done with the 'McDonald's Killers' mentioned in the previous post, and that's motivation enough for me to look further into the possibilities afforded by moulded tungsten 'jig backs' as heavyweight alternatives to standard countersunk beads. Of course there is nothing particularly new here; I remember writing on this blog nearly six years ago about 'Bidoz bodies' and have used them on and off ever since with some success. However, I'm pretty sure the jig backs usurp even those for compactness as they are a touch wider and lack the ridges and troughs of the Bidoz bodies, which made the latter somewhat difficult to dub over, thus limiting the variations of pattern which could be tied with them. I'd have to get a set of sensitive scales to confirm this (and although I'm a self confessed fly fishing geek, I'm not that sad), but I'd be willing to bet you get more wolfram bangs for your buck with the jig backs.

First things first: where to get them and the appropriately sized hooks. On the advice of Messrs McDonald and Walker, I headed straight for Joel and and furnished myself with some medium and small jig backs in various finishes including copper, gold and plain tungsten. Joel provides a handy hook sizing chart on his website which shows what models of hook suit what size of jig back. At the end of the day, the choice is yours and there are plenty of excellent hooks out there (I'm told Fulling Mill 'grab gape' are very much worth giving a run and are well suited to this type of fly), but I went for the Dohiku 644 shrimp hook, simply because it's one I use already and am quite happy with. So, medium jig backs = #14 hook; small jig backs = #16 hook. Simples!

The basic premise is that you superglue the jig backs to the shank of the hook, using the slot on the underside to locate. The slots are however quite narrow and it means that some consideration has to be given to how you tie your materials in, and in what quantity, because if you work down the shank, tying down tails, ribbing, wrapping etc etc, you just end up creating too much bulk and the jig back won't slot on to the hook at all. To be honest, these are fat, squat little lumps of tungsten anyway, so they don't lend themselves to being heavily dressed lest they end up looking like tiny blobs - something I've found to my cost during initial trials at the vice. Craigie's fly is simplicity itself - thread, tails and a few wraps of nymph skin. The rest is achieved using marker pens, fluo nail varnish and UV cure resin - a streamlined mini-bomb of a fly which gets down deep, quickly, and fishes hook point up in the manner of a conventional jig pattern. I've filled two rows in my nymph box with 'em!

However, we fly tyers are an experimental bunch and I couldn't help but wonder if the template could be applied to some of my favourite trout and grayling nymphs. I've chosen one such for a step-by-step below, to illustrate how simple these things are to use, and to highlight some of the pitfalls I've encountered whilst messing about with them over the last fortnight. A chance to actually fish some of these bugs would be a fine thing, but in the meantime It's exciting to think about the possibilities at least. How would a brace consisting of a McDonald's Killer and a Pointon's Soft Touch Shrimp fare do you reckon? I promise you one thing, I'm bloody well going to find out!

Jig Back Red Tag

Hook: Dohiku 644 #14, 16
Thread: Sheer 14/0
Tail: red Globrite floss
Rib: fine copper wire
Body: tungsten jig back, size to suit hook, copper finish used here.
Dubbing: natural hare's ear
Collar dubbing: chocolate Diamond Brite dubbing

1. Vice the hook. I include the photo below only to show the type of hook profile which is best suited to the jig back. Straight shank hooks just don't look right.

2. Run on the thread. Stick to a fine thread to avoid unnecessary build-up as we need to slot the jig back over the shank later on (used 14/0 here). For the red tag I've used Glo-brite floss doubled up to give 8-ply thickness, which is pushing it about as far as possible bulk-wise whilst still giving a substantial tail. The floss needs to be tied on to the top of the shank, not the side, for the same reason as above.


3. Continue to tightly bind down the floss towards the bend of the hook, to reach a point where when you offer up the jig back 'dry', the thread is parked just behind the butt end. Snip off the waste floss.

4. Add a drop of superglue to the top of the hook shank. I like Loctite Powerflex gel for this as it is more viscous than normal superglue, so doesn't run everywhere and has a slightly longer curing time, which allows us to make sure the tungsten is properly positioned. Drop the jig back on and if necessary, squeeze down into position with a pair of fine pliers.

5. Under normal circumstances we would have preferred to catch the wire rib in early on and bind down the full length of the hook shank. We don't have that luxury here as we are using a relatively bulky material for the tail. All is not lost however - I've found that a short thread taper is required immediately to the rear of the jig back to form a neat transition from body back down to the tail. We can use this taper section to catch in the wire rib. It is only short though, so I give the wire a double 'figure of eight' tying in, before building the thread taper over it, wiggling off the tag end of wire and then adding a tiny dab of superglue for good measure.

6. Dubbing. The jig back is bulky in itself, so any dubbing needs to be thinly spun and tightly applied to avoid the 'blob' look. I've included the stage below because the initial wraps of dubbing can be tricky - the thread wants to slip back down the steep initial taper to the tail, so you need to take a bit of tension off the first few wraps to get the dubbing nicely seated on the arse of the jig back...while still maintaining enough tension to get touching turns so tungsten doesn't show through the dubbing later.

7. Complete the dubbing up into the grooved section of the jig back. I'm introducing a glistery thorax material here, so I've stopped the hare's ear off at about the 2nd groove back, to leave room. Follow up with the wire rib - again, care needs to be taken with the initial turns as too much tension will drag the dubbing backwards down to the tail.....go lightly with the first couple of turns and then bite down as you get onto the body section.

8. Add the thorax dubbing, whip finish and snip off the thread.

9. Nearly there - all that remains is to varnish the whip finish thread and snip the floss tail to length.

Done! Not the most streamlined nymph you'll ever see, but small, dense and with a touch of colour. The conventional red tag hare's ear is a fly which has never let me down. It will be interesting to see if this incarnation proves as effective.

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