New to the forum and new to watch collecting in general. Maybe some of you will have an answer to my question. I received a 1967 Tissot Seastar in pieces the other day. By pieces i mean the movement, case, glass, and two screws. After putting everything back together I am finding that the movement is losing time. After a good wind and letting it sit, it keeps great time for about an hour then the movement starts losing time and ends at a half an hour behind compared to my other watches. The funny thing is, it keeps great time after it loses that initial half hour. Any ideas or suggestions to why this is happening?
Some observations to help:
-The movement is a Tissot 782-1 Unadjusted 17 jewel manual wind
Thanks for your help