How would you clean without damage?

[pkamargo]

The picture shows the back plate from a table clock. It has some ‘decoration’ on the surface that is very superficial.
The bottom of the plate is getting tarnished… I would like to have it shiny again but any brass polishing method would erase the decoration.
So, how would you proceed?

[chris mabbott]

There are a few methods that will clean but won’t leave the finish shiny as you desire, whereas they will remove most of the surface discoloration, what you will be left with is a dark, dull finish.
Unfortunately, only polishing, which removes a certain amount of material in the process, can give you that new, shiny look.

If you are careful and use soft cotton cloths, possibly a mild, fine brass polish with minimal force, you will retain some of the decorative machine work.

The same holds true for inner, outer plates on pocket watches where a fish scale design has been applied, this is also easily removed with too much force. I use a polish applied by hand to restore the luster, which works fine for me.
Although it took practice..

Try various methods on the inside plate and see how it looks and feels. When you’re comfortable, move on to the decorative side, but gently..

Keep in mind that the tarnish is also acting as a highlighter, once you remove the darkened areas, the design will not be so standoutish.

[bernie weishapl]

Chris is absolutely right. If you are careful you can clean and shine the plate. You will not get rid of it all. I saw a old gentleman that used ammonia and dawn dishwashing soap to clean his plate. They were nice and shiney when he was done but the problem I see with that is it will also lift the lacquer off. Then you will have to make sure it is clean to make sure all the old lacquer is off and then relacquer the plates. In order to do this You will have to put toothpicks in every hole then spray the plate using several very light coats. It is a art within itself. Then after the one side is dried turn it over and put your toothpicks in the holes on the other side and spray. You don’t want to get any laquer in the pivot holes thus the toothpicks. I have only re-laquered one plate and it is a long process. So you must be patience.

[cazclocker]

I might be missing something, but what about just soaking the plate in a non-ammoniated clock cleaning solution that contains oleic acid? Oleic acid has good brass-brightening properties. It seems to me that a solution like that (I use Historic Timekeepers solution) would do the trick without scrubbing, with or without an ultrasonic.
Just my thoughts…
…Doug in Arizona

[arutha]

soaking the plate in a clock cleaning solution would bring the plates up but only if it removes the lacquer first. Nothing can clean the brass under the lacquer. As Bernie has already stated, re-lacquering is quite a process. You could just soak off the lacquer and brighten the brass but without a new coat of lacquer it will go dull again.
Paul.

[pkamargo]

Hello all, and thank you for your replies.

-Chris, when you say try some methods in the inside plate – the point is that I will not be able to evaluate how any of them would affect (or not) the decoration. Testing any rubbing method would only be valid on an equally decorated surface. But you made me remember of a polishing product that can brighten even without rubbing, just for the contact with the product. Not sure if it will keep the shine… Maybe it will worth a try.

-Bernie – “I saw a old gentleman that used ammonia and dawn dishwashing soap to clean his plate.” Google tells me that dawn is a brand name, but I don’t have this product here in Brazil… I could try any other dishwashing soap but I would need to know exactly how much ammonia to add. Anyway, relacquering the plate is always required after a polishing process. Sometimes I do it using a paintbrush, sometimes using airbrush. I don’t care putting toothpicks in the holes because I know I can clean them after easily.

-Doug, non-ammoniated clock cleaning solution would be a good try, but I would have to order it overseas, it’s not avaiable here. But I did a fast google search about oleic acid and this is not hard to find. I will make some testing with this acid to check its brass-brightening properties!

Well, now I have something to start testing and trying. Will let you know the results.

[cazclocker]

@Arutha wrote:

soaking the plate in a clock cleaning solution would bring the plates up but only if it removes the lacquer first. Nothing can clean the brass under the lacquer. As Bernie has already stated, re-lacquering is quite a process. You could just soak off the lacquer and brighten the brass but without a new coat of lacquer it will go dull again.
Paul.

Paul, I re-read the original post and nowhere does he state that the plate is lacquered. He says it has a “decoration” on it – which I believe was his word for the rather odd attempt at a damasceening-like effect on the plate’s surface. I didn’t see any indication that it was lacquered.
…Doug

[arutha]

@cazclocker wrote:

Paul, I re-read the original post and nowhere does he state that the plate is lacquered. He says it has a “decoration” on it – which I believe was his word for the rather odd attempt at a damasceening-like effect on the plate’s surface. I didn’t see any indication that it was lacquered.
…Doug

Hi Doug,
I may be mistaken but certainly this side of the pond I have yet to see plates that have damaskeening of any kind that have not then be lacquered. In wanting to keep an original finish i would first make sure they are not lacquered before bathing in cleaning solutions which could remove any lacquer.I don’t know how much experience pkamargo has with lacquered clock plates and also as these posts are often read by beginners I feel it is always best to er on the side of caution.
Paul.

[pkamargo]

People, the plate IS lacquered. The areas that got tarnished had lost the lacquer – I believe because of excess of lubrication that was on these areas and that I cleaned before taking the picture. Under all the remaining lacquer the brass is not tarnished.

So, that I called decoration you call ‘damaskeening’? I would never guess this name!

[pkamargo]

OK, so I first tryed the polishing paste without rubbing. Cleared a little the tarnish, but not enough.

Then I tryed something that is supposed to be around 80% oleic acid – olive oil. No effect at all.

Third test, something that I always use to brighten clock chains: vinegar. And yes, it worked. Just soaking and softly rubbing my finger tips for a minute to get all tarnish gone. Then I made a little mistake: used paper towel to wipe and dry. The paper was not soft enough and made the bottom of the plate a little dimmish. Should have rinsed with water and heat dryed.
Then I soaked in a solvent to remove the original lacquer, dryed carefully… 🙄 And re-lacquered.

Picture below show the result. I’ll not say “What a PERFECT job!” but much better than it was. The original decoration – damasceening-like effect – was preserved, just a little bit faded, and overall appearance is very acceptable.

[cazclocker]

@Arutha wrote:

@cazclocker wrote:

Paul, I re-read the original post and nowhere does he state that the plate is lacquered. He says it has a “decoration” on it – which I believe was his word for the rather odd attempt at a damasceening-like effect on the plate’s surface. I didn’t see any indication that it was lacquered.
…Doug

Hi Doug,
I may be mistaken but certainly this side of the pond I have yet to see plates that have damaskeening of any kind that have not then be lacquered. In wanting to keep an original finish i would first make sure they are not lacquered before bathing in cleaning solutions which could remove any lacquer.I don’t know how much experience pkamargo has with lacquered clock plates and also as these posts are often read by beginners I feel it is always best to er on the side of caution.
Paul.

Paul, I stand corrected! It is indeed ALWAYS best to err on the side of caution – and, you were very correct to associate with lacquering with a damaskeened surface. Actually, I am glad you pointed that out…thanks!
…Doug in Arizona

[cazclocker]

@pkamargo wrote:

OK, so I first tryed the polishing paste without rubbing. Cleared a little the tarnish, but not enough.

Then I tryed something that is supposed to be around 80% oleic acid – olive oil. No effect at all.

Third test, something that I always use to brighten clock chains: vinegar. And yes, it worked. Just soaking and softly rubbing my finger tips for a minute to get all tarnish gone. Then I made a little mistake: used paper towel to wipe and dry. The paper was not soft enough and made the bottom of the plate a little dimmish. Should have rinsed with water and heat dryed.
Then I soaked in a solvent to remove the original lacquer, dryed carefully… 🙄 And re-lacquered.

Picture below show the result. I’ll not say “What a PERFECT job!” but much better than it was. The original decoration – damasceening-like effect – was preserved, just a little bit faded, and overall appearance is very acceptable.

pkamargo, congratulations! You’ve made a huge improvement with the looks of the plate. Hooray! Did you remember to peg out the pivot holes again, after the lacquer dried? Anytime you re-lacquer a plate, little bits of the lacquer is likely to end up in the pivot holes…just waiting to gum up the ability of the wheel’s pivot from rotating freely!
…Doug in Arizona

[bernie weishapl]

That is a great job. I always spary lacquer with a airbrush. I put toothpicks in the pivot holes because I am to lazy to use pegwood and acetone. Like Paul I have never in 30 yrs seen a damaskeened plate that didn’t have lacquer.

[chris mabbott]

PK, that looks a lot better How did you remove the left over lacquer?

At the end of the day, we all find our own methods based on the experience of others, availability of products in our geographical area, and finally, what suits us best 😆

I forgot earlier to post an interesting article about this very subject…

http://www.abbeyclock.com/brass2.html

[arutha]

A great job and thanks for posting up the pictures
Paul.

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