Shellac varnish. A good shine of shellac varnishes can be obtained by using dewaxed shellac for their preparation. Such a shellac can be obtained as follows: dissolve 5 g of sodium carbonate v 95 cm3 of water, add 10 g of shellac and cook until, when the released wax forms a ball on the surface of the liquid. After cooling, the wax is removed and the shellac is precipitated by the slow addition of diluted 1:10 hydrochloric acid to the moment, when the added amount of acid does not cause the solution to rush. Rinse the separated shellac several times with water and dry it.
Varnish can be obtained in one of the following ways:
• 30 g dewaxed shellac i 1 Dissolve g of castor oil in 100 cm3 denatured;
• 10 g dewaxed shellac i 2 Dissolve g of camphor oil in 90 cm3 denatured.
The water contained in the denatured alcohol also causes a slight turbidity of the varnish coat, so it is better to use dehydrated denatured alcohol.