The original Belgian method that we can document, used sulfuric acid. They simply poured it over the ground barrels. Here is a list of modern restorers:
Buck Hamlin
Pevely, MO
636-479-4304
Steve Bertram
Boulder, CO
303-938-1996
Dale Edmonds
Kansas City, MO
816-444-2040
Keith Kearcher
Bend, OR
541-617-9299
Dewey Vicknair
Ephrata, Pennsylvania
717-733-2145
Feel free to call one of them up. IF they have the time, they will gladly share with you. Each approaches the subject on their own terms, so there are variations.
Pete
