JFARRINGTON@EAGLE.WESLEYAN.EDU (Jim Farrington) (10/17/90)
Cameron Paine raises some interesting points concerning the relationship of airflow and tape conservation. However, it is believed by most sound archivists and conservators that tape conservation is more a matter of environmental control than anything else. Temperature and humidity control plays the single most important role in determining tape longevity (as well as the longevity of every other library artifact--books, scores, LPs, CDs, personel, etc.). I have never heard air described as a lubricant as most people consider the lubricant to be a part of the manufacturing process just like the oxide, backing, and other components. Rather than suggest that the reel cutouts have anything to do with packing, it seems to me that it might simply be that the particular reels used are warped or in some respect responsible for an uneven pack. Are your tape packs shifting over a period of time? If so, that leads me to believe that the environment in which they're stored is the culprit. (I'm not necessarily ruling out the possibility of cutouts contributing to the problem or solution, I'm just not entirely convinced.) An uneven pack will certainly heighten the effects of print-through. Periodic repacking or respooling of tape has been a recommended practice to redistribute tension in the pack. This is especially helpful where storage conditions are less than ideal (i.e. fluctuating temperature and humidity). What Steve Graham had described sounded to me like that with which we asso- ciate the loss of the whale oil-lubricant. If it is this you can tell because a dark, sticky substance will be left on the tape guides and heads and will take an extra-ordinary amount of Intraclean and swabs to eliminate. The Pellon method is the one that most people use to get that one last pass over the tape heads, and the one recommended by Ampex. Yes, we do use it here and we find it to be very effective. Why it does what it does I do not know. We haven't had a problem with excess oxide shedding (nor any other problems, for that matter) when using it, but I can't say for sure that we've tried it with any BASF tapes. Pellon is described as a non-woven material (the advantage being that it will not shed fibres). I've not had any problems getting it in any fabric store, so I would assume that it's available world-wide. If you're having problems finding it in Australia let me know and I'll send you a swatch via snail mail. It comes in different densities, and we prefer the thicker, denser versions for most applications. Of course, the real question concerns the tapes we're making today. Here it is only ten years later that we're finding out that tapes made then are not lasting the 20-30 year life expectancy due to a manufacuting problem. Do we know whether or not tapes made today are any better? What about DAT? If, or rather when, that tape breaks or dries out or whatever, how in the hell are you ever going to splice it or run it over a piece of Pellon? Much the same can be said for cassettes, but since that is certainly NOT an archival medium one assumes that recordings of significance are recorded not only on cassette. Jim Farrington Music Librarian Wesleyan University JFARRINGTON@WESLEYAN.BITNET jfarrington@eagle.wesleyan.edu ALANET: MLA.NEWS.ED "A librarian ought not to content himself with giving the public what it happens to want, but ought to help create a demand for what the public needs...." Oscar Sonneck, 1917.
exspes@gdr.bath.ac.uk (P E Smee) (10/19/90)
In article <7030@uwm.edu> JFARRINGTON@EAGLE.WESLEYAN.EDU (Jim Farrington) writes: >Pellon is described as a non-woven material (the advantage being that it will >not shed fibres). I've not had any problems getting it in any fabric store, >so I would assume that it's available world-wide. If you're having problems >finding it in Australia let me know and I'll send you a swatch via snail mail. >It comes in different densities, and we prefer the thicker, denser versions >for most applications. It's not called 'pellon' everywhere, but the word 'non-woven' (perhaps suitably translated) often comes up in the name. Basically, go into any serious fabric-and-patterns shop. They should get you the right stuff if you ask for non-woven interlining or interfacing. If you are uncomfortable trying to use the jargon of an unfamiliar speciality (sewing) then just tell them you want some of the funny white stuff that you put into collars and cuffs to stiffen them when you're making a shirt, in the 'heaviest weight'. They'll know what you mean. If (by some chance) they've got a stock of the older woven interlining around, you'll be able to tell it's not the right stuff. -- Paul Smee, Computing Service, University of Bristol, Bristol BS8 1UD, UK P.Smee@bristol.ac.uk - ..!uunet!ukc!bsmail!p.smee - Tel +44 272 303132
bill@uunet.UU.NET (Bill Vermillion) (10/19/90)
In article <7030@uwm.edu> JFARRINGTON@EAGLE.WESLEYAN.EDU (Jim Farrington) writes: >Cameron Paine raises some interesting points concerning the relationship >of airflow and tape conservation. ... I made comment on this thread yesterday and today Audio magazine arrived and there is a lengthy discussion on the tape problems. One thing that struck me from the charts included is that hydrolysys is a problem. Too high a humidity will cause much degradation.. THe processing available from Agfa is also mentioned, but only for agfa customers it appears, and its in the neighborhood of $250 per 2500 feet. I suggest reading of the article well answer most questions. bill -- Bill Vermillion - UUCP: uunet!tarpit!bilver!bill : bill@bilver.UUCP
billn@hpcvaac.cv.hp.com (bill nelson) (10/22/90)
You can get silicon impregnated cloths at any hardware store that sells firearms. The cloths work - but you might want to remove some of the silicon first, the new cloths have too much in them. Otherwise, they seem to work fine on my tapes when needed. I have not noticed any buildup on the head or in the gap. Bill