An Adventure In Fitting The Wrong Crystal, & My First Time Refinishing A Case

[thor447]

I had previously documented on an earlier thread where I was working on a 1972 Seiko Lord Matic.  Here's a photo if you remember the other thread:

An original faceted crystal was nearly impossible to find, and when I did finally locate the correct part number for sale, it was very expensive.  While doing my research I came across another Seiko part number that by the numbers seemed like it should fit, although none of the documentation I found stated that it was for my particular watch.  The 2nd part number was available for a very reasonable price from Cousins, but unfortunately they did not have a picture of it so I took a gamble and ordered it.  It arrived yesterday, and when I pulled it out of the package I was very pleased to see that it was of the exact same shape and facet profile of the factory crystal in my watch.  When I went to put it on the case I found that was too large to fit in.  Not by much, but just enough that I knew if I tried to force it that it would likely break the new crystal.  The case ID for the crystal measures to 29.8mm.  The new crystal had an OD of 30.1mm.   I knew when I bought it that I was taking a risk, but it was so close I decided to try to see if I could make it fit!  I'm not sure if this is Seiko's Hardlex, or some other form of mineral crystal, but it certainly wasn't an acrylic plastic.  It took a very good amount of time with diamond impregnated sanding sticks and polishing compound, but I began to work my way around the edges of the crystal, taking my time and being very careful that I kept the 90 degree edge on the crystal unchanged.  It ended up taking 45-50 minutes of small sessions of sanding, test fitting, more sanding, more test fitting, etc. until I got the diameter of the crystal from 30.1mm down to 29.84mm.  Once I reached this measurement on my 6th or 7th round of sanding it felt like it would go in.  I got out the press and figured it was now or never!  I'm happy to say that I felt the crystal seat into the bezel, and it went in just perfectly.  It is held securely in place, and thankfully it didn't move around while seating .  I was very nervous about the facets getting shifted and it not being centered after it was pressed in.

Here's a couple of photos showing the modified crystal newly installed in the Lord Matic.  Please ignore the fingerprint covered case.  I didn't take the time to clean it back up before taking the photos.

  

Earlier yesterday while having lunch with a friend of mine who knew that I had been trying my hand at watch repair, he asked me if I'd take a look at a watch he's had in a drawer for a few years that quit running.  He knows basically nothing about watches and just asked me if I could get it running and just clean it up a little bit.  When he gave me the watch it was a small Bulova quartz watch.  It is a pretty interesting looking watch with an incredibly thin case.  I knew that I could help him with it so I agreed to take it back with me.  I'm assuming it's just a battery on the Miyota 9U13 quartz movement so I went ahead and ordered one last night.  After I got my Lord Matic crystal installed yesterday evening I decided to get a little bit of the cleanup done on the watch while I wait for the battery to come in.  I pulled it apart and removed the crystal (which will also be getting replaced as it had quite a large crack in it towards the top - not pictured).  It had what looked to be an integrated bracelet, but they are really just designed to look that way.  The pins to remove the bracelet were very stubborn, so I just decided to clean it as a unit. 

Once cleaned I could really see how beat up it was.  The picture doesn't really tell the full story, but was just covered in scratches and dings.  Since his original request was only to get it running and to clean it, I asked him if he'd be willing to let me attempt to get out a lot of the scratches and try to make this thing look a bit better, aside from just getting it running.  He agreed.  I began with some 800 grit sandpaper, then moved to 1000, 2000, and then some micron sanding papers.  I didn't want to sand too much on a few of the biggest problem areas, but I'd say that I got 95% of the issues resolved.  

 

I ran it on my buffing wheel with some blue and red polishing compound to bring it to enough of a high polish to use a starting point before brushing:

FYI - I did not bother with the back side of the case or bracelet.  They had a brushed finish that was in really good shape and did not need any attention.  All work was done to the edges and forward facing areas.

After about 5 minutes of applying the brushed finish using 3M Very Fine, then 3M Ultra Fine Scotch Brite pads, I'm really pleased with how it came out.  I kept the edges of the case and bracelet polished, and brushed the rest.

I think this watch is going to be stunning when it gets it's new crystal and is reassembled.  Since he's a good friend of mine, we decided that the cost of work would be him covering the cost of any parts, and my lunch!  It turns out I really liked doing the case refinishing work.  It was a learning experience that I really think turned out well.  The lunch was good too, so I suppose it is worth it!

 

Edited September 10, 2022 by thor447

[gbyleveldt]

Wow, nice work on getting that extremely rare crystal to fit and the polishing work on your friend’s watch! I must agree with you, I also really enjoy the case finishing side of things on watches.

I haven’t posted some of my latest projects here - I’ve been lazy.

[thor447]

14 minutes ago, gbyleveldt said:

Wow, nice work on getting that extremely rare crystal to fit and the polishing work on your friend’s watch! I must agree with you, I also really enjoy the case finishing side of things on watches.

I haven’t posted some of my latest projects here - I’ve been lazy.

Thank you!  It is gratifying to get positive feedback from the members on here.  I'm guessing that 99% of everyone on here has more experience than I do at this point, so I appreciate the feedback!