A short video showing how to apply cotton on a chanter string.
In this video the wheel has been rosined already.
First: lift the other strings and remove cotton from the chanter string.
Then, adjust the string pressure until it plays a somewhat weak note. Rub the rosin block against the string while lifting it from the wheel with your fingers.
Be careful not to damage the string, especially with metal wound strings.
Liquid rosin is not needed, solid rosin works just as good and you only need a little bit of rosin on the string.
Take a very thin piece of cotton and spread it out until it has the width of the wheel. Now use your left hand fingers to lift the string, slowly feed the cotton under the string while rotating the wheel forwards and bounce the string on to the wheel, you may twist the string a little and help the cotton to wrap around the string if necessary. Make sure the cotton is spread out evenly.
Play the keyboard and adjust the string pressure at the bridge until each note on the keyboard plays in tune and without too screeching.
A thicker drone string needs a little more cotton. Too much and uneven cotton will cause intonation and screeching issues.
Have fun!