- Tape baking
Tape baking is a process that is used to restore
magnetic tapes: audio cassettesand video tapes. It cannot be used with acetate tapes. [cite web| last =Cilleti| first =Eddie| title =If I Knew You Were Coming I'd Have Baked A Tape!| url =http://www.tangible-technology.com/tape/baking1.html| accessdate =2006-12-20]
How baking works
Tapes deteriorate because of a breakdown in the binder that holds the
oxideatoms on the tape. The binder contains polyurethane, which soaks up water and causes the urethaneto rise to the tape's surface. This problem is known as the 'sticky-shed syndrome' (see references below). Short strands of urethane were most commonly used in tapes (until it was discovered that middle-sized strands are better) and were good at absorbing moisture. [cite web| title =If I knew you were coming, I'd have baked a tape.| url =http://www.tiguersound.com/Studio_Information/TapeBake.html| accessdate =2006-12-20] Baking the tape temporarily restores the tape so that it can be safely copied to another tape or a different format. After baking, the tape usually remains in good condition for approximately a month. If the tape re-deteriorates, it may be possible to bake the tape again.
When to bake tape
There are some important signs that show when a tape needs baking. The typical symptom is squealing when the tape passes the playback head or other fixed parts of a tape player. The squealing is audible directly from the tape and also transmitted electronically through the output of the tape recorder. Continuous use of a squealing tape risks permanently damaging the tape, as
oxideis sometimes torn off the tape. This flaking residue can be seen and can feel gummy while still on the tape's surface. There is also a risk of damage to the player. Another symptom is the tape sounding dull and distorted. In a video recording, degradation can be represented by audio-visual dropouts. [Van Bogart, J. W. C. (1995). "Magnetic tape storage and handling. " Washington, DC: Commission on Preservation and Access.]
Deterioration can happen to any tape, but the problem is more common with audio recording tape manufactured in the
USAsince the mid 1970s.
Methods of baking tape
There is no clear method or procedure for tape baking. Baking between 50 and 60 degrees C (120 and 140 degrees F) for approximately eight hours is one method. Normal domestic ovens are not used, as it is not possible to set and maintain the precise temperatures needed; [gas ovens must not be used due the high moisture content that is a byproduct of natural gas heating] particularly at the very low temperatures required for tape baking. Instead, convection ovens or food dehydrators are used. Tom Neuman, Senior Staff Engineer at
Ampex, knew of one extraordinary case where “a record company constructed their oven from a cardboard box, a hair dryer and a candy thermometer.” [Rarey, R. (1995, October). Baking old tapes is a recipe for success. "Radio World". Retrieved February 10, 2008, from http://www.airmedia.org/PageInfo.php?PageID=197 ] [http://www.airmedia.org/PageInfo.php?PageID=197] In 2002, Eddie Ciletti, Mix Magazine’s technology columnist, confessed to building a hair-dryer-powered Easybake oven to rescue his tapes. [Ciletti, E. (2002, July 1). Sleep like an Egyptian. "Mix Magazine". Retrieved February 10, 2008, from http://mixonline.com/mag/audio_sleep_egyptian/index.html] [http://mixonline.com/mag/audio_sleep_egyptian/index.html] Most experts recommend not baking reel tapes wound on plastic reels, because the plastic reels can warp and become deformed; metal reels generally hold up well.
Acceptance and Alternatives
Dr. John Van Bogart at the National Media Laboratory has recommended the process, as well as the tape manufacturer
Ampex, the sound recording industry magazine, "Mix", the Association of Moving Image Archivists and the American Folklife Centerand the Motion Picture, Broadcasting & Recorded Sound Division of the Library of Congress. However, The National Recording Preservation Boardhas put forth their desire to find a better remedy for sticky shed syndrome. It appears the roundtable meeting of March 2006 acknowledged that there is a destructive element to tape baking. [National Recording Preservation Board. (2006, March). "Capturing analog sound for digital preservation". Retrieved February 10, 2008 from http://www.loc.gov/rr/record/nrpb/nrpb-clir.html] [http://www.loc.gov/rr/record/nrpb/nrpb-clir.html] One alternative was presented in 1994. Marie O’Connell was preserving and digitizing at an archive of Radio New Zealand. She began the steady application of isopropyl alcohol to tapes with sticky shed and loss of lubricant after baking had not worked. This method appears to control friction by simultaneously keeping the tape cool and lubricated as they play. [O’Connell, M. (2006, March 9). "Wet playing of reel tapes with Loss of Lubricant." Retrieved February 10, 2008, from http://richardhess.com/notes/2006/03/09/wet-playing-of-reel-tapes-with-loss-of-lubricant-a-guest-article-by-marie-oconnell/] [http://richardhess.com/notes/2006/03/09/wet-playing-of-reel-tapes-with-loss-of-lubricant-a-guest-article-by-marie-oconnell/] O’Connell has patented her Isopropyl Drip Machine and was the Audio Archivist at the Oral History Unit at the University of Southern Mississippi & the Chief Audio Archivist of Cups N’ Strings Studios of California. [Cups ‘N Strings Studios appoints archivist Marie O’Connell. (2006, November 6). "Mix Online". Retrieved February 10, 2008, from http://mixonline.com/news/headline/cupsnstrings-archivist-marieoconnell-110606/index.html] [http://mixonline.com/news/headline/cupsnstrings-archivist-marieoconnell-110606/index.html] No information has been revealed about the long-term condition of the tapes once this process has taken place. Marie O'Connell is now back at Radio New Zealand Sound Archives/Nga Taonga Korero as the Analogue Tape Specialist - www.soundarchives.co.nz
* [http://www.videointerchange.com/tape.htm Lots of info on recovering vintage video(tapes)]
* [http://www.audio-restoration.com/baking.php Explanation on "sticky-shed" syndrome]
* [http://www.geocities.com/Vienna/3941/stickyshed.html 'Dealing with "sticky-shed syndrome]
* [http://www.archivists.org/glossary/term_details.asp?DefinitionKey=3071 Society of American Archivists definition of 'sticky-shed syndrome]
* [http://recordist.com/ampex/docs/misc/sticky-shed.html list of some specific analog reel tape types and manufacturers known to require baking]
* [http://www.amianet.org/publication/resources/guidelines/videofacts/commonprobs.html Association of Moving Image Archives on sticky-shed syndrome for Videotape]
* [http://www.youramerica.net/tapebake.htm Step-by-step guide on tape baking by Dave Luepke]
* [http://mixonline.com/mixline/cupsnstrings-recordplant-021907/index.html Cups ‘N Strings saves 50 Record Plant live recordings.]
* [http://www.masterdigital.com/24bit/analogtape.htm MasterDigital Corporation]
* [http://mixonline.com/mag/audio_master_preservation/ Master preservation]
* [http://palimpsest.stanford.edu/byform/mailing-lists/arsclist/ Tape Resources Online]
Holmes, T. (Ed.) (2006). The Routledge guide to music technology. New York: Taylor & Francis Group.
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