A method of forming a dissolvable part of amorphous borate includes: preparing a mixture comprising one or more boron compounds and one or more alkali compounds, at least one of the one or more boron compounds and the one or more alkali compounds being hydrous; heating the mixture to a melting temperature for a predetermined time to melt the mixture and release water from the mixture to form an anhydrous boron compound that is moldable, wherein the amount of alkali compound being selected to achieve an alkali oxide content of between about 10 to 25%; with the anhydrous boron compound at a molding temperature, molding the anhydrous boron compound in a mold; and cooling the anhydrous boron compound to form a solid.