Hobbylinc #HLC119. INSTA-FLEX flexible thin CA is ideal for many applications, including the installation of CA hinges. When cured, INSTA-FLEX does not turn brittle and remains clear, even if accelerated with INSTA-SET. It has superior shock resistance. Although not as thin in consistency as INSTA-CURE, INSTA-FLEX still has good penetrating qualities and its application can be easier to control. .