we often read or hear about the water’s surface tension and how it affects fly-leader-fly line floating/sinking abilities and also how aquatic insects can have a hard time breaking through it on their way to the surface and other insects can use it to literally walk on water. often described as some sticky, gluey thing that’s between water and air but what is it exactly ?
since i probably won’t be able to explain it without making any silly mistakes.., i’ll let this silly young lady do it for me !
“Africans do this with mosquitoes to help stop the spread of Malaria, material (soap) is put in the water to break the surface tension. Mosquitoes use water tension to land on the water so that they can lay their eggs. Without the water tension, they sink like that spring.”
so, how does this help us in our fly fishing world ?
apart from something cool to know and yet another example of how amazing water is, if you’re a fisher that doesn’t think that a floating tippet near a dry fly makes a difference and you still catch fish, then this won’t help.
however, if you want to up your game, specially on fish that aren’t on a feeding rampage or on slower waters or on any types of waters and you’re dealing with fish that might be in a mild-alert stage then one of the best ways to have a chance with them is to degrease a good 2-3 ft of your terminal end leader or tippet with sink paste to get it to break the surface tension as soon as the fly alights on the water.
as a reminder, sink pastes are typically made of three ingredients- liquid soap, glycerine and clay powder. the powder acts as a binding agent (it’s also a very mild abrasive that removes a little surface shine from monofilaments), the glycerine keeps the paste from drying out and the main ingredient is as seen in the accompanying videos: soap, which allows the tippet to sink under the surface rapidly and not be so visible and light reflecting and/or create nasty shadows on the riverbed on a sunny day.
if currents aren’t too strong sink paste also greatly helps unweighted wet flies and nymphs to get into the feeding zone without having to weigh down the flies themselves or use split shot or whatever resulting in a free moving, more realistic impression of life to the fly. this last point is no secret but it’s rarely brought up and it’s a real gem to have in your bag of tricks.
since science and trippy often go hand-in-hand, here’s another eye candy example of surface tension experiments,
and how even water itself can be subject to the sticky-gluey barrier.