CLEANING SHELLAC RECORDS IN THE DIT CONSERVATORY LIBRARY

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library

This post by Sharon Hoefig, DIT Library was placed second in the CONUL Training and Development Library Assistant Blog Award 2018. 

Towards the end of 2016, the DIT Conservatory Library undertook a project to clean and rehouse a large collection of Shellac (78 RPM) records and their corresponding sleeves. This undertaking was part of a larger project to conserve, catalogue, digitise and make accessible the historical shellac recordings of the Caruana Gramophone Collection. The Caruana Gramophone Collection consists of a near-complete run of the bound Gramophone magazine and a collection of 10-inch and 12-inch records collected by Frank Caruana to correspond with the magazines. A numerical sequence, devised by Mr. Caruana links each of the records to the relevant magazine and many of the sleeves have also had cut-outs of reviews or photos of the performers from other publications affixed to them. As most 78s were issued in relatively plain paper sleeves with no accompanying information, these additions make the sleeves in this collection particularly interesting and as worth conserving as the records themselves. We had never cleaned 78s before and so the task was a learning experience which proved enlightening, interesting and … dirty.

What is shellac?

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library
Images of lac beetle taken from Maxwell-Lefroy, H. (Harold). Indian Insect Life : a Manual of the Insects of the Plains . W. Thacker & Co., 1909. Available at https://archive.org/details/indianinsectlife00maxw  

Before describing the cleaning process, it’s worth answering this question as whenever we mention the project, this the first question asked. Shellac is a resin produced by the female lac bug on trees in India and Thailand and from the late 1800s until the advent of vinyl, it was used to produce the majority of gramophone records. In fact, in the 1930s it was estimated that half of all shellac used went into the manufacture of gramophone records. Shellac records are rigid and brittle. They don’t flex like vinyl, they break and chip easily and the grooves are susceptible to groove wear through surface contamination.

Why clean a shellac record?

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library

Our shellac records were certainly suffering from surface contamination. Most of the records were housed in standard open-ended sleeves and had gathered A LOT of dust over their many years. As well as accumulating dust and dirt, shellac also suffers from a gradual embrittlement over time. The embrittlement causes fine particles to be shed from the disc after each playback.The dust, dirt and shellac particles become trapped in the grooves causing the stylus to jump and skip during playback and scratching and wearing the grooves, effectively deleting the information they contain. The importance of removing this material is therefore clear.

How do you clean a shellac record?

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library

Removing material trapped between the grooves is tricky. A dry brush will only remove dirt sitting on the top and it may even make matters worse by moving that dirt into the grooves. Residue water may cause swelling or leave behind particles floating within it. Fortunately, we were able to borrow a Keith Monks machine from RTE. The Keith Monks record cleaner was developed in the 1960s for BBC engineers and they are still used in the BBC record libraries today. The machine consists of a top deck with a turntable, 2 brush blocks and a vacuum arm. The internal components include the motor, vacuum pump and fluid dispensing system. The machine looks more complicated to use than it actually is but it did take us a few attempts on some old practice records to get it right. 

Our work process

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library

We had 600 records to get through within a limited time frame. After a bit of trial and error the following work process proved most efficient for us: 

1. Dusting. We used a dry brush to brush dust from the record label and a microfiber cloth to gently clean it. 
2. Wetting. The record was then placed on the machine, the brush lowered into place and water pumped through it. The machine was then turned on. The record turned on the turntable while the wet brushes cleaned it. 
3. Drying. The suction arm was then moved into place and the nozzle positioned on the record just outside the label. The machine was set to DRY and this time as it turned, the nozzle vacuumed up the remaining dirt and water. 
4. Cleaning the sleeves. While the record was drying, we used vulcanised latex sponges to gently clean the sleeve and a dry brush afterwards to remove any crumbs. 
5. Re-housing. The clean record was then placed in a custom-made archival folder and stored in an archival box. A piece of archival card was placed inside the sleeve and the sleeve was then placed in a mylar pocket and stored in an archival box. 

Repeat x 599

Rewarding

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library

The work was dirty and at times a little monotonous but it was also rewarding. The rewards are summed up in these before and after images. The middle photo is of the jar of vacuumed up dirt and water from the Keith Monks machine!

i: This estimate was published in The Mail (Adelaide, SA : 1912-1954) in 1937. The article is available online on the National Library of Australia website. https://trove.nla.gov.au/newspaper/article/55073762# 

ii:  https://cool.conservation-us.org/byauth/st-laurent/care.html 

All photographs are author’s own and © 2016 of Sharon Hoefig and DIT Conservatory Library. Images of lac beetle taken from Maxwell-Lefroy, H. (Harold). Indian Insect Life : a Manual of the Insects of the Plains . W. Thacker & Co., 1909. Available at https://archive.org/details/indianinsectlife00maxw