Very strange grate replacement
Ok, I had a rope get caught in my intake. I took the grate off, cut the rope into 50 pieces, got it off, and then...
went to put the grate back on and 2 of my bolts would not screw into the embedded nuts on the rear side. I tried for 45 minutes to screw them in. I'm quite sure I never damaged the threads. I did see some hardened substance in the nuts but managed to poke at it and brush them off (don't know what the heck that was). Never got the grate screwed back on!
Anyone have a clue with the screw?!