Hermle 400 day clock

[HectorLooi]

Just got my Hermle 400 day clock in the mail today. It's a non-runner, which was going for a song. The postage was actually more than double its price.

There was absolutely no power going to the escapement, even though the mainspring was fully wound. I thought someone had fiddled with the pallet depth. But on removing the suspension wire and it's shield and applying some force on the 6th wheel, the escapement appeared fine.

On examining the pivots, they didn't appear terribly dirty. Then on more careful examination, I realized that someone had polished the back plate with Brasso while all the pivots were in place. There was Brasso in all the holes!

Looks like I'll have to do a full disassembly and polish all the pivots and holes.

[HectorLooi]

[KarlvonKoln]

That's a beautiful clock!  Looks like the former person who polished it up didn't know the necessity of cleaning all the Brasso off once they were done polishing.  I don't think I've ever used the stuff on clocks but I know the residue needs to be cleaned off with alcohol or some such.  That looks like some work you have ahead of you. 

[watchweasol]

Should scrub up beautifully they are nice little clocks, mine in in the display cabinet with the others,  Brasso the scourge of clock plates,  although never seen it on 400 day clocks be sure you get it all out of the pivots and the holes. Keep you busy for a day or two.

[HectorLooi]

I tried letting down the mainspring but it's wound up so tightly that I can't advance the winding key enough to release the click. I'll have to get the clock in beat and get it running for a couple of days to free up the click. 

The brass is still shiny even after 50 years. Is it bare brass or is it protected with a layer of shellac or varnish? 

The base of the clock is very tarnished, if I repolish everything, how do I keep it shiny?

[oldhippy]

The way of keeping brass as you say shiny is to use a clear lacquer and apply with a good fine artist brush. It drys very quick, just make sure it is absolutely clean and free from tiny hairs/dust particles. This is what I alway used. You need the brass clear.

   https://www.cousinsuk.com/product/lacquers-rapid-drying

[HectorLooi]

Thanks OH. I have a bottle of Horolac lacquer. But I'm worried about getting it into the holes. Do I clean out the holes after the lacquer dries with pegwood or a smooth reamer?

[wls1971]

1 hour ago, HectorLooi said:

Thanks OH. I have a bottle of Horolac lacquer. But I'm worried about getting it into the holes. Do I clean out the holes after the lacquer dries with pegwood or a smooth reamer?

Very few movement plates are Lacquered just clean them and polish with French chalk and a soft brush, blowing out the pivot holes afterward to remove any excess.

I have Lacquered large plates before on one Fusee clock you must block every pivot hole with peg wood before Lacquering, its such a phaff of a process that I would not bother Lacquering any movement plates again plus the next time it needs cleaning it all needs removing again.

Plates that have been chalked should stay bright and shiny for quite a while.

Edited March 12, 2021 by wls1971

[oldhippy]

French chalking will give a lasting shine to any clock movement that has been polished. Yes you need to plug all the holes I used cocktail sticks. Some things do take a time to achieve but what is the rush. Just think how nice it will all look when you see the final results.  

[HectorLooi]

I have a block of French chalk from Cousins. It is very different from the French chalk that I'm familiar with from the days of dental school. The French chalk back then was a very fine powder, with a very soft feel. When it is dusted on Plaster of Paris and buffed, it produced a nice semi gloss sheen. Whereas the French chalk from Cousins is a block of white stuff.

What is the correct way to use French chalk for polishing brass?

[Michael1962]

Phew. I'm glad someone asked before me. I was wondering the same thing.

[oldhippy]

You need what is called a chalking brush, you must always keep the brush clean and never use it for other things, you load the brush by chalking the brush and then brush the plates. It is a very old way of stopping brass from tarnishing. I dear say the chalk of today is nothing like the old stuff and how things change I bet it isn't even the same now as what I bought back in the 70's & 80's. 

[HectorLooi]

Thanks OH.

Now for my next silly question. What does a chalking brush look like?

I  read from another forum that the way to brush French chalk is to use light pressure and brush it as quickly as your hand can move. Is that correct?

[oldhippy]

Correct. All you need is a very soft bench brush make sure it is really soft so it doesn't leave scratch marks on the brass

Natural is best avoided nylon. This type of thing.   

[wls1971]

I use a long handled Glasgow brush with very soft natural bristles, the chalk comes in a block draw the brush across the block to load it with particles of chalk then with no pressure dust it very fast over the plate, I don't quite know why it works so well but I think the chalk must pick up microscopic particles of contaminates on the surface of the plates, but plates I have done a few years ago rather than go a dirty brown from oxidisation and exposure to air take on a sort of golden colour rather than a full on tarnish.

https://www.cousinsuk.com/product/natural-bristle-brushes-handheld

I have used very soft A.F brushes they are absolute rubbish they shed bristles like a malting dog sheds hair.

The plates you brush must be absolutely bone dry after cleaning so that the chalk cant stick in the pivot holes use a blower after dusting to clear any excess chalk from the plates and pivot holes, I have a air compressor for applying Lacquer I use that to blow them clear.

[wls1971]

Another thing I find useful to do is remove the metal posts especially on striking clocks the ones that the rack and rack hook fit to etc, to stop them getting mixed up place them with the corresponding part, there is nothing worse than rapping you knuckles against them when dusting at speed or snagging the brush.

[oldhippy]

You should always remove those posts and clean them up in a lathe using emery sticks or cloth or if you don't have a lathe use your bench vice and use emery cloth. 

[HectorLooi]

I came across this product in Cousin's catalog. What does it do?

[oldhippy]

This what they say about it,

Ideal for removing tarnish from exterior brass door furniturem and restoring it to its original colour. Apply Rustins Brass Restorer with a brush or dipping small items. Also may be used for cleaning copper and bronze.

[clockboy]

Another item added to the never ending leaning curve OH. 
 I have used the lacquer method to stop the tarnishing with great results. However I will try the chalk method for sure.I purchased a job lot of clock/ watch odds and a sods a few years ago and there was a block of chalk included now I know what it was used for.

[wls1971]

1 hour ago, HectorLooi said:

I came across this product in Cousin's catalog. What does it do?

Its exactly the same as Rustin rust remover but with a different label on the bottle 41% phosphoric acid in ethanol and 1% methanol, the rust remover is cheaper. 

A lot of these brass and metal cleaning formulations can be found in old horology books, another good book for formulations, is The Modern Gunsmith by James Howe which has also a excellent section on Bluing and Colouring steel and brass.

The names given to the chemicals can be rather archaic but you can google for the modern equivalents.

[HectorLooi]

I just took the movement apart. Looks like I have quite a lot of work ahead of me. All the pivots look very rough, there is some "lipping" of the pivot of the barrel arbor and 2nd wheel.

I'll have the get my lathe out and polish all the pivots.

[HectorLooi]

1 hour ago, wls1971 said:

Its exactly the same as Rustin rust remover but with a different label on the bottle 41% phosphoric acid in ethanol and 1% methanol, the rust remover is cheaper. 

A lot of these brass and metal cleaning formulations can be found in old horology books, another good book for formulations, is The Modern Gunsmith by James Howe which has also a excellent section on Bluing and Colouring steel and brass.

The names given to the chemicals can be rather archaic but you can google for the modern equivalents.

This item is listed as a hazardous substance on Cousin's and cannot be shipped to my location. Looks like I'll have to brew a batch of my own.

[HectorLooi]

I got the clock all cleaned up and polished. But I'm still struggling to get it running. I know how to get the clock in beat but setting the pallet depth still eludes me.

If I set it shallow, the amplitude is so low that it stops eventually. If I set it deep, the amplitude is not enough to unlock the pallet. So I've been trying to find the sweet spot somewhere in between.

I thought I found it when I came home to find it still running. But alas, it stopped after dinner. So it's back to tweaking it further before bedtime. 

[oldhippy]

Why have you altered the pallet depth?