Where the
world gathers for metal finishing
Q&As since 1989


-----

How can I clean/shine 1943 steel pennies?

2007

I have 100 1943 steel pennies I want to get the gunk off of, and then perhaps buff them up, (and use in refrigerator magnets). Before I go in for any chemical reactions to clean them I want to "wash" then all different ways to cut the grease, or any other kind of superficial stuffs. What would you suggest that I use as "soap/detergent"?(If I'm going to let them "soak" what's a reasonable amount of time?) I know I have to take off oxidation stuff ((rust)after that. What's the best way ? Just buff them (a hand held Dremmel and a wire brush head), some simple "kitchen chemistry" - for instance what? I know for copper pennies a bath in vinegar [in bulk on eBay or Amazon] and salt is supposed to work. But what proportions and amount of time ? I'd even go for electrolysis (using a 6 or 9 volt phone power converter, as was suggested for copper pennies in another answer elsewhere,- though I don't know if it applies to steel pennies. Does it ?) Is doing the electrolysis, a totally different thing, then a chemical reaction ? Which would be better ?

Henry E. Nass
"mature" student - New York, New York

---

2007

Don't soak them; that will only cause corrosion and rust. I'd try the Dremel [on eBay or Amazon] (at slowest speed and softest buffing wheel) with something like Soft Scrub [affil links] on one.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

Try 5% ammonium citrate solution(take 1 lit water/50 gm citric acid [on eBay or Amazon] +add some ammonia-pH must be 3,5). When object is clean(after 10 minutes to 12 hours, it depends on amount of rust) neutralize with 5% baking soda [on eBay or Amazon] solution and then rinse it well.Hope it helps and good luck!

Goran Budija
- Cerovski vrh Croatia
2007

---

2007

The second answer sound like there's some real chemistry at work. I'm a bit clueless as to where to start. ammonium citrate - do I buy citric acid at a drug store or do I have to find a chemical company, or is it at the supermarket at some other name (lemon juice?)? And "some ammonia"_ does one keep some sort of meter in the liquid and keep adding until the meter shows 3.5. Will that be just a few drops ? or a test tube full?)I suppose I just eyeball it until it looks "clean". But should I be stirring it ?Will the solution be getting darket or dirty, or weaker as I get more and more of the batch done ? Do I do a few pennies at a time, or the whole lot ? (I suppose I do this all in some sort of glass beaker [beakers on eBay or Amazon], or can it be in anything plastic, e.g. a two liter soda bottle, and maybe shake the whole thing, to get both sides of the pennies exposed and speed it up ? 5% baking soda - first I'll have to check the box. I'm assuming that's the Arm and Hammer Brand in the Supermarket, but how do I get it to 5%? by weight ? with the ph meter again ? Is "rust" only the brown kind or is it any kind of surface coat that's not shiny ? I'm thinking that the baking soda is like the old kind of dark room photo stop or fix, and its a quick in and out. Is that more or less it ? then rinse !
Thanks for initial basic instructions but now I have to go step by step, for each solution and "bath". Suggestions ?

Try 5% ammonium citrate solution (take 1 lit water/50 gm citric acid + add some ammonia-pH must be 3,5). When object is clean(after 10 minutes to 12 hours, it depends on amount of rust) neutralize with 5% baking soda solution and then rinse it well.Hope it helps and good luck!

Henry E. Nass
- New York, New York

citric acid from supermarket is OK.5% baking soda solution=50 gm baking soda/ 1 lit water.For pH correction you need pH test paper or you can use only citric acid solution(if you think that pH measuring is complicated).I think that you can work with small batches of pennies(more controlled variant of process).Hot solution works faster.Remove rust with tootbrush an some precipitated chalk,and repeat process until you think that job is finished.Then neutralize and thats all.Hope it helps(little bit) and good luck!

Goran Budija
- Cerovski vrh Croatia
2007