Fresh acid would be my choice… Sulphuric or citric..whatever comes your way..

I've used vinegar to remove oxide coating from phosphor bronze, and I think it'd work for brass. It hadn't occcurred to me that it'd preferentially react with one component of the alloy, but I think the effect would be minor unless you left it in for days.

I'd think it depends on the depth of the corrosion and how much metal's going to be sacrificed. It's usually important to preserve manufacturing and inspection stampings – abrasive polishes can be very destructive to those.

Have you considered clock cleaning solution recipes? Ammonia, oleic acid (liquid soap) and a pinch of acetone diluted down with water. But don´t leave it in too long.

Not sure how it would work on copper, but Apple Cider Vinegar will dissolve the worst corrosion imaginable on brass and leave it looking like new.

Apple Cider, Coca Cola, or any fruit drink will work, but citric acid is probably the best and safest method. The fruit drinks may leave the item a bit sticky, but that will wash off with hot water.

Ian S C

If you don't want to atack the brass use an alkali. As has already been mooted Horolene is designed to clean old and dirty brass clocks without damage so why not use the right product for the job.

regards Martin

Not knowing how much they have oxidised or the condition,

I had good results from using combinations of mixtures of washing liquid, clean pea shingle, stainless steel cream cleaner and white wine vinegar to remove the inside corrosion/staining of my Avon Jet engine starter cartridges-

More to do though.

The exterior, I used the old formula T cut and elbow grease-

These need more internal cleaning for when I'm ready to convert their use as fuel tanks, but the worst is sorted.

There's another option.

You could clean it, then put a thin layer off brass plate on top. Zinc and copper have the unusual property of being able to be plated simultaneously.

Take a look at this kit:

http://www.gaterosplating.co.uk/index.php?route=product/product&product_id=203

Neil

Has the process damaged the headstamps? I know Duraglit can, and I'd expect Scotchbrite could too – though it might be possible to minimise both.

Looks like Polte of Magdeburg from Feb 1917.

I have a 10,5 cm case by them from May 1916 – currently full of Swiss files.😁

You can see from the short cartridge case that it was a low-velocity round – max range 8,800 M.

More details here:

https://en.wikipedia.org/wiki/15_cm_sFH_13

The wikipedia article has an example of 'send three and fourpence we're going for a dance' in Footnote 5, ie "Robert Graves, in Good-Bye to All That, says "five-nines [were] called 'Jack Johnsons' because of their black smoke"^[4] in reference to "the boxer Jack (John Arthur) Johnson (1878-1946), the first black American world heavyweight champion (1908-1915)."

A little misleading – my recollection is that 'Jack Johnsons' referred to the bursting shells, not the gun that fired them. Unusually at the beginning of WW1, 5.9" German shells were filled with TNT, which goes off with a characteristic cloud of dense black smoke, and (at the time) an unusually violent bang.

'Good-bye to All That' is an excellent book, but I also recommend Ernst Junger's 'Storm of Steel', especially in the less censored early editions. Well worth reading as a reminder that there are people who positively enjoy killing!

Dave