12423
Title Of Article Chaper
The Barrow two-bath deacidification method
Title Of Journal Book
The American archivist
Volume
39
Issue
2
Pages
161-164
Literature Type
Serial
Literature Level
Analytic
Abstract
This article is a response to the confusion over the preparation and use of deacidifying solutions used in the Barrow Two-Bath Deacidification Method. It details the means of preparing and handling the Barrow process solutions. Essentially, this process involves treatment of a document for twenty minutes in each of two solutions. The first solution is one of approximately 0.15 percent calcium hydroxide, or 1.5 grams per liter of calcium hydroxide, which is a saturated solution since this is the maximum solubility of calcium hydroxide at 25°C. This solution neutralizes any acids present in the document being immersed. After the excess calcium hydroxide solution is drained off, the document is soaked in the second bath, 0.15 percent calcium bicarbonate solution. This converts the highly alkaline calcium hydroxide to calcium carbonate. When the sheet is dried, calcium bicarbonate, which exists only in solution, is also converted to calcium carbonate as a finely divided precipitate throughout the fibers of the document. The Barrow lab often uses this deacidification process in connection with their lamination procedure. The lab has not noted any evidence of cellulose degradation from the initial high pH due to the first bath. -- AATA
pub_id
12423