A face lift for the Port of Sydney
Intensive treatment for a brittle map
11 October 2011
We’ve recently been working on a Map of part of the water frontage of the Port of Sydney shewing parts of the land and wharfage vested in the Sydney Harbour Trust Commissioners. It was donated to the National Library by a former employee of the Customs Department in Sydney. The map appears to have been used as a wall-mounted copy in the Customs Department, and the colouring was presumably added at that point to highlight plans or working arrangements at the time. This map came into the collection in a relatively sorry state. It was adhered to an acidic backing board, there were numerous tears and losses and the paper was very brittle. The proposed treatment included removing the acidic backing board but completing this task without causing further losses looked a little tricky.
Due to the brittleness of the paper, turning the map upside down and removing the backing was not a viable option. We decided to put a facing on the front of the map to protect the image surface during treatment.
Detail of damage
A facing is a sacrificial sheet of tissue, or in this case Rayonshi that is adhered to the front of the item using a reversible adhesive such as methyl cellulose. This way we were able to turn the map onto its face without any fear of causing more damage as the rayonshi protected the surface and prevented any losses.
We were able to split the backing and remove the bulk of it mechanically. Once we were closer to the map we started to brush water onto the surface of the backing and using some specialist tools we scraped away the remainder of the board down to the map.
Removing the backing
Once all the backing had been taken off we wanted to remove some of the acidic products that had clearly migrated into the map.
Removing the backing
We used a steeping method for this, which is a gentle washing technique that uses the capillary action to draw out the yellow acidic products and strengthens the paper.
Blotting paper was wet out and the map was placed on top of the wet surface. We left it sitting on the blotting paper for about an hour before it was removed, we refreshed the blotters and repeated the process again.
Yellow acidic products seen on the blotter
The map still needed extra support so we prepared a lining tissue and a mixture of wheat starch paste and methylcellulose. While the map was wet we placed it face down on a sheet of mylar.
Pasting out the lining tissue
The lining tissue was brushed out onto a separate sheet of mylar with the adhesive and then it was brushed onto the map through the mylar. The mylar was removed and replaced with a sheet of reemay and flipped over onto its back. The mylar on the face was removed, as was the facing which peeled away easily. Finally we had to secure all the loose pieces that had fallen off. The map was placed between reemay and blotters, placed under weight and left to dry.
We have chosen not to continue any further treatment. There is always the option of making infills to make an item appear more visually complete. This was deemed unnecessary as this is a time consuming process and the map was going to be returned to storage The map is now in a stable condition and will last for many more years to come.