Shrinkage glue

Another possibility might be to use solutions of acrylic polymer dissolved in acrylic monomer and to harden the glue in situ by heat-activated, free-radical-initiated polymerization. Such a glue should have acceptable shrinkage properties and, if the components are properly chosen, could remain fairly tough. Further, if non-cross-linking components are used, it should be a reversible system. 

These materials are cut out as various parts, which are then assembled and stuck together with hot melt glue, thus creating the final shape of the casting, also taking into consideration any possible shrinkage of the metal. 

The rapid drying of lumber is also made use of in the furniture industry, in which precut furniture parts may be dried in minutes rather than days or weeks and the shrinkage is well controlled. Dielectrics are also used to dry the glue. Golf clubs are also dried in this manner [10,11]. 

Quick setting, within a few hours at most, with neither inordinate heat generation nor excessive shrinkage. Some epoxies and other cements, such as cyanoacrylate ester (Super Glue ), which harden in only a few minutes, are recommended in circumstances where quick answers are needed. 

This class of adhesives mostly includes soluble silicates and zirconia. Silicate-based adhesives are typically modified by adding clays to reduce shrinkage, protein glues for water resistance. 

---