I have a fully delaminated lacquer (aka transcription disc). The laminate separated from the aluminum substrate long ago. Miraculously, it delaminated in one complete piece, no cracks or missing pieces. It's an audiodisc recording blank, if that matters. The laminate is hard and shaped like a combination of a potato chip and a toroid (aka "donut"). Unplayable under any circumstances. I'm not even sure that future technology like LBNL's IRENE could deal with such a deformed surface. So how to get such a sound recording to lay flat? Especially if it is hard and brittle? I wanted to run some thoughts and questions by the list related to softening of nitrocellulose laminates... Clearly the plasticizer is what makes the laminate soft for cutting grooves to begin with. As the plasticizer leaches out of the laminate, the laminate shrinks and hardens, which in the worst case leads to delamination and cracking. Those mechanisms are reasonably well understood and accepted. The question, then, is how to "replasticize" the laminate? Looking to the moving image (film) community, they will soften cellulose acetate (not cellulose nitrate) using synthetic camphor. They do this with film by placing a block of the camphor in a sealed container with the film for a number of weeks. Doing some quick research on camphor, I found that synthetic camphor is actually the plasticizer in celluloid (aka cellulose nitrate, the same material in a lacquer). The next question: was camphor ever a plasticizer component in lacquer discs? Has anyone ever tried to soften a lacquer using synthetic camphor? After yet more research, I learned that camphor is derived from turpentine oil. I'm not about to put turpentine oil on a lacquer disc surface, but it does beg the question if turpentine oil might help rejuvenate a lacquer's flexibility. More importantly, there are known plasticizers in the lacquer laminate, such as castor oil. This is why lacquer discs suffer from palmitic acid and stearic acid formation. So is castor oil yet another potential path for rejuvenating a lacquer's flexibility? There being more questions than answers, here's a quick summary of the above questions in one place: 1. How to "replasticize" the laminate? (the big question) 2. Has anyone successfully softened a brittle and deformed lacquer surface? (re-phrasing of the first question) 3. Is synthetic camphor a plasticizer used in lacquer discs? 4. Has anyone tried to soften a brittle and deformed lacquer surface using synthetic camphor? 5. Has anyone tried to soften a brittle and deformed lacquer surface using turpentine oil? 6. Has anyone tried to soften a brittle and deformed lacquer surface using castor oil? One could imagine that such a replasticizing process might extend the storage life of a lacquer that is awaiting digitization/preservation. Although the prospects are poor for revitalizing this particular fully delaminated, brittle and badly deformed disc, I'm still holding out some hope that there may be some non-destructive way to breathe just enough life back into this sound recording to allow it to be preserved. Eric Jacobs The Audio Archive, Inc. tel: 408.221.2128 fax: 408.549.9867 mailto:[log in to unmask] http://www.TheAudioArchive.com Disc and Tape Audio Transfer Services and Preservation Consulting