< SURFACE PREPARATION
PREPARING & APPLYING PATINATION CHEMICALS
Chemicals for patination can usually be obtained from specialist stockholders. The chemicals are often available either as a refined compound (for dilution in a water solution), or else as a proprietory preparation (in paste or soluble form), ready for direct application to a prepared cast. A few experienced foundry technicians make their own chemical preparations from raw materials. This is usually done by dissolving selected metallic filings (iron or copper for instance) in NITRIC or similar acid solutions with a strong oxidising tendency. Preparing compounds can be potentially hazardous, and any procedure involving powerful chemicals should always be undertaken with extreme caution (see SUPPLEMENT).
The following pages describe the basic application techniques used by founders and other technicians to impart an artificial patina to metals. Many of the techniques described here are common place, though some are rather limited in use, either for reasons of practicality, cost, or the length of time taken for a satisfactory patina to develop.
COLD PATINATION >
|
