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Restoring patina on case

Falcon

Well-Known Member
Today I got an unfired 76mm ARMD.C. case from the car boot. However, someone has polished it so it is shiny to the point where you can see your reflection in it. It looks awful. Is there any way I can dull the brass down again?
 
Ive had limited success dulling down brass using a blow lamp , play the flame over it and soon it will start to dull down
 
Shell restoration

Try scotchbrite. Its a nylon scouring pad, similar to what you might use in the kitchen, That should take the shine off. You then need to apply heat to the neck to re-create the blue / grey colouring.
Cheers
Hangarman
 
darkening brass

Hello Sir Falcon;

I had read some time ago a trick to darkend brass. I don't know if this works, Just try it to scrap brass metal first to see the results before doing it to your shell...:)

Just expose the brass surface to household ammonia to darkend the brass surface...:)

Hope this could help...:)

Best regards;
andrew
 
Opps... I mean expose the element to fumes from household ammonia, not direct contact with ammonia. i mis typed the word fume..:)
 
Or you could just wait for a few years.

20 years ago when I first started collecting everything got polished, then 15 years ago I realised they looked better with the old patina and that I didn't fancy polishing hundreds of rounds and just left them - now they look much better. Needless to say ones I get now don't get polished, they get carefully restored (localised areas of coppering etc will get sorted out to prevent further damage etc.)

Dave.
 
Thanks for the input everyone.

I head something a while ago about putting a case (where you are absolutely sure the primer is dead, of course) in the oven on 200 degrees C or so for a while, apparently this causes it to darken. You simply remove it when the case is dark enough in colour.

I will be alright with this, as there is no primer in my case.

Has anyone ever heard of, or tried this method?
 
patina

the best way to get the patina back is to leave it outside in the garden in the rain for a month.
I wouldnt do anything else as you risk damaging it.
 
Thanks for the input everyone.

I head something a while ago about putting a case (where you are absolutely sure the primer is dead, of course) in the oven on 200 degrees C or so for a while, apparently this causes it to darken. You simply remove it when the case is dark enough in colour.

I will be alright with this, as there is no primer in my case.

Has anyone ever heard of, or tried this method?

Can you ever be sure the primer is dead unless you hear it pop yourself? I have a number of rifle/pistol rounds that have a nice impression on the primer but have not gone off.

Also, I am not sure what temperatures are necessary to change the characteristics of the brass. Probably not a big issue.

Finally, I have had zero luck with the ammonia trick. I would just leave it out.
 
cases

Hold off on the ammonia as if I remember my metallurgy correctly it was ammonia fumes from horses waste that caused season cracking in brass cases. I'm sure most of us have seen a cracked WW1 case that doesn't ring when tapped, generally they seem to be French but sometimes British.
As to patina restoring hot sweaty hands take the shine off mine, but the suggestion of leave it outside sounds good as well.
 
What about -

coppering on the brass ? where it looks like it has been dug up or something has causes a reaction ? can this be undone or removed ?
 
I'm fairly sure you can't reverse the process of coppering on brass (I'll leave that one to the metal experts here to answer). What I have found though is that if I get a case that has some corrosion/oxidation on it, green spots etc it is very important to deal with it immediately otherwise the metal continues to degrade. I use a sharp knife to very carefully scrape off the localised area of corrosion/oxidation leaving the rest of the case unaffected.

Dave.
 
I darkened the case with the blowtorch method, it seemed to work quite well as it did take off the gaudy polished shine.

As for the primer, this was not a problem on this case as it has a screw-in primer, and there wasn't one in there when I got the case.
 
coppering

I was told that the copper effect was due to the zinc part of the brass leaching out and was not therefore reversable, however if only light you can try wet and dry to remove metal to try and get down to original brass.
 
brass

i supose you could polish the 'staining' out,then leave it in the garden for few weeks to build the patina again.
I usually put a strong stick in the ground and put the case on that up side down...rather like an old trench gas alarm.
Ive even used burnt wood ash rubbed in to the surface whilst being exposed to the elements,it seems to speed up the process a bit.
Just rinse it after a few weeks and see what its like
 
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