Thanks for all the thoughts. Ssomeone mentioned the horse hair acting like barbs or plectrums so it my be possible to clog them up with roisin. If that is the case I'm reluctant to add more rosin and end up making matters worse. I've heard you can wash the hair but this will be the last resort. I could also have it re-srrung as that is cheeper than a set of strings.

Thanks Herge