Snip, snip. Hack, hack. A fluffy spray of fibres and thread peering out over the hook eye. Familiar? How easy is it to sharpen fly tying scissors?
 
YouTube has many videos on how to sharpen kitchen style scissors with a sharpening stone. It looks easy. But I could not find the same for delicate fly tying scissors. Typical advice is to send it to a professional sharpener.
 
I had a good candidate – a pair of scissors recently demoted to the wire cutting department. The very tip could no longer cut a slack piece Gordon Griffiths sheer 14/0 thread. This is my benchmark. They don’t need to be able to cut GSP. 
 

I have a cheap very fine 8000/3000 grit sharpening stone.  It creates a hair shaving edge on knives. I am not particularly good at knife sharpening.  The fine grit felt right for delicate fly tying scissors as not much metal needs removing. It would not scratch the blade and also leaves a wider margin for error.

Some tips I gleaned from various sources across the web:
 
– Do not grind down the inside (flat edge). I gave mine a very light ‘polish’ with the 8000 stone to remove any dirt from the surface. You will notice the edges turn shiny showing that the scissors are slightly concave. Heavy grinding on the flat edge may severely impact the cutting action.  On my first pair, I probably took off more than needed. 
– Take the scissors apart if you can. Big scissors that open 90 degrees can remain assembled. Here scissors like Anvil with their purposely adjustable screws are perfect. Many scissors have only the little screw e.g. Dr Slicks. For these you may need a bit of Locktite to hold the screw at the right tension.
– Scissor cutting edge angles range from 90 to 45 degrees. Most are nearer the flatter 70 degrees. Some of the Japanese scissor edges are knives at 45 degrees. Sometimes the two edges have different angles. I kept the same angle as the manufacturer. I do wonder if a knife edge pair would work better on GSP.
 
– Try the ‘Sharpie technique’ to check that you are grinding at the right angle.
 
Similar to sharpening a knife, grind the cutting edge until you form a fine burr on the flat (inside) edge.
 
– Top tip – maintaining a constant angle during the pull is far more important that getting the exact angle right. Failure to do this will create a rounded edge and destroy the cutting action.
 
I find it is easier to keep a constant angle by only grinding in one direction. i.e. pulling. I hold the angle, pull along the stone. Lift it back to the top of the stone and repeat the pull stroke. After 8-10 strokes a burr formed for me. Makes sure the burr runs along the length of the blade by ‘feeling’ the edge with your nail. I found that this formed last at the tip (the most important part).
 
– The burr is critical for creating a sharp edge. This is a fine piece of metal that has ‘rolled’ over the edge. When removed it leaves an ultra fine cutting edge. Stropping (think mean cowboy, knife and leather belt) does this when knife sharpening. It bends the metal burr onto one edge and then the other until it breaks off leaving a razor sharp edge.
 
– Once you have a burr on both scissors edges, reassemble the scissors closed. Do not cut down to remove the burr as this will dull the edge. Instead, apply pressure to the closed scissors blades and then open the scissors to ‘lift’ the burr. Do this a few times and then do some cutting action. I guess that you could also strop the edge like a knife, but the method above seemed to work well.
– For obvious reasons, do not grind down a serrated edge. I did sharpen a micro serrated edge by lightly grinding down the edge as above. Not enough to remove the serrations, but the edge was sharper.
 
– Finally, set the tension of the scissors correctly. They should be slightly loose, and come together at about 45 degrees closed. Too tight and the tips will not cut and you could damage the edge. I start loose and progressively tighten until the tips are slicing apart fine thread. High quality, close tolerance scissors offer almost no resistance during the cut.
 
– GSP is a different beast. Few scissors cut this, and if they do, they don’t tend to do it for very long. I slice it with a blade or sharp scissor edge instead.
 
With one pair a success, I quickly touched other pairs that were no longer super sharp. I was most happy with the pair of large sturdy shears for cutting wires, furs and hard materials. These now trim fine thread even at the tips. Removed a few nicks in the blade too.
 
I wish I had tried this earlier. Easy, quick and would it would have saved me a good number of scissors over the years.
 
Give it a try – but maybe don’t start with your Marc Petitjean’s. If you are throwing these away, I would be happy to recycle them.