I have a pair and the tip of the feather keeps slipping out at the most undesirable time, causing a few choice words to come from my mouth. I have changed the small piece of rubber that covers the one side of the pliers many times and tried the covering the opposite side as well but the tip still keeps slipping out. Any other suggestions? If you use a pair of these what brand do you have and have you had any problems with them.
Rodney
I have a pair, but never use them. The answer for me is saddle hackle. Hold on with my fingers and wrap.
Try cotton (not nylon or waxed) surgical tape. You can split it to the width you like and it will be tacky.
I use mine all the time. When I first got them, they slipped off the hackle, yes at the worst time. I tried a couple other things, slipped over the ends. At last I stripped a one inch piece of rubber insulation off a 12 gauge copper romax (regular household electrical wiring). First I heat one end with a match. Just enough to force it over one of the ends of the pliers. Allow it to cool first, then cut off close to the metal finger. I have found only one is best. It holds for me and is inexpensive. I can not remember having to replace it in over 5 years and I tie a lot. (small flies)
I do not know the brand but is the only way to go when hackling parachutes.
Thanks guys, I will give those tips a try and see what happens. I tie a ton of parachutes and really like using the rotary hacklepliers.
Rodney
Heat shrink or you can get tht stuff in a can for dippin tools. They also make a liquid electrical tape that you can get at HD
Sometimes you got to ‘finish’ making the tool properly.
Hackle pliers are one item that we but that almost always has to be ‘finished’ after you buy it.
It takes a bit of time, but well worth all the agravation it saves.
Properly adjusted, the hackle should not slip or fall out without having to ‘add’ anything to the jaws. It doesn’t hurt to add the coatings, but getting the things properly adjusted FIRST might alleviate the need for them.
First, the jaws should meet absolutely flush. This is the biggest reason for slippage. Check this with a piece of paper. Place a piece of notebook or copier paper in the laws and then try to shift it side to side horizontally. The metal jaw should hold the paper firmly over it’s entire surface. If it’s only holding on a portion of the jaw, you will be able to see that. Take the time required to adjust the jaw so it’s flush. A pair of needle nose plier and some trial and error will fix it. Make very small adjustements until you get it right.
The jaw should be smooth around it’s edges so it won’t cut the hackle. Run a Q-tip around the jaws. If you find any rough spots, sand them smooth with 1500 grit sanding cloth (or polish with a dremel if you have one).
Sometimes the tension is too heavy/light. Adjust this by gentle bending of the jaw arms. On the rotating ones, you can open the jaws and separate them latterally, then adjust them so they hold properly. How much tension is a personal choice. I want to be able to break the hackle with the pliers, some prefer that it slip just BEFORE breaking. Up to you.
After you’ve got you hackle pliers ‘finished’ you can decide to add something to jaws. You probably won’t need to, though, as all these coatings really do is cover up the ‘flaws’ you’ve just repaired.
Good Luck!
Buddy
I recently revamped my hackle pliers by slicing off a very small section of what looks like very small diameter surgical tubing and slipping it over the tip. I’ve been tying a large batch of soft hackles since and haven’t had the partidge slip yet.
Easiest solution is dump them and get saddle hackle. Have never found rotary pliers to be useful and when I do actually wrap hackle, I much prefer the lightest possible style I can find, so I usually favor Dorin pliers or wire clips.
I use Griffin rotating pliers, and they work well enough. Almost all (99.999%) of my hackle is saddle hackle now, so the pliers only come out for the last small length that’s hard to hold by hand. All good advice on adjusting and finishing tools. I saw a ff’ing show video with the owner of Dr. Slick on YouTube. He said that when Dr. Slick scissors arrive from Pakistan, they are in very rough shape, and that they must bend, shape, and sharpen the scissors quite a bit once they arrive in the USA. Griffin tools are born in the USA, so just tweak as needed. 
BTW: I did NOT like rotating hackle pliers when I first bought them, hold or no hold. I did learn to use them, however, and they do have a place on my table.
I just bought the new Dr. Slick Extra Hand Tweezer. It is light enough to hang from the vise, heavy enough to keep tension and holds hackles well.