I have a 72 inch QQ Yak that the styrofoam sides of the fuse are breaking. I would like to know what type of glues/techniques are used for styrofoam repair. The styrofoam has a horizontal crack and no longer adheres to the balsa fuse. see pic

if it is eps foam elmers white glu or an aliphatic resin glue or epoxy will work.just squeeze the glue into the crack and clamp by wrapping masking tape around the area.

Poly glues (gorilla glue, elmers poly glue) are excellent for foam and balsa. They will expand to fill the gap, and will creep into the pores. They must be clamped to prevent the expansion from warping the fuselage.

Brad

Confused on the part of clamping to prevent warping of fuselage. Please explain how this works.

Poly glues expand as they cure, and they use moisture to cure. The more moisture, the more expansion. The hotter the ambient air temperature, the faster they cure.