Mineral glass for Sapphire swap on Solar charged movements

[WatchingOracle]

Hi Everyone. Hope you are all well.

So the Citizen I have (E100-K18434 CK) is in need of a new crystal. Old one is scratched and chipped. Seems the last owned did a number on it lol.

OEM for this Citizen is for flat mineral glass, but given this is a Titanium Citizen I was thinking I should upgrade the crystal to a domed sapphire when ordering a generic crystal for replacement.

Are there any issues with solar movements (Citizen Eco-drive E-100 calibre this one is specifically) and swapping out mineral for sapphire with regards to the difference in refractivity, reflectivity and the light and and bearing it may have on the solar charging component of the watch? Any other issues doing a swap like this? I know that a lot of the latest Titanium CItizen's have sapphire on their Eco-drive calibres but thought I should ask especially given I have never done a swap (or a crystal change) before so...yeah haha.

Cheers!

[oldhippy]

I would replace it with the same type that it had when it was new. 

[jdm]

4 hours ago, WatchingOracle said:

Are there any issues with solar movements (Citizen Eco-drive E-100 calibre this one is specifically) and swapping out mineral for sapphire with regards to the difference in refractivity, reflectivity and the light and and bearing it may have on the solar charging component of the watch?

Really I don't think there is any. The efficiency of these is very high, a brief exposition is enough to get a solar watch running for a long time.

[KOwatch]

Often tricky part of a mineral-sapphire swap is that while mineral crystal sizes increase by .1mm, sapphire replacement crystals are usually only available in .5mm size increments.

[LittleWatchShop]

Looks like a pretty wide bandwidth...I think you will be fine.

[WatchingOracle]

@oldhippy@jdm@KOwatch@LittleWatchShop Thank you all for the input and advice. I need to see what size I need. The issue with Citizen is that they seem certainly fussy about keeping parts of their watches underwraps when it comes to information. I know from the service guide I found for the watch, it doesn't list a thing about case or crystal components at all lol! I guess as I suspected whatever I get will be a generic crystal and given what KOwatch said with crystal sizes, I would need to see if a sapphire would be even possible as an option.

I guess at the end of the day it needs a new crystal as the chips in this are bad. I just got to see what works and I guess need to consider if my 'wants' are feasible. Cheers guys for all the advice

[LittleWatchShop]

I have replaced four glass crystals since I started this hobby.  Every time, I struggle with the exact sizing.  So, I buy several sizes on either side of the nominal measurement.  This is cheap insurance when replacing mineral glass.  However, If you are replacing with sapphire, then the economics of that idea kinda tank!

Here is an idea to consider.  Buy a replacement mineral glass of the size that you measure.  If it fits, you can either 1) wear it as is, or 2) pop it out and buy a sapphire glass of the same dimensions.  If you like option 2, then just buy a cheap flat mineral glass because it is cheaper than domed.  For the cheapest, buy 1mm thickness.

The experts on this forum have most likely developed a sixth sense about sizing these things.  I am sure that once you do hundreds, you can get it right every time.

[jdm]

7 hours ago, WatchingOracle said:

The issue with Citizen is that they seem certainly fussy about keeping parts of their watches underwraps when it comes to information. I know from the service guide I found for the watch, it doesn't list a thing about case or crystal components at all lol!

Citizen is not ever the worst of the Japanese makers when it comes to documentation or making parts available, that award goes to Orient. In the end they are makers of low/middle priced watches sold to the masses with the expectations that whe  it breaks either a new one will be bought, or sent to the official service center, just to be told that after 5 years parts are not available anymore - actually I doubt that except the most common ones, parts  are ever available.

At some point we had a USA based member that every time a Seiko or Citizen part issue was mentioned, would jump in and write, "no problem - computer says that part xx-zzz is orderable from the manufacturer". It took a bit of dialogue to have him admit that he was a just a jeweler with accounts with both makers, and was accessing databases not available to the general public, much less the part itself was available of course! This exercise must have fatigued him, as after a while he disappeared from our screens.

All that being said, once you measure it you will find that with 99% chances the crystal is flat (please post pictures next time), sized in increment of 0.5mm, and can be replaced with sapphire without issue if so you desire.

 

[WatchingOracle]

4 hours ago, jdm said:

Citizen is not ever the worst of the Japanese makers when it comes to documentation or making parts available, that award goes to Orient. In the end they are makers of low/middle priced watches sold to the masses with the expectations that it breaks either one will be bought, or send to the officiale service center, just to be told that after 5 years parts are not available anymore - actually I doubt that except the most common ones, parts  were ever available.

At some point we had a USA based member that every time a Seiko or Citizen part issue was mentioned, would jump in and write, no problem - part xx-zzz is "orderable" from the manufacturer. It took a bit of dialogue to have him admit that he was a jeweler with accounts with both makers, and was accessing databases not available to the general public, much less the part itself was available of course! This exercise must have fatigued him, as after a while he disappeared from our screens.

All that being said, once you measure it you will find that with 99% chances the crystal is flat (please post pictures next time), sized in increment of 0.5mm, and can replaced with sapphire without issue if so you desire.

 

@jdm Oh that is all very interesting!!

Yes I do know what you mean regarding the watches being considered by some companies as being 'throw away'. I am not a fan of Citizen watches generally from poor experiences with their products as a young teen and having received one or two as presents. Citzens were common cheap gifts back then here especially their lower end stuff it seemed -though I avoid them like the plague.

The only reason I acquired this watch was it was dirt cheap for a titanium and primarily I wanted to see what it was like to work/restore a finish on a beat up/damaged titanium case and band whilst I wait for my watch repair tools to arrive in the mail in the interim.

I do plan on posting images but right now I can't even get the crystal out as I don't have my press yet! So all talk of replacing the crystal is still theoretical until I can measure the thing out of the case. You are right the present crystal is flat but this thing to me is screaming to me for a bit of curvature if I can as flat on this model to me, just doesn't look right (maybe I am too used to domed retro Seikos lol)

I will probably make a separate post about this watch as time continues as it will be about the titanium restoration first. Though a mild snag there is - that it seems rotary tools give a better finish and I need some new rotary heads to arrive in the mail after my hand finishing thus far is (whilst an improvement on the original finish) sub-par to my standards lol.

[jdm]

59 minutes ago, WatchingOracle said:

I wanted to see what it was like to work/restore a finish on a beat up/damaged titanium case and band

Titanium is friendly and rewarding to restore. You can buff out scratches and dings easily, but be very careful when using a rotary tool, because you could dig valleys without even realizing. A nice brushed finish is in everybody's reach, stroking a green pad always in the same exact direction.

 

59 minutes ago, WatchingOracle said:

for a bit of curvature if I can

Flat bottom, low dome crystals are very popular among modders, and easily found on Ebay, AliX, etc.

[WatchingOracle]

12 hours ago, jdm said:

Titanium is friendly and rewarding to restore. You can buff out scratches and dings easily, but be very careful when using a rotary tool, because you could dig valleys without even realizing. A nice brushed finish is in everybody's reach, stroking a green pad always in the same exact direction.

 

Flat bottom, low dome crystals are very popular among modders, and easily found on Ebay, AliX, etc.

Yes I agree, this thing was very badly dinged and scratched up, the inner bracelet was mirror finish and the outer satin portion a brushed finish. I was able to restore the outer satin finish fine but that mirror finish requires the stuff i've ordered as the shape of the links (these ones don't have the ability the removed for the 2/3 of the bracelet) is difficult and curved and research online seems to show gentle rotary would be the best to get those potions mirror shine again. I will post with how it all goes.

A flat bottom low dome is exactly the type I am hoping for with this so fingers crossed I can find something in this profile I am happy with

[WatchingOracle]

Hi everyone.

Well I thought i'd update this post. I successfully got the mineral glass watch crystal out... Though depends on how you gauge success lol. The glass shattered when I used the press.

I was doing it carefully, following the course video instructions. I guess I half suspected it might shatter given a) i've never done this before b) the state the crystal was in prior. When it made the 'pop' I was listening out for, it had popped loose I thought... but realised the glass instead shattered into 100 pieces, and the 'popping' was the glass breaking in the centre of the press.

Not ideal I know.

I used a piece of masking tape and carefully applied it and was able to hold the silhouette of the shape more or less to get some measurements from and then also took some of the case.

With the calipers I got 27.5mm for the diameter of the broken glass silhouette. Measuring the internals of the case across ledge to ledge was 27.3mm. Thickness I gauged from the largest fragment, as best I could which was 1.3mm.

I think the glass in this case had actual adhesive applied to hold it in place...which I guess would explain in addition to the glass already having chips and hairline fractures in it why it totally shattered how it did. Looking at it before I tried to removed the crystal, I wasn't sure what kind of fit the glass was. I couldn't make out any kind of gasket or tension ring and thought it might have been press-fit but it wouldn't budge when I tried. Under the microscope its clearly got some kind of off white coating on the interior wall of the case ledge that must be the old adhesive.

I guess acetate to get that off before I try to put the replacement in?

I'm honestly surprised this watch had a glued in glass. I expected more from Citizen for their Titanium watches especially as this thing is mid 90s (I think) and they were still a premium line product back then weren't they??.

My big question for those of you playing along at home (lol) is that when it comes to the replacement then, does this new information change things in regards to my wanting to replace this still with a sapphire watch crystal? Would I be gluing whichever replacement I choose, like the old one was (in which case what is the best glue to use?) or should I go for a different type of fitting glass? Again noob questions from this noob so I apologise in advance.

 

[LittleWatchShop]

I just replaced a mineral crystal in a Citizen yesterday.  It was glued in.

When I removed it, I used my BB crystal press and a 3D printed top press piece that perfectly fit to the edge of the crystal.  Once the press was seated properly, I gave it one quick press and I got the crystal out in one piece. Maybe I got lucky...dunno.

I glued the replacement in with G&S Hypo cement which I believe is the glue that experts on this forum recommend.  Were it me, I would proceed with your sapphire plan. 

As far as fitting, I would measure the inside diameter a dozen times, resetting my caliper each time, just to make sure.  Not sure I would trust humpty dumpty measurement.  Regarding thickness, I have not seen 1.3mm thickness option in mineral or sapphire.  Had a discussion with @jdmabout this and he offered good insight regarding the personal choice of "proud" crystals where the crystal rises above the bezel. I am pretty sure that is what you would want to do here--replace with a 1.5mm.

Edited September 13, 2021 by LittleWatchShop

[watchweasol]

A soft way to remove glued in crystals is a soak in warm water they usually pop out no problem.  If it was glued in before then do the same using either G&S cement as recommended or Ultra violet cement as supplied by Sternkruz both good for the job.

[WatchingOracle]

@LittleWatchShop@watchweasol Thanks so much for the feedback!

I measured the interior ledge to ledge a dozen times easily. It kept given me some variance and I think the glue was responsible for that. I plan on taking the glue residue off over the next day or so and doing interior measurements again.

The fact that it had 27.5 on the glass surprised me given the 5 or 6 times I took that from where it was most intact - held tight with the calipers given the measurement was the .5 makes me think that it might be correct. I remember seeing a video somewhere saying that there can be a difference however between a glass measured vs interior case ledge to ledge...need to find it again. Especially given the broken glass variable. I guess I could do what Mark suggests in the video on glass replacement tutorial, if in doubt buy a few around the measurement size.

@LittleWatchShop Ok so another watch with a glued in Citizen crystal. Interesting. I will admit, that the glass breaking did 'get' to me a bit right after it happened. It had left me feeling unnerved a bit. I am telling myself that it was a bit of pure bad luck that my first ever attempt removing a crystal was a glued in one and not the different type! If its glued in and the glue is good, then it shattering is the only outcome expected then (unless you do the soaking/removal first I guess)?

I plan on doing a 'proud' fit for this, as you mention, with a low dome if I can as I think it honestly would finish off the appearance of this watch better. 1.5 would sound ok to me. Flat top never looked right on this thing from the moment I saw it in the pictures!

@LittleWatchShop@watchweasol I need to see if my supplier has the G&S cement. I have heard you can use clear 2 part epoxy (I actually have a very good one from Selleys that is a 'crystal clear glass finish waterproof with extra high tensile strength' I have used on jewellery repair on a bracelet with amber and with types of natural quartz crystals for rings and the like. But I don't know if I am game to try and mix things up THAT much with this repair lol!

 

 

[jdm]

46 minutes ago, WatchingOracle said:

Measuring the internals of the case across ledge to ledge was 27.3mm. 

Then you need a 27.3mm crystal. No press must be used for glued crystals. 

[WatchingOracle]

Just now, jdm said:

 No must be used for glued crystals. 

??? Confused mate. Could you please rephrase.

[jdm]

2 minutes ago, WatchingOracle said:

??? Confused mate. Could you please rephrase.

Corrected above. 

[WatchingOracle]

@jdm Cheers. Yeah I won't make that mistake again lol.

 

@jdm@LittleWatchShop@watchweasolI had a look at my supplier. Looks like they have the G&S hypo. Is the stuff good then? They also have a Seiko glue that they list as recommended though that's UV curable.

Is the 'glue' question the same as the 'oil' question in regards to it being a can-of-worms and that everyone has an opinion??

 

 

[LittleWatchShop]

13 minutes ago, WatchingOracle said:

G&S hypo.

G&S has been around forever.  I have a tube that is probably 35years old (but I recently I bought a new one). It was my Dad's go to glue--back then they did not have the UV stuff.

[watchweasol]

I am afraid there are many opinions , likewise lubrication as the recipient of all this advice you have to sift thro it all and decide which is best for you. That is the nature of forums. when fitting a crystal with glue sufficient covering within the rim, no excess press in the crystal by hand and rotate sightly to ensure a good bed, then leave to dry or go under the UV lamp. I have done a few and had no problems using the sternkreuze UV cement.

 

[WatchingOracle]

@LittleWatchShop@watchweasolCheers guys again for that latest feedback.

Ended up ordering the G&S hypo. The Seiko crystal glue I was told is UV curable and will only bond glass to metal, unlike the G & S that will work on a heck of a lot of wider variety of substances. Only downside of the G&S is the fumes having the ethylbenzene in it, so its an outdoor or fume cupboard glue only.

I couldn't get the sapphire from the local supplier in the right size for the case and I didn't like the one type he had that would have fit. Rather than play parcel roulette getting it from elsewhere, I decided to instead get a domed optical magnification mineral glass from them instead this time around. The smaller diameter of the dial face I think will look nicer that bit larger on magnification and the domed surface of the crystal lens will still have that aesthetic I wanted still, instead of being flat. For the price if I don't like it, its only a $3 bucks and I can always swap it out later.

I can focus on what to do with the case titanium finishing now if I can get my hands on some finer grit papers for my rotary tool Crazy what stuff has shortages right now. Who knew sandpaper could be such a hot commodity. 

[jdm]

13 hours ago, WatchingOracle said:

Ended up ordering the G&S hypo.

For many watches, where full originality is not important, a practical alternative is to fit a nylon gasket, usually available from the same crystal suppliers.

 

13 hours ago, WatchingOracle said:

Only downside of the G&S is the fumes having the ethylbenzene in it, so its an outdoor or fume cupboard glue only.

I can tell you for sure that the "fumes" from GS cement, in normal use with a closed room wouldn't hurt a  squirrel, let alone an human.

[LittleWatchShop]

7 hours ago, WatchingOracle said:

Crazy what stuff has shortages right now. Who knew sandpaper could be such a hot commodity. 

Supply chain is just nuts.

[WatchingOracle]

On 9/14/2021 at 8:27 PM, jdm said:

For many watches, where full originality is not important, a practical alternative is to fit a nylon gasket, usually available from the same crystal suppliers.

I was wondering about that and how that would go with watch modifications to crystals. What would one expect to see for a 'typical' water resistance like with that kind of modification? I know it would have quite a bit of variability and that my question was a loaded one, but I guess would it at least be what the glued in original was assuming there is a good seal?

Thanks for answering that unstated question I had!

On 9/15/2021 at 12:07 AM, LittleWatchShop said:

Supply chain is just nuts.

Yeah the local supplier said to me when putting the order through on Friday that it has taken them 6 solid months to get anything made by Elma shipped to Australia for instance! They have had such a backorder apparently you wouldn't believe. I feel lucky I was able to get my Elma Red cleaning concentrate in that order.