clock Dial resilvering,

[sparkey0151]

Hi All, just wondered, doing my 1st clock dial renovation and just wondered after applying the silvering powder how long do you leave the powder on the dial before you wash it off, any info on the whole subject would be very appreciated,

thanks in advance john

 

[novicetimekeeper]

you rub the silvering powder with your finger against the prepared brass surface until it is silvered. you need to add enough water to make a loose paste as the water facilitates the ion displacement. You can only displace the copper ions on the surface, so you can't add any more once fully silvered.

edit>

there is a thread here with additional links

https://mb.nawcc.org/showthread.php?139811-tutorial-on-resilvering-brass-dials&p=1084381#post1084381

 

[Sooth]

It's all by feel. My first silvering job looked awful. I did not leave the powder on the dial long enough. Sometimes the silver really applies well, and other times you really need to scrub it in. It's also important that the dial be "grained" and very well cleaned of any oils before starting.

 

[sparkey0151]

Hi i have done quite a few dials since my post with some great success and a few not so good, due to poor preparation, so this is my take on the job, it may help some people out, the best way i found to do the the job was to put some water in a container then put an amount of powder on a plastic type lid, clean the clock dial properly getting rid of all the grime, then i rub the dial down with 400 wet and dry and then some finer grades look at the dial and try to get it looking the same all over as anything on the dial usually shows through, but this is not always avoidable, but you should be able to improve the dials appearance anyway give the dial another clean and thorough rinse, then dip a small paint brush in the water and dab it in your powder and apply to the dial in a circular motion, very soon you should see the dial changing get an even coat all over, i leave it about 15 mins then rinse off properly, then if it looks ok and im happy with the even finish i will go through the same procedure with the neutralizing powder, then dab it dry and use a hair dryer just to make sure, if your not happy with the finish go through the same thing again, its recommended you use de ionized water, thats up to you, this is my take and personal experience, some professionals may chime in and shoot me out the sky who knows, this works great for me, what i can say is dont be scared to have a go, the dial numerals on the dials i have done have been fairly intact but i would not have any probs using engravers wax to re black them there is plenty of info about that on the net, does not look like rocket science to me

 

[novicetimekeeper]

I would not be happy using something as coarse at 400 grit on my chapter rings, it is important to remove as little material as possible as some of the engraving is already very shallow.

I too use plastic bottle lids (I use milk bottle lids) I set those up and have water in another dip my finger in the water and then use the damp finger to pick up the silver chloride. I have never tried a paintbrush, I like to feel what I'm doing and also to make sure I get the silver chloride in contact with the whole surface I press it down and rub it into the brass. keeping it with enough water to make a paste. I use tap water, 300 years ago they would have used well or rainwater, neither is deionised. They made their silver chloride by heating nuggets of silver in brine.

 

[sparkey0151]

Yes i agree i would like you, go for a finer wet and dry type sand paper on reflection, but some of the dials i practiced on were very rough, i tried using 0 wire wool but i was finding it left little shards and had no real affect on the grime, so then went to wet and dry paper, as for a paint brush its just how i started so have just stuck to it after my 1st successful dial, rely dont do many as i have started to become very interested in early carriage clocks and pocket watches, but still clocks, bought a few at auction the other day, got a bit carried away again but once your hooked thats it.

 

[novicetimekeeper]

I'm definitely hooked on longcase, have more than I can fit in already but am still looking at others, might need to move to a bigger house! Horror of horrors I might even have to sell some! (I've already got on out on loan) I'm now trying to concentrate on earlier ones so only really before 1720, and looking for before 1700.

I would keep wirewool away from your dials the rust staining would be a real pain. I clean with a soft brass bristle brush for the dial plates themselves. The plates have been hardened by hammering so the brush is softer than the plastes.

 

[ClipClock]

It's all by feel. My first silvering job looked awful. I did not leave the powder on the dial long enough. Sometimes the silver really applies well, and other times you really need to scrub it in. It's also important that the dial be "grained" and very well cleaned of any oils before starting.

It doesnt actually have to be grained to work, (although aesthetically it might look better). I experimented and polished some scrap brass to the highest shine I could achieve. It silvered perfectly. Agree about the oils though, even touching the cleaned dial with fingers can mar the finish

 

[Nookster]

You guys have any tips to refinish the dials in an off white color? I have a baked enamel dial with black markers and numerals and I want to use the
silver powder with a white finish, as I can't paint the dial as it will coat the numerals and markers.

 

[novicetimekeeper]

Silvering is a chemical reaction where the silver ions replace the copper ions in the surface of the brass. On an enamel dial it would just be a really expensive abrasive powder, like millionaire's scouring powder.

When you say enamel do you mean vitreous enamel or paint? They have different needs and different approaches, I've used saliva to restore old paintings.

 

[Nookster]

The dial is Sterling Silver with baked enamel as the tracks, name and sub seconds track, or what you call vitreous. It's not paint or printed.
There is a color that can be done, I think you guys call it French Silvering. I just want to get that antique white look and not silver. I was wondering if there was a company that sells the correct solutions to do this?

I have the silver powder, but I was told you can add other powders to make it French white, I am trying to find out that combination.

 

[TEACLOCKS]

Watch this guy.

 

[novicetimekeeper]

French silvering is done by using the process above but with fine powdered silver added to the silvering powder.

 

[Frank the Clock]

That's the way teaclocks. That silvering lacquer dries in a few minutes and shrinks down to an incredibly thin layer. I resilvered some 12 inch dials in year 2000 and they still look like new. I had to melt sealing wax into the engraved numerals. What a nightmare the whole face warped badly but on cooling was dead flat again. After I ground the sealing wax flat I washed the face off with water/detergent so bits of black stain would not be drawn out later. I then did as the video and before lacquering washed again. Dried off with an air line and warmed the face up to room temperature before adding a fairly liberal coat of lacquer and once covered don't be tempted to go over the face again. Streaks and fine dust just disappear.

 

[yesyouneedthis]

So were all English brass clock rings silver from 1712 to 1750 ?

 

[Sooth]

It's generally unwise to say yes "all" of them were, because there are always exceptions, but let's say 99.99% were silvered.

 

[novicetimekeeper]

why those dates? Silvering was used on lantern clocks, the first domestic clocks made in England and continued until the end of the brass dial period.

I think the main reason was to improve contrast with the waxed numerals.

Also before the Industrial revolution and the mass burning of coal silver did not tarnish so much.

 

[D.th.munroe]

I'm pretty sure I read somewhere that silvering was used long before clocks, on the reflectors and some decorations of the lanterns lantern clocks were named after.

Also here is another form of silvering for watches with just silver powder, salt and cream of tartar. It's in German but you can get the idea.

 

[novicetimekeeper]

That technique looks like French silvering, where powdered silver is used in the process, though I thought it would be added to silver chloride.

However here you have the basis of the system which is a displacement reaction. The salt makes sure the water has lots of ions, the cream of tartar is a ligand to bind with the copper ions released, the silver is more reactive than the copper so displaces it from the surface of the brass.