This week we had a cookery course during our mosaic practice. No, we didn’t prepare stone soup. But we have learned how to make a temporary adhesive for rovescio su carta, the indirect mosaic technique with which we started here at school. Although the adhesive holds the tiles firmly to the paper, the glue can be easily solved by wetting the paper back once the mosaic is glued to its permanent base.
Of course you could buy a similar compound in a store. But that would be more expensive and not half as much fun. So here’s the recipe for the sticky mass that looks a bit like peanut butter.
Recipe Colla di farina (flour glue)
Flour, water, liquid glycerol, formalin (can be replaced by cider vinegar)
Saucepan, wooden spoon
According to my teacher this recipe works by eye. For the ratio of flour:water I would say it is about 1:2, though. So if you use two cups of flour, then this is filled up with about 4 cups of water.
Preparation: Stir the flour with a little water in the pot to a creamy mass. There may not remain any lumps, but the flour should be completely dissolved in water. Now bit by bit add the rest of water according while stirring.
On the stove: Once a homogeneous liquid is formed, slowly heat the flour -water mixture on the stove at medium heat, stirring constantly. Once the mass has become something solid (about 1-2 minutes) and forms lumps, remove the pot from the stove. Continue stirring so that the clots dissolve. Add 2 teaspoons of formalin (or cider vinegar) and 2 teaspoons of liquid glycerin while stirring. Store the prepared glue in a Tupperware bowl.
The whole process must be very fast, because if the glue cooks for too long it won’t be sticky enough and the mosaic over time could come loose from the paper. So don’t leave the pot on the stove for too long and under no circumstances use a gas stove. It would heat the mass too fast. A moisty flour glue is better than a dry one because by time it will loose some moisture. Formalin or cider vinegar ensure that the glue does not get moldy. The glycerin makes the glue soft.
All information given without liability.
If you try the recipe at home tell me how it worked.