Expert: Joe Hylas - 2/21/2007

Question
Hello Joe, I have a coin collection that was submerged by Hurricane Katrina waters.  They sat for at least 2 weeks before we were able to get to them.  I have Proof Sets from 1972 to 1986, Uncirculated sets from 1963 to 1984.  Proof and UNC Ike dollars.  Morgan Dollars and Peace Dollars.  Half Dollars (Seated Liberty, Barber, Walking Liberty, Franklin, Kennedy).  Quarters (Seated Liberty, Barber, Standing Liberty, Washington).  Dimes (Liberty Cap, Seated Liberty, Barber, Mercury, Roosevelt).  Nickels (Shield, Liberty Head, Buffalo, Jefferson).  Pennies (Indian Head, Wheat, Steel, Lincoln.  1893 Columbian Exposition Commemorative Half Dollar, 1951 Booker T Washington Half dollar.  1844 and 1856 Half Dimes, 1851 3-cent piece, 1964 2-cent piece, 1846 and 1849 Large Cents
Half Dollar.  I also have many "Franklin Mint" silver and bronze coins, as well as US Commemorative silver proof coin sets (1982 Washington Birthday, 1986 Ellis Island, 1976 Bicentennial, 1984 Olmpics, 1991 Mt. Rushmore.  It seems the items in 2X2's in vinyl pages and loose coins did well.  But the coins in plastic containers had it pretty bad, some rusted and some turned green from corrosion.  That was mostly the Proof, Commemorative, and Unc sets.  I don't know if I should do anything with them or let them alone.  If I don't see any obvious dirt on the coins should I just leave them alone or try to clean them.  I read that its not a good thing to clean old coins.  Thanks for any help.  

Answer
Hi Mike,
Gee, I'm really sorry to hear of your loss.  Hopefully you had some insurance to cover the coins.
This is what I would do.
Find a big working surface and cover it with a few bath towels.  Unless the coins were in airtight holders, you have to assume that they got wet.  Even items in Govt issue holders are not sealed.
Take every coin out of the holders and place them on the bath towel being sure to handle the coins only by the rim.  Do not slide the coins in any way.   Merely place them gently on the towels.  Any cardboard holders should be discarded as they are most likely contaminated.
You will have to replace every holder or risk long term damage to the coins.
There are a number of solutions you can use as a dip to decontaminate the coins.   Commerical products such as JEWELUSTER will remove contamination but will also remove any toning.  Not every coin will loook like new again depending upon how harshly the were contaminated.  You simply pour some of the solution into a bowl, dip the coin in for 3-4 seconds and rinse under clean water.  The coins should then be patted dry, do not rub them.
You can also use acetone.
Once every coin is dipped and dry, repackage them in new vinyl flips.  
the dipping works on silver and gold.  Do not use it on copper as it will make the coins a funky color.  the green on the silver coins is the PVC in the vinyl breaking down, that should dip out.
Good Luck!
Regards
Joe Hylas