If the walls underneath are plaster, you should be able to get most of the mastic off with this scraping and chipping, but you will probably have to use an electric sander to get the rest of it off.
12.
Garinda M . Iman surveyed the sawdust-strewn floor of his one room shop in the hill country just south of here, where his workers use wooden mallets, crude chisels and electric sanders to fashion ornate tables from the giant roots of century-old mahogany trees.
13.
After the sheets are off there will still be lumps of cement or adhesive left on the walls, so chip off as much as you can, then use an electric sander to grind the rest of the lumps off ( rent a sander if you don't have one ).
