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A possible remedy for secs at 6 7750s?


freddy333

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Please note - I am unable to provide this service to members.

Last weekend, I may have come up with a possible band-aid (temporary fix) for secs at 6 7750s that die prematurely as a result of the drag & friction/wear caused by the additional gearing required to relocate the running seconds to the 6 o'clock subdial position. At least, those movements that do not have badly grooved pivots.

For some time, I have been toying with the idea of using powered graphite (a dry lubricant used to lubricate locks, control cables, etc.) instead of the standard oils normally used in watches or clocks to lubricate the plate & pivots for the extra gears. As Ziggy pointed out in his excellent reviews of the Asian secs at 6 7750 (if you own or are considering a watch with one of these movements, these are MUST READS), these movements usually leave the factory without any oil being applied to the gearing used to relocate the running seconds from the 9 to 6 o'clock subdial position. This is likely done because the natural surface tension of a liquid (oil) adds a significant amount of drag even while it is lubricating. So the factory apparently chose to assemble this section of the movement completely 'dry', which of course leads to premature wear & breakdown of the movement, as many owners have reported.

Ultimately, the only proper remedy, as Ziggy also suggested, is to jewel the pivots on which the gears run. But that is not a realistic option due to the amount of work & costs required to retrofit a movement this way. But for some time now, I have felt that an alternative workaround might be to use a dry lubricant, which would add little or no additional drag to tax the already overtaxed secs at 6 7750 engine. Powered graphite, being a dry lubricant & one that is often applied as a very thin (1 molecular layer deep) film, seemed just the ticket. The epiphany moment came when I recently read that Jaeger-LeCoultre engineers use powered graphite in the mainspring barrel of their new Master Compressor Extreme Lab, the world's first 'lubricant-free' watch. So I decided that if powered graphite is good enough to be used in this JLC, it is probably worth a try in our dry 7750s.

Anyway, last weekend, I was asked to see what I could do with a friend's 3-month old Daytona rep that recently stopped running. To be sure the problem was related to the extra secs at 6 gearing & not something else, I removed the extra gearing for the running secs & the movement sprang to life. When I reinstalled them, it ran for a bit & then came to a sputtering stop. So it was pretty clear that the extra gears were the problem. Upon closer inspection, I found that some of the gears had actually ground grooves into the posts they are fitted onto. Of course, this is what happens when you have 2 dry metal parts grinding against each other over a period of time. So this watch already had additional problems beyond the inherent design shortcomings. But, still, since I had the thing disassembled & it was little more than a pretty door stop in its present condition, I thought it was time to test my premise about powdered graphite. So I removed all of the extra gears, cleaned the surface of the bridge with denatured alcohol & then applied a very light layer of powdered graphite to the areas highlighted in red, paying particular attention to the posts (marked with blue arrows), which is where most of the friction & wear occurs (note -- this stuff is EXTREMELY messy & VERY difficult to remove from anything it comes into contact with -- a curse & a blessing -- so be VERY careful when you apply it)

poweredgraphite7750.jpg

Now, as anyone who has ever used this stuff knows, the trick with powdered graphite is that you only need a vapor thin layer to create a very slippery surface. So after I applied the graphite, I used a soft Viva paper towel to remove as much of it as I could. Are you getting the point here? The layer of graphite left on the metal is so thin that it will not 'bridge' between the plate & gears the way oil does, so there is no additional drag on the motor caused by the lubricant itself, as is the case with standard liquid oils.

After reassembly, the watch ran. And, according to its (happy) owner, has been running without a problem for the entire week. Here are a couple of quick pics I just took of the graphite test watch next to mine just minutes before the happy owner left with his (still running) watch

poweredgraphite_black010a1.jpg

poweredgraphite_black2006a1.jpg

Of course, it is much too early to suggest that graphite is a permanent solution or one that will fix every dead 7750, since some of these movements will start to run for awhile after the plate & gears are cleaned. But I would definitely encourage others to try powdered (not liquid) graphite to see if they have the same results.

____________

By the way, those of you with black dial Daytonas, this black strap with white stitching looks quite fetching on this watch. It is the first (and, so far, only) strap I have seen that looks good on a 116520. I might have to pick one of these up myself.

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You are welcome, DuDro.

One caveat I need to add -- It may have been something I did inadvertently or a quirk of the Asian 7750 design, but sometime while I had the movement apart, the chrono hour totalizer became afflicted with the same 'creeping' problem that I have had on 2 others (when the chrono is OFF, the hour totalizer hand runs). In the case of my watch, the problem began after I just uncased & recased the movement, without touching anything other than the sides of the plate. The problem is definitely related to the reset mechanism (just a spring & a couple of levers & gears) and I have rebuilt them so many times that I could do it in my sleep (believe me, I have), but I am still not sure what causes the problem in the first place. My guess is that the nylon brake that is normally in contact with the hour totalizer gear (when the chrono is OFF) is either in marginal condition when it leaves the factory (even though it looks fine) or one of the levers is shifting in position during casing & that is moving the brake off the gear, which then allows the gear (and subdial hand) to move when it is supposed to be held in place.

The point I am trying to make is that while it is theoretically better to apply the graphite when the movement is new (before any wear/grooving can occur), you run the risk of ending up with a 'creeping' hour totalizer, which effectively causes more problems. So you need to take that into account when considering this. But if your watch is already dead, presuming the dry gearing has not damaged the pivots too badly, this procedure is definitely worth a try. After all, if you have to freeze anything, I would rather freeze the hour totalizer hand (which would leave the watch looking absolutely normal when the chrono is not in use, which is 99% of the time) than the running seconds hand.

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huh....this is really interesting freddy :g:

i'd be interested (as i'm sure most people would) to hear ziggy's thoughts on your idea....

@whoever's watch freddy worked on, it would be interesting to see how the watch fares over the longer term.....

regardless, thanks for sharing freddy :victory:

deltatahoe

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i'd be interested (as i'm sure most people would) to hear ziggy's thoughts on your idea....

Ziggy, like the 2 other watchmakers whose opinions I respect, did not feel it would work & they may be proven right over over time. But, for now, I think this is something that merits further examination & I hope others will give it a try. I just do not work on enough of these to be able to justify a solid claim either way. But, as in medicine, when demise is a high probability & the orthodoxy have nothing to offer, you have to start thinking out of the box & be willing to go against the grain. So all I am saying is that if you have a boat anchor that you paid good money for, this solution is definitely worth a try. What have you got to loose?

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WOW. This is so encouraging... means my Ingy Chrono will come back to life again!! Thanks for the great info!

However, where do we buy that Graphite Lube? I saw it came with spray cans... is that what you used? Just spray on the areas? Or do you use a brush to apply it?

Work or not, definitely great information here.

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However, where do we buy that Graphite Lube? I saw it came with spray cans... is that what you used? Just spray on the areas? Or do you use a brush to apply it?

Do not use a spray. That contains a liquid medium, which is just the thing we are trying to avoid here. The powdered form usually comes in a small plastic tube. I got this one from my local automotive parts store, but you can probably also find them online from many different vendors

poweredgraphite.jpg

Again, I cannot emphasize this enough -- powered graphite is VERY messy & a vapor thin layer is all you need (or want), so it would probably be a good idea to wear gloves when working with this stuff. Otherwise, you are likely to end up with black, slippery fingers for a few days (graphite embeds itself into the surface of whatever it comes into contact with, which smooths the surface making it sleek & slippery, and because of this, it is very difficult to remove from clothes or skin -- soap does not do a very good job).

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This is VERY slippery stuff i assure you all. I wonder if it would stay in place inside a watch movement? It sure could make a heck of a mess in there. I wonder how long the layer of graphite would last before it wore off? A "vapor thin layer" might not last very long. Sure seems like an interesting idea anyways.

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Please keep us posted on the health of your friends watch. I ahve a seconds at six and the second hand sticks in the same place bringing it to a halt. I am considering pulling the extra gears but would give this a try first.

If it is sticking or stopping at the same point every time, the problem may not be related to the extra gears. The hand itself may be coming into contact with something else on the dial. Maybe 1 of the index markers or 1 of the other hands. I would check that possibility 1st. Usually, if the problem is due to the extra gearing, the watch stops at different places.

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If it is sticking or stopping at the same point every time, the problem may not be related to the extra gears. The hand itself may be coming into contact with something else on the dial. Maybe 1 of the index markers or 1 of the other hands. I would check that possibility 1st. Usually, if the problem is due to the extra gearing, the watch stops at different places.

That is the first thing I am going to check because it does stop in the exact same spot everytime. If that does not work, then I will try the graphite and if that doesn't work, freeze the hand and wait for a better movement to fit the watch. Shame, ran great for a long time and is one of my favorite pieces.

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The broken sec@6 that i recently bought runs for about an hour (after full winding), then starts to lose time, then it stops randomly. I wonder if its too late for some graphite treatment. This mod is way beyond my skills so im not gunna attempt it myself. I can take a watch apart but cant always get it back together hehe. Those little hands are impossible for my big shakey fingers to reinstall :)

dizz

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My recommendation against using these watches as daily wearers has nothing to do with the graphite fix. I just agree with Ziggy & feel that the extra gearing adds too much stress on the movement for daily use over long periods of time. This graphite treatment is meant as a band-aid, not as a cure for an inherently unreliable design. I am convinced that 1 of the reasons none of my secs at 6 Daytonas have died is because they are rarely worn (but I do manually wind them on a regular basis). And I think the same thing will eventually prove to be the case for these watches that have been resuscitated with powdered graphite.

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