Top post! Very interesting and informative, and even a little bit of jeopardy to keep the reader on the edge of their seat! :)
I got this on my bench mat the other week, I've always wanted one. This wasn't to stay with me for long, though after sitting waiting for me to tackle it as the owner chose me to do a relume and get it serviced. It was overhauled a year or so ago but had an issue where the chrono would stop at 58 quite often. On the TG the trace would show a fairly large climb in rate at minute changeover as the hand passes 12 o'clock and the minute register ticks over. I thought it would likely be too much tension on the minute counter spring or the chrono arm not striking the teeth on the intermediate minute counting wheel correctly.
It looked really good and I do like these 6139s particularly, not a fan of many others in all honesty.
Hands and dial had some blackening, it wasn't terrible mind you so those who hate to see lume get relumed...look away!
After the removal I got a pretty cool colour and texture. My goal was to redo a vintage look in keeping with the tone and grain of an original, maybe slightly more creamy.
One of the minute markers.
The dial came out really nicely I reckon, got it close to the original look with a bit of an old aged look maybe? Pretty happy anyway.
In different light.
And glowing, but not too bright and doesn't last very long.
Movement was stripped and cleaned and it all went together well, my main concerns being that the power reserve and rates were good and with some testing the watch would sit and keep time and not have any issues with the stallling chrono hand.
The 6139A plate differs from the B and one of these differences is the intermediate minute counting wheel, the B is removable whereas these are staked into the chrono bridge.
Anyway the movement also came out looking really nice.
It was sent back, job done...
However, the owner reported back after a day or two to say the chrono was again stopping. Shit! I immediately thought power reserve, but they were wearing it all day and would have had sufficient power to tick past 12, and so it was back to what I had a suspicion of originally, although I'd given it a lot of attention, and it was that the intermediate wheel here wasn't quite right. I haven't done an A, infact that's a lie I did strip and rebuild one about 3 years ago as a test but I've only done 6138s and 6139Bs recently, and although can be tricky they're really cool to work on and not too difficult at all.
Well, so here we are, it was sent back and I wanted to get a closer look at the minute counter wheel and the intermediate wheel, at which point I had to try and clean it even further to see what was what and how it would perform. The manual shows to stroke it with a brush to see it rotates freely. It ran well again, but soon stopped once I woke in the morning, something clearly hindering it. Well, despite the somewhat better trace on the timegrapher and a less significant jump, even compared to the first overhaul where after testing for a day or two it seemed find, I staked the sucker out, cleaned and reinstalled as this was really my only option, that and a replacement bridge but that isn't ideal.
And so here it is free from the bridge.
I found fibers that had wrapped around the staff and dirt under x35 that was finally removed. I staked it back in place, and this time a little tighter as I wasn't too pleased with the play of the wheel, careful not to overdo it.
Once it was done I could now see it happily wheel itself around with just a puff of air, much better and much more what I would expect. I checked to see the trace and could barely notice the minute changeover affect amp or rate.
At a low wind I tested to see if it would have any issues, as it gets to the third 0 on the display below this is when the changeover occurs. I let it do this for a while and all seemed well. Full wind was giving around 240 to 250+ amp and so I was happy to send it back again, and finally. Lot of learning and testing and it certainly keeps me busy!
https://i.imgur.com/7ek1qsc.gifv
Phew! :)
Proud of the job done here and hope you enjoyed the thread.
Top post! Very interesting and informative, and even a little bit of jeopardy to keep the reader on the edge of their seat! :)
Good work Guy and what a great sympathetic job on the lume
Great post - so interesting to see your work and the challenges you overcome.
Sent from my moto e5 play using Tapatalk
Did you add lume on top of the old (with an oiler) or did you remove the lume batons and strip the old lume off with Acetone, before re-gluing (CS cement) and re-luming?? Cheers John
Just gently scraped the lume from the plots to leave a clean surface for the new mixture.
you need to stop and relax for a while.
maybe shift your focus to other things. like the simple pleasures of working on a 6105 and an A13a.
just a suggestion :)
Great post. Great outcome.
Whoever does not know how to hit the nail on the head should be asked not to hit it at all.
Friedrich Nietzsche