Dirt and Mold and Palmitic Acid, Oh My! - A Handy Guide

As with most objects that exist throughout the decades, physical media is no stranger to the dangers of deterioration. Tapes and discs that have been subjected to poor storage conditions are at risk of becoming dirty or moldy, and both of these problems can render media useless. When an archive receives dirty or moldy materials, the first step is to make the distinction of whether a material is dirty or moldy. After this, the archivist can proceed with cleaning the object.


When a disc or tape is dirty, it is typically coated in an external, inorganic material (i.e. dust, dirt, etc.) that must be cleaned up before transfer. If a material goes through the transfer process without being cleaned, it could potentially lead to damaging the object and the machines used to transfer the object. For example, if you were to play a dusty record on a turntable, you run the risk of dust scratching the record, destroying the stylus, and making the recording sound awful.

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So what is mold? From an archival standpoint, The Preservation Self-Assessment Program defines mold as, “Fungus that grows on polymer or organic materials exposed to high humidity; causes material degradation, and in most accelerated cases, irreversibly damaging.”  Determining whether a contaminant is mold can be as simple as using your nose. Mold typically gives off a musty odor, which makes sense because mold is generated by materials being stored in damp areas. The archivist can also determine whether or not a material is moldy by looking at the way contaminants appear on a reel. As seen in the image above, the mold spores appear in a more organic pattern on the reel; the mold grows in contained circles that radiate outwards. Unlike dirt, mold can present a serious health risk, and so it is of the utmost importance that you wear a mask and gloves when handling moldy materials.


Different from both dirt and mold contaminants is the presence of palmitic acid. Palmitic acid is a fatty acid typically associated with fruits, meats and cheeses; however, if you touch shellac discs with your bare hands, the fatty acids on your fingertips can cause palmitic acid to form on a disc, and it will look more like a filmy white substance (see above image). To avoid this problem, do not touch disks without gloves on. Cleaning palmitic acid off of discs should not be an issue so long as the lacquer is not peeling off of the disc!


Cleaning moldy tapes or dirty discs requires a host of different methods and machinery. To clean records we use a Keith Monks Record Cleaning Machine - pictured above. Using the Keith Monks Machine ensures that records stay safe throughout the cleaning process; because the machine only uses water, a distilled solution, and a vacuum, there is little risk that disks will get scratched or damaged during the cleaning process. The distilled water solution breaks down grime and the vacuum sucks it away. Because the client materials are the priority, this is an optimal method for dirt and dust cleaning.


The process for cleaning mold off of tapes requires the same level of care and preparation, just different machinery. At George Blood Audio, we will vacuum the mold off of tapes and then use a Studer A-810 machine to run the tapes. While the tape is running, whoever cleans the tapes will pinch the tape with  a Pelon or Tyvek tech wipe; this cleans the tape before it gets to other parts of the machinery. If it did get to the machinery, the mold could be transferred to the Studer and render other materials moldy in the future. 

Identifying the problem early on is the first step in ensuring that your materials stay safe and get cleaned in the preservation process.