Two-part Epoxy Repair Technique Two-part Epoxy Repair Technique Load-Transfer Filler Epoxy Application Fix Stix® Mixing and Application Load-Transfer Filler Epoxy Application The best practices for hand-mixing the two-part epoxy and applying to surface voids and defects are demonstrated in a step-by-step guide. Fix Stix® Mixing and Application The best practices for hand-mixing the two-part epoxy putty stick are demonstrated in a step-by-step guide. Watch this video to see how.