Kitchen Small Electric Appliances - Fixing blade of fan

I have a 20" box fan that has developed a crack in one of the plastic blades. The very tip of the crack looks like a small piece is actually missing from the blade, and then the crack is about 1.5" long. I can remove the front grill, but do you have a suggestion of what I could use to fix the blade that wouldn't interfere with the fan's movement? I only use the fan on low and it hasn't been used that much. I thought perhaps a small piece of duct tape or electrical tape on the back of the fan blade would secure it from breaking further, but I don't know if this added weight to the blade will hurt the fan's ability to spin properly. I am not sure if super glue would hold as the fan spins. Thoughts on how I could fix this? Thanks!

It can't be fixed. Any glue or epoxy would affect blade balance and possibly cause vibration. The fix probably would give way any way perhaps throwing pieces beyond the fan if the grill broke. Blades them self are proprietary and probably not available. Of course given these fans sell for less then $20 it makes no sense to try.