Het mengen van ijzerchloride uit granulaat.(Engels)
In general, the necessary mordant solution is made using crystals even though it is possible to find ready made liquid solutions. The solution is made by mixing 10 kilos (22 lb) of crystals with 3 liters (3,3 quarts) of water at 15° Centigrade (122° Fahrenheit). The solid iron perchloride is put into a plastic, rubber, sandstone, etc. recipient (never use a metal one) with an opening big enough to permit mixing the ingredients (mixing should be kept up for some 20 minutes). After cooling off weigh a sample of the liquid obtained and lower its concentration (by adding water) to 46°B. The job has to be carried out carefully since the solution obtained by the above mentioned mixture will be anywhere betwenn 50° and 48°B. Be careful in adding water because the concentration decreases very quickly. Remember to shake the mixture and make sure that it is between 18° and 20° Centigrade (64 and 68° Fahrenheit) before using the hydrometer. The solution is right when the liquid reaches the 46° mark of the hydrometer. Measuring should be done in a tall container whose thickness is proportionate to the quantity to be measured. The pasty deposit produced by this first mixing should be kept to be used in reinforcing solutions or in making new ones. Any handling of this salt should be done carefully and only when wearing rubber gloves. In fact, iron perchioride is quite caustic even though it is not as corrosive as strong acids. It will turn hands yellow and spot and attack clothes. A 46° solution of iron perchloride should be prepared in relatively large quantities since it is used for most mordant baths (as in aquatint) and in making 41°, 36°, and 33° solutions which in turn are used for complementary bitings, intaglio etching, scouring, etc. The bottles containing the various concentrations should be properly labeled.