On surfaces which will become covered by a glutinous whitewash, cracks are closed up by gypsum chalky or gypsum glutinous mortars.
The gypsum chalky mortar is prepared from: Gypsum - 1 part, Chalk - 2 parts, with adding the solution of animal glue of 5 % up to necessary consistence.
The gypsum glutinous mortar is prepared: with adding the solution of animal glue to Gypsum up to necessary consistence.
At closing up of the big deep cracks in the above-named mortars is added 1 part of sand.
Cracks on surfaces which will be painted with an oil paint or enamel, are closed up by a following mortar: paint oil – 1kg, 10 % solution of animal glue – 100g, the separated chalk – up to necessary consistence.
The glue solution slowly is added in paint oil, constantly mixing. In formed emulsion is added the chalk, reaching the necessary consistence without lumps
