[sci.physics] Reverse Rusting?

adams@swbatl.UUCP (4237) (12/04/89)

I'm curious about a process I just saw mentioned in the local paper.  This 
occurred in a article acquired from the London Observer [wire] Service, about 
a late 14th century cannon found in the ocean off the coast of North Carolina.

I'll quote:

	When the cannon was retrieved it was fully loaded with a
	ball and with gunpowder that was still tightly packed and
	and dry.  Electrolysis was used to reverse rusting, and the
	cannon was cleaned,  dried in a kiln, painted with tannic 
	acid and sealed with micro-crystalline wax.

Just what can be done to "reverse rusting?"   What are the limits and costs of
this technology?  What is the significance of the post-electrolysis processing?
I'm mostly curious, not planning to reignite the "corrosion wars" nor hoping 
to profitably restore my collection of rusty nails :).  The cannon, by the way,
was significant because it was of the type onboard a ship used by the 
"lost colony" of Roanoke Island, and could help solve the 400 year mystery
about the disappearance of the first English colony in America.
-- 
#	---Tom Adams---	| uunet!swbatl!adams or adams@swbatl.swbt.com
# I collect pre-1930 wireless, electrical and scientific books.
# opinions... Opinions? I don't think I'm allowed to have opinions.