Polishing bullet 20mm case

[tailor marc]

Hey guys,
I know one main rule when collecting historical militaria and thats being very careful when cleaning and using only the best and right stuff.

I was lucky enough to have a marine on an aircraft carrier give me a 20mm shell case off
the 20mm falnex when it was in Fremantle. Since then ive had to look at this boring case with no head and wonderd how i can get a head for it because of out crap laws in Australia ( thats another story).
What i want to know is what is the best way to polish it up without damaging it so it will last looking nice and clean and shiny? I would never to this to a ww2 or older rarer round but this is one i want to get a head for , clean up for a display.

Regards
Marc

[LizardKing]

Hello Marc!
Last summer i came across 10-15 20mm german flak cases... They were in an old barn in Crete so their condition was very poor but there had no rust holes. Only surface rust!
So i took them and after removing all i could (dust, soil, grass etc.) with my hands i moved on the next step.

I took a bucket large enough to completely sink all my items in and i placed 1/2 vinegar and 1/2 water. When i placed them in i covered the top of the bucket so the vinegar wouldn't evaporate. The time limit for the items being left there is calculated by the items. What i mean is you will judge the time by the thickness of the metal. If it is a thin metal you will leave it there for 7-8 hours. If it is a thick metal you will leave it for 14 and maybe more. This is done because the vinegar can destroy the metal if left inside for a long time.
You will have to check your items in distances of 2-3 hours after they are in. Feel the rust with your hands and scratch the surface with your nail to see if it has become easier to remove.
When you feel it is time to remove the items from the bucket you will see that the mix has changed color and most of the rust and dirt has come off by itself.
After that clear your items with water.
Take a soft metal brush and start scratching VERY VERY gently your items. You may need something with a sharp edge to remove big parts or concentrated rust (like a screwdriver or something but cover the edge of it with something soft like a napkin or a small towel so you will not harm the metal if your hand slides off the part with the rust).
You may need a smooth sandpaper but use it with extreme caution and small round moves.
After all these steps you will see that the item you have has completely changed its look and small details will start to appear that were not visible before (i found a lot of eagle stamps and waffen marks on my cases).
Minor damages may happen but if your item isn't one-of-its-kind or very expensive it's ok.
I scratched one case when using the brush and the sandpaper but i don't care as you have to learn by doing!
After that you may want to move more by using a polishing machine! When i tested the polishing machine on one of my relics ( a mortar shrapnel) i found it works perfectly when using a soft brush. It removes nearly everything and gives a nice nearly shiny look to your items.

Other people prefer electrolysis but i'm not familiar with that method since i need someone to show me! Youtube is ok but first hand experience is better...

I hope you the best and i would love to see your items before and after your try!!

All the best,
Michael

[Glenn66]

It sounds like your shell is only tranished, not corroded so why not just use something like brasso, autosol and/or a jewellery polishing cloth?

[tailor marc]

Thanks so much for the advise guys , i really appreciate it!
Yeah this is only a little tarnsished. I was worried brasso may lead to corrosion. I was thinking ,aybe brasso then some type of oil over it to help heep it really shiny