baking tapes

I was able to find a reference this weekend to baking tapes to reduce binder sticking http://www.unesco.org/webworld/ramp/html/r9704e/r9704e11.htm Recovery Recovery of deteriorated tape and/or signal is an intricate process: what works on one problem may well destroy, or at least exacerbate a seemingly similar problem. Sticky tape can be caused by either binder breakdown, lubricant loss and exuding, or problems with the backing. Don't assume that all problems are the same just because they create similar complications. When carrying out any actions that might reasonably be irreversible - such as baking, or chemical treatments, or buffing the tape - be sure that you are treating the correct 'illness' and are not destroying the very thing you are trying to save. * Baking One of the methods used to temporarily improve binder problems, allowing sticky tapes to be played. The information from Ampex - the developer of the tape-baking procedure - on how long and at what temperature to bake has been variously quoted at several conditions. I checked with Quantegy/Ampex for this paper and they tell me that their recommendations are to a) leave the flanges on the hubs/reels, b) use a high- quality convection type oven or an environmental chamber, and c) bake a sticky tape at 113EF/45EC to 131EF /55EC for up to 36 hours (no R/H given) will sufficiently firm up the binder so that the tape can be played. For 1/4" audio tape, baking for 6 to 8 hours is normally adequate; the longer baking times are for wider tape widths, such as 2" video or audio multi-track masters. Quantegy/Ampex warn, however, that the effect of the treatment is temporary, and it is recommended that the tape be copied within one to two weeks. Although some report having 20-or-more successful 'bakes', there is no published or documented information on how many times a tape can be baked, cycling back and forth between the sticky-firm-sticky succession before it fails completely or before the signal is distorted or altered beyond use. Care should be taken that the temperature is well controlled. One of the specific questions raised is about the potential affect of increased print-through from the baking process. There have been no reports of significant problems, but one source recommends lowering the heat (for example, from 55EC to 45EC) and extending the baking time if there is concern. Regardless of the time and temperature selected, do NOT, I repeat NOT, rewind the tape before baking as this will almost certainly increase print-through problems, according to Quantegy/Ampex. Specifically, unless there is absolutely no other option, the hair-dryer-in-a-box solution does not give adequate environmental controls and is not a recommended solution. Regardless of the sophistication of the oven used, be sure and allow the tape to re-acclimatise before handling it, much less playing. * Environmental conditioning/staging Some have reported notable success with environmental conditioning/staging tape instead of either baking or treatment with chemicals. If time allows, try staging sticky tape at 40EF/4.4EC and 20- to-25% RH (the environment that is being considered for long term storage by a number of the collections represented here today) for several weeks to several months before undertaking more aggressive measures. * Chemical treatments, including addition or replacement of lubricants, is another process that has been developed to recover tape with sticky oxide or loss of lubricants. Like baking, it should be used with the greatest of care. The only such processes known to me are proprietary and have not been made available for public use in any detail. * Cleaning In general, tape cleaning should follow the same basic premise as for any other delicate item: use ONLY as much effort and force as is absolutely necessary. To do even that will probably shorten the life expectancy of the tape; to do more will probably actively destroy it. In general, clean with soft, lint-free cloth, such as 3M's Pellon or 3M's #610 Tape Cleaning Fabric. Use moisture and chemicals sparingly, and only after testing on disposable tapes. Buffing/scraping tape is generally rejected by all with whom I have spoken, unless all other efforts have failed.