when inserting a plastic window vent into a glass block window, which is better-- silicone, acrylic or etc.?

i would think acrylic

Pure silicone.. more holding power and weather resistant than acrylic..Most acrylic cauls have latex w/ them so clean up can be done w/ water. Any wet area I ve never trusted a water clean up product GL

Mortar is a sturdy determination little doubt if finished wisely and sealed. i for my section want silicone although. My motives are a million is does no longer could desire to be sealed and could no longer take up moisture. 2 that's versatile and could no longer crack like mortar will. 3 it is going to final for years and not wreck down like mortar. wish this helps interior the tip the two will do the activity if finished wisely! good success Tim