Annoying floodlights?

Question:hey. i just installed floodlights so they would shine on my pool. i bought blue and green bulbs and i put them in but when i get them positioned on the pool where i want them and i tighten the hand screw that makes them move, the weight of the bulbs makes them slide down and its getting annoying. there are like these silver nuts by where the two lights themselves screw into the plastic on the box, can i loosen or tighten these to make the mights stay where i want them, cuz the hand turned screw thing with the gears doesnt put them where i want. ahh god help.

Answers:
use metal bonding glue