Enamels and enamelling; an introduction to the preparation and ...

COMPOSITION OF MASSES FOR GROUND ENAMELS. 125
Ground Mass ivith Magnesium Sulphate, No. 2 (for Iron Utensils).
Flint meal 30 parts.
Borax 10
Magnesia 4 ,,
Magnesium sulphate 2-25 ,,
Soda 1-75
fused together and ground with
Flint meal . . . .18 per cent, of weight of mass taken.
.... 18
The foregoing recipes are used in the largest works and
suffice perfectly for all purposes in the enamelling of cooking
utensils, boiler tubes, etc. In order, however, to afford makers
a means of rectifying certain imperfections manifested by
enamels a brief notice of these and their remedies will now
be given.
1. Ground mass readily chips off from the foundation.
Remedy : Add magnesium sulphate.
2. Mass difficult to distribute on the metal and holds
badly. Remedy : Add a little magnesia, excess being avoided
as it makes the enamel too refractory.
3. Mass too hard. Remedy
potash; or, better still, both.
: Add a little lead oxide or
4. Mass too fusible. Remedy : Increase proportion of clay
and flint meal when grinding the fused mass.
Percentage Composition of
Certain Ground Masses.
(Analysed by Vogelsang.)