"Hurda" is any old commodity that can no longer be used for the original purpose it was produced (heavy damage, missing vital parts etc.)

"eski" is simply "old". An eski pair of shoes can still be worn while working in the garden.

It is funny. We also use the word "hurda", but we pronounce it like "hurdı"(so it is plural and never singular). When we say like that we mean in generally "junk". For example "pack your junk (hurdı and come with me". Not so polite, i should  tell, and better say like that to close people, as if it is some humour.