• Upcoming updates
    Over the next couple of weeks we will be performing software updates on the forum. These will be completed in small steps as we upgrade individual software addons. You might occasionally see a maintenance message that will last a few minutes at most.

    If we anticipate an update will take more than a few minutes, we'll put up a notice with estimated time.

    Thank you!

Serious verdigris corrosion on Schatz JUM/7

AndyDWA

Registered User
Dec 26, 2013
621
6
18
Western Australia
Country
Region
On a recent interstate trip, I picked up this poor little thing for $10. I couldn't return home without a 400-day clock and this was the only one available in my price range.

I can't imagine how it got in this state but it has the most-serious corrosion I've seen to date on any clock. Other than the barrel, the gear train looks to be in pretty good condition.

I'm assuming I will just dismantle it and set to work with a toothbrush, followed by lots of polish and wax. But is there a "correct" way to deal with this? Do I need to neutralise the verdigris or anything? Will it ever stop?

I have no professional equipment, like ultrasonic, just domestic chemicals, steel wool, various brushes, Autosol and carnauba wax.

I am a little worried about the bottom-left screw on the back plate. It looks ready to disintegrate.

I am yet to see inside the barrel and expect I may need a new spring (and maybe a replacement barrel), but can I win or are my expectations too high?

attachment.jpg attachment.jpg attachment.jpg
 

Attachments

THTanner

NAWCC Member
Jul 3, 2016
2,892
248
63
Carson City, Nevada
Country
Region
Looks like something that had been sitting on a ship in a salt water harbor for awhile.
 

AndyDWA

Registered User
Dec 26, 2013
621
6
18
Western Australia
Country
Region
Yes. I used to have coral reef aquaria some years ago and this looks like the sort of thing that used to grow on the glass :)

I checked today and it doesn't wind. So either the spring or the hook is likely broken.
 

victor miranda

Registered User
Jan 13, 2017
374
48
28
Baltimore
Country
Region
that is quite the project.

the corrosion will be spots and circles in the brass when you have
it mostly removed.

I expect you will need to repivot at least a few arbors.

I am very fond of Jum/7 clocks and I think you should consider it as parts.
when you find the proper dome for it, you are very likely to get a clock under it.

I'd clean it as practice and to stop the erosion.
:-D and then you will have a cute 'basement clock'

victor
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
49,469
2,925
113
North Carolina
Country
Region
Wow! Maybe it fell into a salt water aquarium at some time in it's life.
 

Dave T

NAWCC Member
Dec 8, 2011
4,377
439
83
NC
Country
Region
I definitely want to see this one when you get it restored. Sounds like an ambitious project.
 

KurtinSA

NAWCC Member
Nov 24, 2014
5,734
586
113
San Antonio, TX
Country
Region

roughbarked

Registered User
Dec 2, 2016
8,964
2,133
113
Western NSW or just this side of the black stump.
Country
Region

AndyDWA

Registered User
Dec 26, 2013
621
6
18
Western Australia
Country
Region
Thanks all. It did come with the original dome and is worth at least $10 in parts so I'm okay with it as a purchase - and as a project.

We already have a JUM/7 without that little plastic suspension bracket guard so, if nothing else, we now have one of those :)

Perhaps the most amazing thing about it is that the enamel on the base is in pretty good condition. It's weird to see all the corrosion inside the dome, not outside.
 

Tinker Dwight

Registered User
Oct 11, 2010
13,666
94
0
Calif. USA
It is almost as though someone sprayed something on it.
I once accidentally sprayed white grease on a balance wheel
then I intended to spray brakekleen.
I found out that even brakekleen doesn't remove white grease.
Maybe hair spray or maybe even windex window cleaner.
If you knew a chemist, you might have it analyzed.
Tinker Dwight
 

roughbarked

Registered User
Dec 2, 2016
8,964
2,133
113
Western NSW or just this side of the black stump.
Country
Region
Thanks all. It did come with the original dome and is worth at least $10 in parts so I'm okay with it as a purchase - and as a project.

We already have a JUM/7 without that little plastic suspension bracket guard so, if nothing else, we now have one of those :)

Perhaps the most amazing thing about it is that the enamel on the base is in pretty good condition. It's weird to see all the corrosion inside the dome, not outside.
condensation.
 

MartinM

Registered User
Jun 24, 2011
3,132
129
63
El Dorado, CA
Country
Region
I think this is an example of dezincification:
https://en.wikipedia.org/wiki/Selective_leaching
Probably brought on by the clock sitting on a metal stand in a high humidity area that introduces a galvanic response not only in the dissimilar metals but the alloys, as well.
That. or it was sitting for a long time near a saltwater rheostat or Himalayan salt lamp. :chuckling:
 

Tinker Dwight

Registered User
Oct 11, 2010
13,666
94
0
Calif. USA
It was clearly something that was put on the clock movement.
One wonders if it might have been someone that read one of
R. Feynman's stories about getting a clock to run with soap.
The spots on the drum are from drops of something.
Tinker Dwight
 

AndyDWA

Registered User
Dec 26, 2013
621
6
18
Western Australia
Country
Region
Started dismantling and was going reasonably well until that rusted backplate screw sheared off. I'm not sure how I'll remove the thread without pro tools.

I am unable to separate the plates so far. I think one or two pivots are rusted in place, holding it all together tight.

I'm thinking of soaking the whole movement in a mix of lighter fluid and light oil to see if it will penetrate the tight spots. Or hitting it with doses of WD40.

Since most of the corrosion is to one side, I guess it's possible it was sitting uncovered on a bench while something else was being sprayed with something. Maybe the person realised then covered it, without cleaning it up, then left it covered and wet.
 

roughbarked

Registered User
Dec 2, 2016
8,964
2,133
113
Western NSW or just this side of the black stump.
Country
Region
It might be better to soak it in vinegar before putting things that water
doesn't like.
Tinker Dwight

I agree.

- - - Updated - - -

Started dismantling and was going reasonably well until that rusted backplate screw sheared off. I'm not sure how I'll remove the thread without pro tools.

I am unable to separate the plates so far. I think one or two pivots are rusted in place, holding it all together tight.

I'm thinking of soaking the whole movement in a mix of lighter fluid and light oil to see if it will penetrate the tight spots. Or hitting it with doses of WD40.

Since most of the corrosion is to one side, I guess it's possible it was sitting uncovered on a bench while something else was being sprayed with something. Maybe the person realised then covered it, without cleaning it up, then left it covered and wet.
You only need to penetrate the places that you want to unscrew, for the moment. Don't soak the whole clock in such things.
 

BLKBEARD

NAWCC Member
Nov 15, 2016
759
24
18
CT
sailorsandsettlersantiques.com
Country
Region
Try a piece in a vibratory case polisher. If you don't have one, any friend who is into ammunition reloading will have one. https://www.youtube.com/watch?v=SGeUF1IEhOw

Such as this. It cleans with crushed walnut shells, and is specifically made for brass.
 

AndyDWA

Registered User
Dec 26, 2013
621
6
18
Western Australia
Country
Region
Using intermittent combinations of alcohol and vinegar, I have manged to separate the plates.

Total casualties include: One backplate screw, one dial-collet grub screw and two pivots. :(

At this stage I can only image how I might replace a pivot in a midget escape-wheel arbor so it may be a while before any real progress is made.

The mainspring actually looks to be okay (I am yet to remove it from the barrel), so I think the winding issue may have related to the click not engaging properly.
 

MartinM

Registered User
Jun 24, 2011
3,132
129
63
El Dorado, CA
Country
Region
To deal with the sheared backplate screw, search the Message Board for "Alum". There are a lot of discussions about using a highly concentrated Alum and water solution to dissolve steel from a threaded brass hole.
 

AndyDWA

Registered User
Dec 26, 2013
621
6
18
Western Australia
Country
Region
Interesting. I was going to try and make an "easy-out" but if I can find some alum that might be a less-risky option.
 

Harry Hopkins

NAWCC Member
Nov 16, 2011
558
49
28
Mason, IL
www.harrysclockshop.com
Country
Region
Interesting. I was going to try and make an "easy-out" but if I can find some alum that might be a less-risky option.
I recently used alum to remove a broken pin from a pin pallet anchor. It worked better than my expectations. I mixed it with a heavy concentration of alum in hot water. I would stir it around a few times a day and once in a while I would heat up the concentration again. After a few days I set up the anchor in my mill to drill out the remaining pin and there was nothing left... the drill had no resistance at all. I found the alum with the spices in my grocery store.
 

Attachments

marylander

Registered User
Sep 9, 2008
941
73
28
Maryland
Country
Region
Interesting. I was going to try and make an "easy-out" but if I can find some alum that might be a less-risky option.
Andy, Alum can react with steel but not much with bronze or copper. I used Alum to dissolve broken screws from the front plate. It only discolored my front plate but not taking any off noticeable. I got Alum from my grocery store.
Ming
 

roughbarked

Registered User
Dec 2, 2016
8,964
2,133
113
Western NSW or just this side of the black stump.
Country
Region
Interesting. I was going to try and make an "easy-out" but if I can find some alum that might be a less-risky option.
As with any stuck screw, always look for the least damage method. You may want to get the screw out but you ultimately also want to put a screw back in. Any damage done trying to get it out will only make it stick harder.
 

Forum statistics

Threads
178,855
Messages
1,568,750
Members
54,001
Latest member
Tracy K
Encyclopedia Pages
909
Total wiki contributions
3,078
Last edit
E. Howard & Co. by Steven Thornberry