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My first sub300t (and my first restoration)

1831 Views 9 Replies 7 Participants Last post by  GabiZ
This is my first Doxa sub300t watch. It's a pre Syncron Sharkhunter, with the sailboat on back. I own it for more than 40 years. I stored it for years after watch fell and the crystal snapped. Seven years ago I decided to restore it . I went for two or three watchmakers for an estimate but In the end I decided to do it on my own. Had to redial/Relume, find a new crystal, gaskets, hands, bezel spring and movement overhaul. Took me a while and finally finished it a few days ago. I'm very pleased to wear it again (though I'm not planning to dive with it)
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Well done 馃憤馃槑
Looks wonderful! I am seriously said you had to replace the hands? Those are so near impossible to find! Or did you repaint and relume them? Either way, dial looks wonderful, as does the rest of the Sub. Glad to see one more vintage Sharkhunter out in the wild!
Thank you. The hands are from yobokies, originally intended for seiko movement. The vintage doxa movement uses the same hands size as the seiko.
Here are some more details about this restoration:

The original watch looked like this:

As you can see there was a lot on my list:
  • There were scratches on the dial and the black lost its depth, The lume was in bad shape (though the lettering was better.)
  • The hands were missing, and I had to find something that resembles the original hands ("Hens teeth")
  • The Mineral Crystal broke long ago and I had to find crystal and gasket(s)
  • The rotating bezel had to be polished painted.
  • The bezel click spring was missing.
  • The crown gasket over the years became black goo and had to be replaced.
  • The crown tube gasket was missing (I didn't know it at this point)
  • The movement was in fair shape, but has to be serviced.
I decided to do it all by my own after I received several estimates from watchmakers (I guess this was my intention from the beginning but I didn't have the know how nor the confidence.) Took this as a project and had to dig for information. Since it's a very specific version of the sub I had to find the right info. If I compare it to Geoff's restoration there are some similarities but lots of differences: Crystal, gaskets, crown movements are all different.

I sent the face to Robert Miller at international dial company. He told me he has the original dies for the professional sub (The orange) for this watch he had to change it to sharkhunter.
(this was seven years ago, now I see the company changed its location and website)
You can compare the before and after.

The Hands

As the original hands were lost, and there are no originals to be found.I Found very similar ones at Yobokies. This sub uses Eta 2472 movement (aka doxa 118), which uses the same hand size as seiko. Yobokies (and dagaz) sells seiko mods, and the "soxa" hands looks very similar to the sub's hands. Since they were meant for slightly bigger dial, I had to shorten the seconds hand. I was also happy to see that the lume color on the dial and hand were the same.

The crystal and the crystal gaskets.
Since the crystal broke years ago I had to find one that fits. I was a little bit confused from what I saw on the net until I realized there are few versions of the sub. In the synchron sub for example the crystal is a thick flat mineral glass. It is inserted from the front and held by a thick visible orange gasket. In this version the the crystal is a stepped glass, 3.6mm thick approx, it is inserted from the back of the watch and held by a screw in retainer ring, with no visible gasket.
Because it is not manufactured anymore, some watchmakers produces a close clone by bonding two flat crystals in different thickness and size. This guy on the bay produces this crystal by copying an original one(as he said). He posted it as a "DOXA SUB 300T Sharkhunter" crystal unaware of the various possible versions for this title. At the time I wasn't sure it will fit mine, so I made one using the watchmakes method by bonding two crystals to one using ultraviolet curing bond.
At the same time I was looking for a fit gasket when I stumbled on a post in this forum by David "Granitequarry". Now You can't see the original post's images, but in this image (from the post) I found that the Crystal was held by two (probably the same) gaskets (the gaskets on the center of the image).

I ordered some gaskets in various possible sizes and choose what fitted best. The gaskets fits the inside of the watch and around the wider bottom side of the crystal. It is all held by a screw-in retainer ring.

The rotating bezel
At the time I didn't notice the bezel has polished and brushed parts, so I polished it all, and colored the marks and numbers using nail polish lacquer. On the luminous dot I used epoxy glue mixed with luminous powder. It was one of the first things I did on the watch and left it as is.

The bezel spring
Had to create a new bezel spring following this post. I used dentist's 0.8mm stainless steel wire but I wasn't sure what of the exact wire girth, so I ordered from AliExpress various wire sizes.
Made this spring. It's not perfect but its doing the job.

The crown gaskets
The original crown gasket became black goo long ago. Couldn't find any information regarding this screw down crown. The closest design I found was Rolex twinlock crown . From the shape of the crown and tube I assumed the possible sizes of both case and crown gaskets. I ordered some possible gaskets sizes and used the ones that fitted best. I added even one more gasket around the case tube to imitate the Rolex triplock (obviously unnecessary...)

The Movement
In this watch doxa used the Doxa 118 movement - a slightly modified eta 2472 movement. The movement had to be serviced. On some point on this long period I decided to service it on my own. It was the most intimidating part of this restoration because I had to learn this from zero.
Bought some old movements on the bay for cheap, bought some required tools and started to take them apart and rebuilt them again. After I gained some confidence I did it on the doxa. I made some damage but found the right replacement parts (One of my discoveries was that movement springs tend to fly and disappear while flying…). It took me longer than I thought. For couple of years I left it in the box, but the covid19 period gave me little time to get back to it and finish the job.


more to do

Need to regulate the watch, probably after I will build a proper timegrapher mic.
Maybe pressure test: just to check how waterproof is it. I'm not planning to dive with it.
Bor bracelet: maybe yobokies. found this on alibaba but minimum order is 200…



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