To re-enamel a hot and cold water bath, specially prepared enamel paints are used. Thoroughly clean the surfaces of the bath with petroleum and well scour rusty places with emery cloth; when clean and dry, rub in a paste of lime and petroleum; wipe this off before painting. Apply two thin coats of paint; allow the first coat to dry hard before applying the second. Pale green or eau-de-nil are good tints.