I have a lot of glass bottles and jars. I want to convert them into new items of different styles and shapes. Can a glass object be molded into a new shape by melting? If yes, then how?
Yes, The general term is 'bottle slumping'. There are several images on pinterest. The glass is heated to the point that it can be shaped. Current trends are to use a Kiln, with temperatures between 500F and 1500F
I have memories from local carnivals in the 1960s and 1970 of the bottles being heated in a liquid, shaped and given as prizes or sold. I had a coke bottle for several years that was obtained from the carnival.
I wouldn't recommend it. Glass especially bottles/jars can explode when heated like that sending pieces of hot glass flying in all directions I recommend getting a good art and craft kit specifically for glass.