Technical Library

TROPICS VI: Mould Gallery

Entire Contents Copyright © 2010 CBH
Next 1K gifBack 1K gif


There are over 100,000 known species of fungi, and probably twice as many remain to be identified. Microscopic mould spores are circulating everywhere in the air, only waiting for the opportunity to land and germinate in ideal conditions. A few main types of mould seem to manifest themselves on keyboard instruments under adverse climatic conditions. Each variety exhibits a propensity to appear on its favorite substrate. The following photographs will help you identify the main troublemakers. Later, we can examine what mould needs to thrive, and how to make things more difficult for it:

  • A general blotchy dullness easily detected on the case interior, exterior or stand, spreading outwards. This type of mould seems to prefer oil-based paints or varnishes.

Case exterior mould

Harpsichord case mould 8K jpeg

  • Brown blotchy spots favoring the coniferous wood of the soundboard or wrestplank veneer beginning about 3mm in diameter, and spreading outwards, similar in appearance to the mould which causes “foxing” on old books and postage stamps.

“Foxing” on wrestplank veneer

Foxing soundboard mould 20K jpeg

  • Furry grey-green mould favoring extraordinarily wet wood as seen in water-damaged instruments.

Mould growth on water-damaged keyboard

Mould on water-damaged keyboard16K jpeg

  • White frosty mould which seems to feed off the yummy medium (gum arabic or egg yolk) of the soundboard painting, appearing to prefer less toxic colors.

Frosty mould on soundboard arabesque
Hong Kong

Soundboard painting mould 19K jpeg

  • A white ringworm-like fungus which attacks starch-based glues often used for attaching printed Flemish case papers, and spreads out in circles of increasing diameter destroying the paper.

Mould on Flemish papers
Hong Kong

Flemish paper mould 6 jpeg

  • This white mould complex of fine hairs is fruiting after growing undisturbed in a dark and damp place.

Hairy soundboard mould

Soundboard mould 15K jpeg

  • A dull orange fungus which prefers a rough surface like a harpsichord bottom with only a single thin sealing coat of paint.

Mould on harpsichord bottom
Hong Kong

Harpsichord bottom mould 18K jpeg

  • A powdery green fungus, not unlike that which appears on oranges can sometimes be seen on instrument bottoms. This is most usually a type of mould in a dormant phase, just waiting for the right conditions to flourish. It can often be successfully removed dry.

Tropics index:

CBH Icon 1K gif Technical Library overview
CBH Icon 1K gif Harpsichords Australia Home Page