What's wrong with the edge of the awn skin of the erhu just bought?

Need maintenance. Erhu has rough skin, which is prone to noise, cracking, scale withering and frosted edges, and needs maintenance. Erhu is a stringed instrument and a kind of huqin, which is bigger than Jinghu. Its barrel is made of wood or bamboo with a diameter of about eight or nine centimeters. One end is covered with python skin or snake skin. There are two products and two strings on the stem, which are arranged according to the five-degree relationship. Used for solo, accompaniment and ensemble. Most of the accompaniment instruments for Tsing Yi singing in Peking Opera have added erhu, which was founded by Mei Lanfang.