Sikaflex-268, Powercure 600 ml Tube, 14/Case. Assembly & Glazing Adhesive and Sealant for Rail Applications with Acceleration Option. Sikaflex-268 can be applied at temperatures ranging between 5 °C and 40 °C (climate and product) but changes in reactivity and application properties have to be taken into consideration. The optimum temperature for substrate and sealant is between 15 °C and 25 °C.