Classical Numismatics Discussion
  Welcome Guest. Please login or register. 10% Off Store-Wide Sale Until 2 April!!! Explore Our Website And Find Joy In The History, Numismatics, Art, Mythology, And Geography Of Coins!!! Expert Authentication - Accurate Descriptions - Reasonable Prices - Coins From Under $10 To Museum Quality Rarities Welcome Guest. Please login or register. 10% Off Store-Wide Sale Until 2 April!!! Explore Our Website And Find Joy In The History, Numismatics, Art, Mythology, And Geography Of Coins!!! Support Our Efforts To Serve The Classical Numismatics Community - Shop At Forum Ancient Coins

New & Reduced


Author Topic: Muriatic acid on coins ?  (Read 7457 times)

0 Members and 1 Guest are viewing this topic.

Offline Johnny

  • Conservator Princeps, Comitia Curiata
  • Procurator Caesaris
  • Caesar
  • ****
  • Posts: 1401
Muriatic acid on coins ?
« on: August 06, 2007, 02:03:30 pm »
I've heard here and there mentionned about the use of  muriatic acid for the really crusty ones,  anyone else ever try this method ? and if so  what are the risks to the coin ?  and to the Patina  ?

I have a few really crusty ones  ( concrete ) regardless of soaks,  are not softening at all

Thanks for any advice

Offline Rich Beale

  • Procurator Caesaris
  • Caesar
  • ****
  • Posts: 663
  • Nec Aspera Terrent
    • ROMA NUMISMATICS
Re: Muriatic acid on coins ?
« Reply #1 on: August 06, 2007, 02:24:45 pm »
Muriatic acid will swiftly stip everything off a coin, including the patina. It will leave the coin with a funny brown colour, or so I'm led to believe. I have never felt the need to resort to such drastic measures. If you want to explore acids, why not start with some plain old citric acid? Lemons are far easier to come by...

Offline bruce61813

  • Conservator
  • Consul
  • ***
  • Posts: 234
Re: Muriatic acid on coins ?
« Reply #2 on: August 06, 2007, 02:43:52 pm »
Muriatic acid is industrial HCl, and probably the wost acid to use on bronze because ogf the CL component.  there are a number of risks to the coin, so I would avoid it. If you need to remove a really thick layer, I would recommend something like Rust Out, or Ka-Boom. they are both acid based , but lower in concentrations.

 Don't give the coin an extended soak. Just put on a little, wait about 3 minutes and scrub under running water. Just keep repeating this. When you have removed as much as you want, soak the coin in a solution of baking soda and water for about 15 minutes, then scrub under running water.

Acids and copper based alloys don't mix very well.

Bruce
too many coins - too little time!!

Offline Johnny

  • Conservator Princeps, Comitia Curiata
  • Procurator Caesaris
  • Caesar
  • ****
  • Posts: 1401
Re: Muriatic acid on coins ?
« Reply #3 on: August 06, 2007, 02:50:58 pm »
thanks for the info,

 guess I'll stay away from Muriatic acids

Offline bruce61813

  • Conservator
  • Consul
  • ***
  • Posts: 234
Re: Muriatic acid on coins ?
« Reply #4 on: August 06, 2007, 08:57:24 pm »
Okay, just to make a believer out of everyone, Don't Use Acid on Bronze!! Here are two pennies tha t I pulled out of my pocket change. They started with about equal wear and tone - this is the difference after 2 minutes in Whink Steam Iron Cleaner, and this uses acetic acid and sulfamic acids, not even HCl. These were scanned side by side, no corrections to either coin.


Bruce
too many coins - too little time!!

Offline Raymond

  • Consul
  • ***
  • Posts: 306
  • I want to be a coinnoisseur
Re: Muriatic acid on coins ?
« Reply #5 on: August 07, 2007, 11:37:06 am »
does the dot above the 2002 make the penny special?
Raymond
Raymond
(Tetricus is not a game)

Offline DruMAX

  • Caesar
  • ****
  • Posts: 424
  • Pecunia non olet
    • Cache Coins
Re: Muriatic acid on coins ?
« Reply #6 on: August 07, 2007, 11:46:03 am »
Quote from: bruce61813 on August 06, 2007, 08:57:24 pm
Okay, just to make a believer out of everyone, Don't Use Acid on Bronze!! Here are two pennies tha t I pulled out of my pocket change. They started with about equal wear and tone - this is the difference after 2 minutes in Whink Steam Iron Cleaner, and this uses acetic acid and sulfamic acids, not even HCl. These were scanned side by side, no corrections to either coin.


Bruce


I cleaned a coin in a vinegar and salt solution that ended up looking like that...cleaned it real well but left it looking pinkish.

Offline Ardatirion

  • Procurator Monetae
  • Caesar
  • *****
  • Posts: 498
  • Veni, vidi, vomui.
Re: Muriatic acid on coins ?
« Reply #7 on: August 07, 2007, 12:35:34 pm »
I don't think that the dot is actually on the coin.

Offline bruce61813

  • Conservator
  • Consul
  • ***
  • Posts: 234
Re: Muriatic acid on coins ?
« Reply #8 on: August 07, 2007, 01:56:13 pm »
I don't think that the dot is actually on the coin.

I'll have to look, but these are as scanned, I put them on the scanner together. It might have been an error coin!

DruMax - the pink is raw native copper color, and vinegar is made of acetic acid. That is why acids are not recommended for bronze. In hand it is not as pink, but it is different in color if you compared its color  to a new penny.

Bruce
too many coins - too little time!!

Offline areich

  • Tribunus Plebis Perpetuus
  • Procurator Monetae
  • Caesar
  • *****
  • Posts: 8706
    • Ancient Greek and Roman Coins, featuring BMC online and other books
Re: Muriatic acid on coins ?
« Reply #9 on: August 07, 2007, 02:43:11 pm »
I'm betting it's a speck of dirt on the scanner, especially if you got that black
background by scanning with an open lid.
For convenience I've removed the lid on mine and it just seems to attract all kinds of dirt and dust!
Andreas Reich

Offline Robert_Brenchley

  • Procurator Caesaris
  • Caesar
  • ****
  • Posts: 7307
  • Honi soit qui mal y pense.
    • My gallery
Re: Muriatic acid on coins ?
« Reply #10 on: August 07, 2007, 06:37:07 pm »
I'd never use a really powerful acid on a coin, especially not hydrochloric! if you want to use acid, use a weak, dilute one, like lemon juice or vinegar, monitor like mad, and don't use them at all on patinated AE's.
Robert Brenchley

My gallery: https://www.forumancientcoins.com/gallery/index.php?cat=10405
Fiat justitia ruat caelum

Offline Johnny

  • Conservator Princeps, Comitia Curiata
  • Procurator Caesaris
  • Caesar
  • ****
  • Posts: 1401
Re: Muriatic acid on coins ?
« Reply #11 on: August 08, 2007, 02:02:30 pm »
As I stated earlier,  and even more so now, since all this feeback was given,  I'll stay away from Acids alltogether.

thanks to all for the help

cheers

 

All coins are guaranteed for eternity