watchmakers question

[mikeCM21]

cleaning the maybe 50 year old pendulum clock, while in the alcohol bath, both, the mainspring and chimespring snap.

any reason to believe that removal of old, gummy machineoil residue "kills the spring"??

Or do I need to call ghostbusters to get my grandfathers ghost out of my house??

[SGW]

I can't see how it would matter. I assume you had the tension off the springs while you were cleaning the movement.

[mikeCM21]

both were under tension, I wanted to use spring force to turn the wheels and "agitate"....

both failed within an hour, about 1/2 wound, not at the maximum tension....

[lunkenheimer]

I'd guess that the coils were stuck together by old oil, and didn't slip evenly as the old gunk dissolved, causing overstress. It's just as well that they failed, though, because they probably would have let go soon after you finished reassembling it anyway...

[Evan]

Methyl alcohol is corrosive to steel. It can induce stress corrosion cracking and will make existing microcracks expand catostrophically. The correct cleaner to use is kerosene or "white gas" AKA benzine in Europe.


BTW, I don't advise using WD40 to clean it, or, if you do, don't bloody well tell anyone.

[This message has been edited by Evan (edited 03-08-2004).]

[J Tiers]

BTW, I have never had alcohol of any kind do a credible job of removing any oily substance other than animal based types.

Now, kero, and some of the other solvents (paint thinner, etc) have done well.

If I recall, alcohol is a polar solvent, and relies on attaching to a polarized molecule, but mineral oils are non-polar. Animal oils on the other hand are often polar.

So If I remember correctly, alcohol shouldn't work on mineral oils.

[docsteve66]

I replaced springs in windup phonographs (back in a time and place where they were the prime source of music in homes). the springs often broke after long periods of no use- especially if left wound. A short while ago I put a spring wound morse code machine back to work. WOrked fine a few days and spring popped. I had not been wound in near fifty years (so far as I know). NO rust, original grease still looked and felt good. The spring broke near the inside fastening, but NOT right on the fastener. I think I felt "rough" spots on the spring along the spring, I think it would re-break were i to shorten the spring.

Its my opinion that springs left un flexed for years develop cracks and it is just a matter of time before they part. I speculate that yours were flexed during removal and were just waiting to be flexed some more and then they would break. No stresses involved in your work. I have three .22 revolvers acquired by gift in 1960. The one I loaned out (sorriest of the lot) is still operable- the other two have broken hammer springs and those springs just failed while stored- again no flexing and no rust. My theory fails when you consider all the guns and spring wound clocks and phonographs that were stored for years and resumed work and are reliable.

[mmambro]

I have restored quite a number of clocks from the 18th and 19th centuries.

The cause of mainspring breaks has always been a topic of debate. The quality of steel and heat treatment of the spring can be quite variable. This is further complicated by the fact that one never knows how the last guy fixing the clock or over zealous winder-owner has treated it. Even tiny spots of rust can lead to failure. The ends of the springs where the central portion engages the winding square or the free end is anchored may not have been tempered properly. Anchoring points should have only rounded corners, the hole in the tail of hole type springs must be the correct distance from the spring end; the barrel hook must be properly formed. I carefully unwind and very carefully examine the springs from the clocks I work on. My experience except for one clock has been that the springs break at the free end. The one exception was a mid 1800’s French carriage clock which had both the time and strike springs shattered in multiple fragments, like a piece of broken glass.

I don’t know what type of alcohol you were using, but “rubbing” alcohol is not very good at displacing water in the venue you describe.

A solution containing ammonia and soaps is the traditional bath used for cleaning clocks.

May I respectfully add that “cleaning” the clock in any solution as you described is probably the worst thing you could do to it. I really needs to be disassembled, the pivots reconditioned, pivot holes cleaned and bushed as these are the bearings. You would be surprised at the amount of persistent dirt and grime (read lapping compound) that remains embedded in pivot holes even after plates of disassembled clocks are ultrasonically cleaned in special solutions. (I don’t used this method anymore as I found it an unnecessary step for clocks as I often had to do it by hand anyway. I never used this method on valuable clocks.).
Had cleaning the clock using this method worked and the clock ran, the pivots would have been lapped and failed prematurely.

OT but interesting:
An interesting article by I believe a metallurgist that appeared in one of the British horological journals a number of years ago surprised me. He stated to my surprise that the reason for spring to become “set” in a barrel was not whether or not it was left in the wound or unwound state, but related to the number of cycles of winding and unwinding it had experienced.

I don’t recall if he mentioned whether the stresses in the spring leading to breakage follow the same pattern. I have found by practical experience though, clocks which have been over wound for years have good healthy springs which did not need to be replaced. My own English bracket clocks form the late 1700’s have their original or very, very old springs as near as I can tell.



[This message has been edited by mmambro (edited 03-09-2004).]

[andy_b]

my uncle picked up an old wind-up clock mechanism at a flea market one time and gave it to me because he knew i liked old machines. i was going to take it apart and clean it and put new springs in, but never got around to it (plus it was very badly worn). when i stopped at the local clock repair shop to find out what size new mainspings i needed, the repair man showed me where the mainspings were broken in many places and were basically just held together by the outer few windings and all the caked-on oil. my guess is that your clock had a similar problem and as you dissolved the old grease, the spings just fell apart.

andy b.

[docsteve66]

All of societies ills trace back to electronic/electrical timepieces.

What is as interesting for a 10 year old boy to play with as an alarm clock that "almost runs"?

With the advent of the non mechanical stuff, there are no gears, no "escapements" to defeat and watch the gears whirrrrr. No wonder so many bored kids. Wrist watches are too small, pendulum clocks too expensive. We need dollar watches and two dollar alarm clock again. And don't allow TV to be playing while the clocks are disassembled.