1970s Seiko cases

[Levine98]

So I picked up a mid-1970s Seiko 7006-8007 to learn about vintage Seiko movements. The movement is working but poorly (perfect for learning how to service), but the case is really worn.

i know all of the bulovas I’ve worked on were either SS or 10k RGP over brass. Does anyone know what process Seiko used for their entry- and mid-level watch cases? I don’t want to put a lot of time in trying to clean up the case until I know what’s underneath the worn plating.

thanks

[watchweasol]

Hi iwould remove the movement and clean it up with mild soap and water to remove surface grime, if the plating is bad a donor case from the likes of welwynwatchparts.co.k. Or speedtimerkollection.com in Europe  sellers f cases and second user parts

[xyzzy]

Seiko has a code on the case back that should say what the case is made from.  It should be somewhat self explanatory.

It's probably stainless, with gold plating.  It's not RGP or gold filled.  You can't polish the gold more than the slightest amount without wearing through it.  Which looks to have already happened on the lugs and sides anyway.

It could be "base metal" under the plating too.  If you see any pitting then it's probably that.  But that looks worn enough that were it base metal, it would be pitted, and it doesn't look that way in the picture, so I'm guessing stainless.

If it's stainless, you could convert it to a brushed finish.  If it's base metal, I don't think there is really anything one can do.

[rossjackson01]

13 hours ago, Levine98 said:

So I picked up a mid-1970s Seiko 7006-8007 to learn about vintage Seiko movements. 
thanks

 

Levine98

Would be really interested in your repair of the movement. I've spent most of my learning on Seiko models 6309, 6319, 7009 and 7S26. I can always get them repaired. Running well. However I can rarely get the Amplitude above 150+. Let me know your result please. 

Ross 

[mikepilk]

1 hour ago, xyzzy said:

It's probably stainless, with gold plating.  It's not RGP or gold filled.  You can't polish the gold more than the slightest amount without wearing through it.  Which looks to have already happened on the lugs and sides anyway.

Can you gold plate on top of stainless steel?  If the plating is badly worn, you could replate (expensive), just polish it, or if the base is SS, polish it back to a SS finish.

 

[Levine98]

Mystery solved. Case is base metal (brass) and the bezel is SS. I ended up taking the plating off last night and both the case and bezel had a layer of nickel underneath the gold plate (which is extremely thin indeed). This info is on the case back as well as noted above—just didn’t see it until I cleaned and polished the case back. 

I’m going to just re-plate in nickel since I have the stuff on hand—not going to invest in gold plating solution for this watch since i doubt I can even recover the cost of purchase at this point re: needs a new crystal and mainspring (which I broke while trying to reinstall with my antique mainspring winder—May be time to invest in bergeon like winders).

3 hours ago, mikepilk said:

Can you gold plate on top of stainless steel?  If the plating is badly worn, you could replate (expensive), just polish it, or if the base is SS, polish it back to a SS finish.

 

I think you have to put on a thin layer of nickel first.

3 hours ago, rossjackson01 said:

Levine98

Would be really interested in your repair of the movement. I've spent most of my learning on Seiko models 6309, 6319, 7009 and 7S26. I can always get them repaired. Running well. However I can rarely get the Amplitude above 150+. Let me know your result please. 

Ross 

I’ll let you know once I get a replacement mainspring  if you have any extras laying around you’d like to sell let me know (7009 and 7S26 are same).

Edited April 21, 2023 by Levine98

[Waggy]

5 hours ago, mikepilk said:

Can you gold plate on top of stainless steel? 

You have to plate with an intermediary metal first like nickel - but I like your idea of taking all back to stainless steel.

[xyzzy]

My understanding is that gold plating usually has a nickel strike layer applied first.

"SGP" on the back means gold plated base metal.  If it's stainless steel it'll just say "St. Steel" and not indicate plating or not.

I think unplated brass will tarnish quickly and pit from sweat.

[Levine98]

On 4/21/2023 at 3:36 AM, rossjackson01 said:

Levine98

Would be really interested in your repair of the movement. I've spent most of my learning on Seiko models 6309, 6319, 7009 and 7S26. I can always get them repaired. Running well. However I can rarely get the Amplitude above 150+. Let me know your result please. 

Ross 

Just finished one of two Seiko 7006s. To you question here is the result of the first one.

Crown up/down is closer to 200 as you’d expect.

Edited April 27, 2023 by Levine98

[rossjackson01]

44 minutes ago, Levine98 said:

Just finished one of two Seiko 7006s. To you question here is the result of the first one.

Crown up/down is closer to 200 as you’d expect.

 

Aaaagh!

[Levine98]

1 hour ago, Levine98 said:

Just finished one of two Seiko 7006s. To you question here is the result of the first one.

 

 

52 minutes ago, rossjackson01 said:

Aaaagh!

Haha, didn’t mean to rub it in  are you winding the mainspring as full as possible when you measure the amp?

[rossjackson01]

56 minutes ago, Levine98 said:

 

Haha, didn’t mean to rub it in  are you winding the mainspring as full as possible when you measure the amp?

Yes. I'm going to o a disassemble my movements and begin again. Need to overcome my problem.

[Levine98]

On 4/27/2023 at 12:32 PM, rossjackson01 said:

Yes. I'm going to o a disassemble my movements and begin again. Need to overcome my problem.

So I feel your pain re: while I got the watch back together and running, I noticed it wasn’t auto-winding very well (leading to only running about 12 hours at a time). So I took it completely apart, recleaned everything, and took my time applying lubricants.  One thing I did different this time is fully disassemble the magic fingers mechanism (wheel, etc), and more thoughtfully clean it and lub it. 
 

So now it appears to auto-wind more freely, but I can’t get the amplitude above 180 dial up or down.
 

not sure I like these seikos…..