Making a gilt dial (not decal)

[chrome72]

Sold an ebike I made, have lots of play money. I have made some gilt decal dials but want to try to go one step further.

I recently had a 6538 template printed by a UV printer (see image below), it looks a bit grainy though from the preview photo. The printer says its just the way the light it hitting it and it looks very crisp otherwise. My next idea is to coat the brass dial then get it laser engraved, effectively removing the coating and exposing the brass dial. From reading, it appears that the black ink on the gilt dials isn't really ink but a coating (galvanic coating). Any idea what kind of coating went on the old Rolex gilt dials to get the black color?

 

[tripdog]

Any idea what kind of coating went on the old Rolex gilt dials to get the black color?

It's black paint, the gilt is negative relief.

 

[hanski]

I'm not sure I would characterize it as black paint on gilt dials. The dials first used pad printing to mask out the areas intended for negative relief (exposed, polished dial plate) with a special pigment (capable of being "popped" per industry lingo). From there the dial plate is coated using a galvanic process. This results in a black coating. I can't speak to chemical makeup of the bath or how much electricity is used to adhere the coating but it's some combination of something (haha). Afterwards they are baked to release the masking pigment. The dials are subsequently coated with a clear gloss for protection.

 

[chrome72]

I'm not sure I would characterize it as black paint on gilt dials. The dials first used pad printing to mask out the areas intended for negative relief (exposed, polished dial plate) with a special pigment (capable of being "popped" per industry lingo). From there the dial plate is coated using a galvanic process. This results in a black coating. I can't speak to chemical makeup of the bath or how much electricity is used to adhere the coating but it's some combination of something (haha). Afterwards they are baked to release the masking pigment. The dials are subsequently coated with a clear gloss for protection.

Yea that’s what I’m trying to figure out. What the heck was that chemical make up. I wonder if it’s like bluing a gun but black. Any idea what group of minds might be able to replicate a black like that? Like electroplaters?

 

[p0pperini]

hanski Are you describing the modern process specifically, or has this been the process used since the original Sub dials were made?

I'd imagined that the early dials were produced using pad printing in the conventional way - directly transferring ink to the dial surface. As described in simple layman-friendly terms in this article: https://quillandpad.com/2018/11/24/pad-printing-of-watch-dials-explained-reprise/

 

[chrome72]

From what I’ve read it’s a chemical process for the coloring of the dial.

I think a bluing agent would be a good proximity to get a nice dark black
https://www.popularwoodworking.com/woodworking-blogs/use-gun-blue-to-instantly-blacken-hardware/

 

[Hor-Fan]

Graphite

 

[kilowattore]

From what I’ve read it’s a chemical process for the coloring of the dial.

I think a bluing agent would be a good proximity to get a nice dark black
https://www.popularwoodworking.com/woodworking-blogs/use-gun-blue-to-instantly-blacken-hardware/

I know nothing but faded dials turned to brown... I doubt a bluing agent would do the same?

 

[hanski]

hanski Are you describing the modern process specifically, or has this been the process used since the original Sub dials were made?

I'd imagined that the early dials were produced using pad printing in the conventional way - directly transferring ink to the dial surface. As described in simple layman-friendly terms in this article: https://quillandpad.com/2018/11/24/pad-printing-of-watch-dials-explained-reprise/

From what I understand, this is the historic process: https://gmtmaster1675.com/gilt-dials/

 

[p0pperini]

From what I understand, this is the historic process: https://gmtmaster1675.com/gilt-dials/

Thanks for the link hanski - that’s really interesting, and quite unlike my previous vague notion of the process. Every day’s a learning day, even at my grizzled age.

 

[manodeoro]

Yea that’s what I’m trying to figure out. What the heck was that chemical make up. I wonder if it’s like bluing a gun but black. Any idea what group of minds might be able to replicate a black like that? Like electroplaters?

Maybe galvanic plating using ZINC or BLACK OXYD PHOSPHATE ... maybe ...
It seems black oxyd phosphate can turn to brown and flake if not perfectly plated ... just like some negative-gilt dials do ...
Maybe BLACK RODHIUM but the price would be really high ...

 

[chrome72]

Maybe galvanic plating using ZINC or BLACK OXYD PHOSPHATE ... maybe ...
It seems black oxyd phosphate can turn to brown and flake if not perfectly plated ... just like some negative-gilt dials do ...
Maybe BLACK RODHIUM but the price would be really high ...

Yep black oxide is what I was thinking too. Found some product and will purchase it soon.

 

[chrome72]

It seems black oxyd phosphate can turn to brown and flake if not perfectly plated ... just like some negative-gilt dials do .

Doing more reading on black oxide, some gun owners reported their finish having hues of brown after using some black oxide bluing products....

My UV printed dial comes in the mail today. Once I tackle this project I can compare the following:

gilt decal vs UV print dial vs gold foil sticker vs chemical procces/laser etching

 

[chrome72]

Alright, my blueing magic potion (forced black oxide patina) is on its way and lined up a laser engraver. Will post results when I get this work of art done.

 

[jamiex]

Has anyone tried to using a fibre laser to just black mark the negative space? With the power settings high and the speed on low you may get decent results, then just blast it with a couple of coats of lacquer in either matt or gloss and you probably wouldn’t be able to tell whether it’s ink or not.

 

[chrome72]

First attempt at cold bluing the brass, did some experiments on the dial. Polished the dial, taped half of it, other half made a small mark in sharpie to see if bluing would stick there and left the rest of the half blank. Wow, the part that was totally cleaned and clear was a beautiful smooth black as if you were looking into a black hole. I dried it off but it got gummy so I sanded down the dial again and left it bare and let it sit in the black oxide agent. The image below is attempt #2. Not as a rich black as attempt #1, but its a nice color. I need to perfect my technique. I am comparing the black of the brass against my beloved Regimariner and a piece of black electrical tape. More attempts coming in the next few days. If I can replicate the rich black of attempt #1 this is going to be a good way to get a nice black dial which would pair nicely with the polished brass.

 

[chrome72]

After a ton of reading, talking to platers, jewelers and chemist I believe this is the actual process to create the gilt dials:

1- stamp on your design with non conductive ink (I will either get a 3D stamp made or diy an acid etched stamp or diy pad printer)
2-plate the dial in nickel (looks pretty simple)
3-apply a black chromate conversion solution to turn the nickel a deep black color (literally dip the plates dial in the solution for 30-60 seconds)
4-remove non conductive ink revealing polished brass beneath (burn it off or some other chemical means)
5- lacquer the dial up

learning is fun

 

[WatchN3RD]

Just find someone that’s a professional in making circuit boards and silkscreening. Their natural intuition will solve this process ASAP. Wish I knew the answer or a screen printing guy!

 

[p0pperini]

Just find someone that’s a professional in making circuit boards and silkscreening. Their natural intuition will solve this process ASAP. Wish I knew the answer or a screen printing guy!

Possibly a bit late to be recommending that someone else does the legwork on this project, directly below a post by the OP describing in detail every step of the process, painstakingly researched by him.


Sent from my iPad using Tapatalk

 

[manodeoro]

chrome72 ...
100% with you about points 1 to 5
Then white paint and lume ... that's how I proceed on my Doxa dials and it works perfectly ...