A topic often discussed on forums is how to save ones Hang from rust problems. And although there is a recommended and proven solution, often means like bee wax, gun oil, olive oil or a number of other fluids are in use. It seems that a large group of owners of older Hanghang are not aware of the PANArt Hang cleaning fluid recommended since 2009.
Read more on the Hang Forum:
Hang cleaning and corrosion protection 
Salve vorrei sapere a che indirizzò si invia la lettere e cosa bisogna scriverci.ma viene a costare tanto un hang.
Hi Allessandro,
read this: News about Hang and Gubal