Pour les chimistes / For the chemists
The preparation and use of base baths for the cleaning of glassware
Base baths are normally made up from 1 litre of water and 500 g of sodium or potassium hydroxide, with enough industrial methylated spirits (IMS, Methcol) to make up to a useful depth in the bath. Alternatively, the hydroxide can be added directly to the IMS in the container, without the addition of water; it will dissolve over time. Consequently they are extremely corrosive and precautions must be taken in their preparation and handling.
1 Safety spectacles and gloves must be worn when making up a new base bath or destroying a spent solution. The gloves should be of heavy duty quality, and should be checked for splits or leaks before use. Add the potassium or sodium hydroxide to water in a flask to dissolve it. When it is completely dissolved and has cooled (considerable heat is generated in this process) add it to the IMS in the bath.
2 Good quality gloves should always be used in placing glassware in the base bath, or in removing it for rinsing.
3 Disposal of spent baths should be effected by slow addition to copious quantities of water and slow flushing down the sink, again with a large amount of water.
4 When not in use the lid should be placed on the bath. The plastic container for the base bath should be checked for damage regular intervals, and MUST be replaced if necessary.