GB1044544A - Stainless steel cooking vessel - Google Patents

Abstract

To avoid burning at hot spots the outer surface of the base 1 of a stainless steel cooking vessel is coated with a layer 5 consisting of an enamel mass containing a metal powder of high heat conductivity, e.g. aluminium or alloy thereof, copper or brass. More than one metal powder may be present. An enamel mixture consisting of 20 parts by weight, each, of feldspar, quartz flour and soda and 40 parts by weight of dehydrated borax is melted and granulated in water and 100 parts by weight of <PICT:1044544/C1/1> <PICT:1044544/C1/2> the enamel mixture with 12 parts of clay, 3 parts each of cobalt oxide and dehydrated borax and 45-50 parts of water is ground to pass through a 3600 mesh screen. The metal powder, of grain size .1 to .25 mm., is mixed with the enamel slurry in proportions adjusted to give the properties desired, e.g. 100 c.c. of enamel slurry with 500 grammes of aluminium powder, maintained in suspension by the addition of a small quantity of cold-saturated sodium nitrate solution, is applied, e.g. by spraying to the base 1 which has been degreased, sand-blasted and annealed by oxidation at 800 DEG C. The enamel coating is dried and stoved at 880 DEG C. In a modification, shown in Fig. 4, a basic enamel layer 6 is burned on the base and a mixture or suspension of metal powder in clay is sprayed on and stoved to provide layers 51, 511 which are increasingly rich in metal towards the outside, the layer 511 being almost entirely of metal and polished by a rotating wire brush. In a further modification the metal powder is sprayed dry or in suspension on to an enamel layer in moist state and dried and stoved.