Found a very good cleaner for camera restoration

[ForenSeil]

Some minutes ago I found a cleaner that is able to remove all the dirt of some cameras parts without any scrubbing or harming the object. And I like to share this find.

I'm currently cleaning three old Fed Rangefinders and had a big problem with cleaning the metal grips on the wheels for film spooling.
First I tried a toothbruch with several cleaning aids like comercial metal polish, boiling alcohol (95%+ ethanol and isopropanol), boiling water (with different washing agents (Fairy, etc.)), different boiling petrol ethers (Lighter fuel, etc.) and some more without much success.

After this treatment the grips (still) looked like this:

But than after some thinking about what this dirt could be I tried the ultimate weapon: Household ammonia (9%)
Directly when I put the first wheel in the liquid it began to clean the surface by it self without any mechanical scrubbing

I heated the solution in a microwave for 45s (until boiling) and when it came out the result looked like this:

Back on camera:


Some chemistry:
I guess this happens because the wheels were made of a zinc containing metal alloy. Zinc is able to build an extremly thin oxid/salt layer on it's surface. This surface is selectivly dissolved by the ammonica, because the NH3 in the ammonia is able to produce a solouble complex salt from the insolouble zinc oxides/salts while the elementar zinc remains untouched. As a nice side effect ammonia (as a moderate base) is also able to saponify most fat and waxes and changes some of the dirt into soap in situ

The only drawback is that ammonia is not working as a cleaner for every metal as well as here. It may attack aluminium surfaces slowly (within some minutes) for example. And it removes every patina as fast as the dirt

But I heard theres also such a wonder weapon for cleaning aluminium: Oxalic acid in hot water
Do have any experience with that?

For chrome and silver another great cleaner and rust remover is aluminium foil with coke (yes, the softdrink, it contains phosphoric acid which will work as an good electrolyte and catalyst for this reaction). Works very well, sometimes also with steel (but not as good as with chrome or silver). I used it often to to clean silverware/cutlery and chromed rims of cars. You only have to be careful not to make any scatches with the aluminium foil.

Do you have any other comparable tips?

EDIT: Forgot to say: Be careful handling ammonia. It's corrosive and may irritate skin or damage your eyes if you get the liquid on them. You should wear gloves and goggles. The vapors of ammonia are also very irritant (but on usual doses not very harmful), so open a window.

[stingOM]

I hope you checked out the potential hazards of these chemicals before you boiled (indirect heating I hope, still inhalation risks) them. You could have gotten seriously injured!

Having said that, it is nice to see it worked for you in the end!

[ForenSeil]

[Attila]

I use also ammonia and hydrogen-peroxid mixture to clean lens surface and fungus infected lens elements if need, very powerful and dangerous mix with care works very well.

[ForenSeil]