 |
 |
Hi Martin Increasing the baking time sounds sensible, but I'd be very wary of increasing the temperature. It should be fine to rebake the tapes straight away, always bearing in mind that they should never be subjected to thermal shock: place cold tapes in a cold oven then turn it on and allow to heat up. At the end of the given period, turn the oven off and let the tapes cool down inside for several hours, so that by the time the oven door is open they should already be at room temperature. Initial recommendations suggested 8 hours for tape baking, though many archives have noticed that longer (sometimes much longer) is required. Almost all tapes I've dealt with have become playable after baking, the only exceptions being two batches of Agfa double play tape made in the early 1980s which we've yet to find a solution for. A couple of other golden rules regarding tape baking: Always use a lab oven or equivalent, as the temperature will be more accurate. Never bake an acetate-backed tape. It won't be sticky anyway, and the high temperature will permanently deform it. More info here: Henrikson, Juha & Nadja Wallaszkovits, Audio Tape Digitisation Workflow http://www.jazzpoparkisto.net/audio/ http://richardhess.com/notes/formats/magnetic-media/magnetic-tapes/a-bas e-film-primer/ Regards Will ________________________________ From: Discussion list for British & Irish Sound Archives [mailto:[log in to unmask]] On Behalf Of Martin Astell Sound Archivist ERO LS Sent: 30 September 2009 11:49 To: [log in to unmask] Subject: Baking tapes Dear Colleagues, I have been making my first attempts at baking quarter inch magnetic tapes which are suffering from Sticky Shed Syndrome. I started with a batch of four tapes baked at 50 degrees centigrade for seven and a half hours. Two of the tapes were on 17cm plastic reels and two were on 26cm metal reels. For the smaller reels the baking worked well and I have been able to digitise the content. However, for the larger reels the baking has not been completely successful. The tape towards the centre of the reel is still sticky. I assume, therefore, that I need to bake these tapes for a longer period (perhaps at 55 degrees). My question is - should I bake these two tapes again straight away or should I leave them for a few months to return to their original state before baking them for a second time? Or does it not matter? Thanks in advance for any advice or thoughts. Regards, Martin Martin Astell Sound Archivist Essex Record Office, Wharf Road, Chelmsford CM2 6YT Essex County Council | telephone: 01245 244624 | extension: 23624 | email: [log in to unmask] P Please consider the environment before printing this e-mail ________________________________ This email (including any attachments) is intended only for the recipient(s) named above. It may contain confidential or privileged information and should not be read, copied or otherwise used by any other person unless express permission is given. If you are not a named recipient, please contact the sender and delete the email from your system. It is the recipient's responsibility to ensure that appropriate measures are in place to check for software viruses. ************************************************************************** Experience the British Library online at http://www.bl.uk/ The British Library’s new interactive Annual Report and Accounts 2007/08 : http://www.bl.uk/knowledge Help the British Library conserve the world's knowledge. Adopt a Book. http://www.bl.uk/adoptabook The Library's St Pancras site is WiFi - enabled ************************************************************************* The information contained in this e-mail is confidential and may be legally privileged. It is intended for the addressee(s) only. If you are not the intended recipient, please delete this e-mail and notify the mailto:[log in to unmask] : The contents of this e-mail must not be disclosed or copied without the sender's consent. The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the British Library. The British Library does not take any responsibility for the views of the author. *************************************************************************