[TheForge] Patinas

[Bruce Freeman]

The following link calls for the use of a number of chemicals for
patination.  I won't make this a treatise, but I do want to convey some
of the hazard of some of these.  Off the top of my head...

Acetic Acid (6% soln.) -  Innocuous.  Otherwise known as white
vinegar.

Ammonium Chloride - Fairly innocuous.

Ammonium Hydroxide - Aqueous ammonia.  Household ammonia is a fairly
dilute example.  Commercial strength, this stuff can be hazardous to
skin, eye and lungs.  Asphixiating odor gives you some warning.

Bismuth Nitrate - I don't know much about the hazards of this.  Bismuth
is apparently not very toxic, if at all.  Nitrate is an oxidizer, and
can react with "fuels".    

Calcium Chloride  - Innocuous.  Used to melt ice on sidewalks.
    
Cupric Acetate       
Cupric Nitrate       
Cupric Sulfate - Cupric (copper) salts are toxic, so don't eat them or
get (much) on you.  Nitrate is an oxidizer.  

Distilled Water - Don't drink it (tastes lousy)  

Ferric Chloride       
Ferric Nitrate       
Ferrous Sulfate  - Iron salts.  Believe it or not, iron has some
toxicity, so avoid eating this stuff.  Ferric Chloride and Nitrate are
oxidizers.    

Glacial Acetic Acid - Nasty stuff.  Strong vinegar odor.  Flammable. 
Get it on your skin, it penetrates and gives an acid burn down deep. 
Avoid if possible.

Lead Acetate - Sugar of lead. Tastes sweet (they tell me).  Lead is a
deadly, cumulative poison.  Don't eat it or get it on you.     

Nitric Acid 10%  
Nitric Acid Concentrated - Nitric is a nasty acid.  Handle with care. 
Add acid to water, not water to acid.  A strong oxidizer.  Dissolves
copper.  Add a little chloride and it (aqua regia) dissolves gold.  Know
what you're doing before you use this stuff, even diluted.   

Oxalic Acid - Toxic.  Use care in handling.  Don't eat.

Potassium Permanganate - A strong oxidizer.  Reacts with "fuels". 
Stains purple, then brown.  Use with great care.

Sodium Acetate       
Sodium Chloride  -both innocuous.     

Sodium Thiosulfate - A fairly strong reducing agent.  Handle with
respect.      

Sulfurated Potash.  Liver of sulfur.  Potassium sulfide.  Stinks.  The
stink is VERY toxic - Hydrogen Sulfide gas.  As deadly as hydrogen
cyanide gas (used in gas chambers).  The stink gives you some warning,
but lets you down when your nose fatigues.  Liver of sulfur can be
handled safely with adequate ventillation.
    
Zinc Sulfate.  Zinc is toxic.  Handle with care.  Don't eat.

Bruce
(A chemist)
NJ       


>>> "Mark A. Pesetsky" <pesetsky at Princeton.EDU> 3/18/2005 1:38:31 PM
>>>
http://www.coscosci.com/patinas/patinaformulas.htm 

Mark