I`m beginning to think that mainsprings do not store very well. I`ve tried to replace one in a Waltham 83 Crescent St. movement. Up to the present, 4 springs have snapped when applying some winding power & I`m tempted to bin the remaining 2 I have left & buy some "new" unbreakable ones. Any thoughts ?

Buy new ones.

Mainsprings have a "life of their own". The Waltham factory replacement springs you pictured should be OK unless they are rusted. One thing . . . they WILL BREAK if you install and (try to) use them WITHOUT CLEANING!

Many of these springs were coated with a preservative stuff that becomes quite sticky and will force a break unless it is cleaned off.

This is the nasty surprise I got some time ago from some swiss made mainsprings bought on ebay, obviously stored in less than ideal conditions.

The spring Peter shows is an excellent example. If you insist on popping those out of the retaining ring (they explode) . . . wear saftey Glasses

Great Post Guys. This brings up a Question for me. I don't have a problem replacing a main spring in Most watches. But, what about long term storage of very old or rare watches ?
Should we wind them once in a while ?
Should we not fully wind very old watches ?

Thanks Jack

Jack I would give them a wind. Another factor with springs is that they tend to "set" in position if left too long. If you happen to find a 100 year old watch that has set unused for many years you may find the spring breaks upon winding. I am not an engineer but I have worked on a fair number of double barrel shotguns from the 1870-1940 period and their springs, although flat springs, were subject to breakage on occasion.

Thanks Deacon.
I understand the shotgun thing very well. My other interest is exposed hammer SxS shotguns.
We still shoot them now and then with black powder reloads. I'll continue to wind the really old ones now and then. But I have to admit that when I do I kind of hold my breath......
I would'nt know how to begin repairing a pair cased verge english watch...

Jack I share your interest in hammer shotguns and as far as the verge fusee goes I would leave it unwound and just admire it! It takes a specialist like Chris to do those or a very talented man like Dave Abbe if you can con him into it!

quote:

Many of these springs were coated with a preservative stuff that becomes quite sticky and will force a break unless it is cleaned off.

Thanks for that advice Dave. I had a watch that was acting strange after replacing the spring. I cleaned it, lubed it, put it back in, running like a champ.