This 2oz bottle of PVA glue is your basic white glue, it has a thicker viscosity andh works best on our foamies. It is only used when you glue the horizontal and vertical fuse together. The flexibility of the glue joint helps prevent the Depron from cracking on a hard impact. It does take 24 hours to dry and is not required, but it will help prolong the life of your foamie. This glue is not to be used on servo-mounts, control horns or the firewall.