Seiko 7A38 - by the numbers



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Forum Home > Parts Info, Tech Tips and Tinkering > Cleaning and lubricating bands

Rob Benham
Posts: 281

If the band is cleaned by total immersion, it's inevitable it will be 'running dry' when air dried.  I had no product to do my old watch, so used WD40 which worked well in terms of cleaning.  I dried it with 100 psi in the garage, and can feel no residue on my wrist.  The 'new' project has been cleaned in spirit, and dried in the same manner.  The difference in feel is chalk and cheese. 

I can only assume there is a difference in the wear, but the oilyness of WD40 I'm sure is playing a part in the snake-like silkyness of the first one.  What do the experts do to lube the links and indeed the pins?

December 27, 2013 at 4:07 PM Flag Quote & Reply

Sir Alan
Posts: 458

All I've ever done is clean my bracelets using an ultrasonic bath and an ultrasonic toothbrush, then dried them off.

I've never lubricated them, I think that this might attract dust, dirt and DNA.

I cleaned up a 30yr old bracelet today. Even after several 4 minute bouts in the ultrasonic bath and then vigourous brushing there was still loads of crud under the removeable links:

so. these were all taken apart and had another clean.

December 27, 2013 at 4:46 PM Flag Quote & Reply

Rob Benham
Posts: 281

Oh, that's a thought.  I didn't open them this time.  Wonder what I'm going to find.

December 27, 2013 at 5:54 PM Flag Quote & Reply

Site Owner
Posts: 14136


The only time I've ever used WD40 on a watch bracelet was on a Seiko p/n B1241S on a 7A38-7070 which had suffered from minor salt water damage. The links in that bracelet are joined by what are best described as miniature hinges. There was some rust-staining on a couple of hinges and one pin was seized solid. The bracelets you are referring to are the B1170's on your 7A38-7000's, which are normal (flimsy) folded link construction - as shown in Simon's photo. There is absolutely no need for lubrication.

However, unless you want to risk catching some skin disease from a previous owner, cleanliness is paramount. Like Simon, I use an ultrasonic cleaning tank. You can buy them reasonably cheaply from Maplins; Aldi, Lidl, etc. My personal tweak (which saves on the number of sessions in the ultrasonic tank) is to leave any extremely dirty bracelets soaking in neat Flash cleaning solution overnight.

I will also give them a swill under the hot tap and a brushing with an old toothbrush in between ultrasonic sessions.

The only downside of a thorough cleaning is that you may make what was already a well-worn bracelet even sloppier.

Prime example here:

In the meantime, having soaked overnight in neat 'Flash' cleaning fluid, followed by three 10 minute cycles in the ultrasonic tank, the bracelet had since been relieved of two and a half decades worth of solidified 'wrist cheese' and all evidence of the owner's DNA. 


I knew it was badly stretched before I started cleaning out all the muck from between the links, but now actually being able to see how badly the small interconnecting link sections are worn, I'm beginning to wonder about the wisdom of fitting a new (secondhand) clasp.

If I do, I think the next thing to break (soon after) will be the bracelet itself. Anybody got a spare p/n Z1093C bracelet going cheap ?

December 28, 2013 at 7:42 AM Flag Quote & Reply

Rob Benham
Posts: 281

I was looking at my original watch's band a moment ago, and wondered about the ratio between pressed close and stretched. There are the same number of links in my gold plated 7A38-7000 so I'll make a comparison when time permits.  I feel the substantial increase in length is not a good sign.  :(

My vernier won't reach but a tape shows a change of very roughly 190:178mm

December 28, 2013 at 7:00 PM Flag Quote & Reply

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