I believe it was hydroflouric acid that doused the poor bastard from Sanitation, used in Prosoco Heavy Duty Restoration cleaner and other products.  Muriatic, which is hydrochloric acid produced as a byproduct of iron foundry production is not pure hydrochloric but laced with substantial amounts of dissolved iron.  That's why masonry cleaned with muriatic will not only leach white salts from the deposited chlorides but will also leave brown ferric stains.  Nasty stuff despite Martha Steward's recommendation for it in her cleaning articles.


  ----- Original Message ----- 
  From: Ken Follett 
  To: [log in to unmask] 
  Sent: Thursday, June 14, 2001 8:38 AM
  Subject: Re: White


  In a message dated 6/13/01 7:42:58 PM Central Daylight Time, 
  [log in to unmask] writes: 


    According to the story the driver was not found.... 


  I believe it was sometime last year that a NYC sanitation worker was injured 
  on encountering a gallon of muriatic acid that they had unkowingly thrown 
  into the rear of the garbage truck. When they went to compact the load the 
  plastic container burst. I'm not sure if the worker survived, or not, at this 
  point. 

  Muriatic acid is often used for cleaning of masonry, particularly to remove 
  excess mortar stains. Though it is generally not accepted in mainstream histo 
  presto in NY. I remember using it quite often with the stonemasons that I 
  learned from in building of fireplaces and stone patios. It sometimes turns 
  up in restoration work, at least in NYC, and quickly identifies contractors 
  that are not very sophisticated or knowledgeable in histo presto. I have no 
  context to say that it is not used in histo presto in other areas than NYC. 

  I am always curious as to differences in understanding of preservation 
  technique and practices between geographic locations (city to city, country 
  to country) or between urban and rural. 

  I can say that what goes for good histo presto in the Montauk community is 
  not what will work in NYC. 

  ][<en