What is the effect of fuselage weight on a model glider?
Variations in aircraft weight do not affect the glide angle provided that the correct airspeed is flown. Since it is the lift over drag (L/D) ratio that determines the gliding range, weight will not affect it. 

The glide ratio is based only on the relationship of the aerodynamic forces acting on the aircraft. The only effect weight has is to vary the time the aircraft will glide for. The heavier the aircraft is, the higher the airspeed must be to obtain the same glide ratio. 

If two aircraft have the same L/D ratio but different weights and start a glide from the same altitude, the heavier aircraft gliding at a higher airspeed will arrive at the same touchdown point in a shorter time. Both aircraft will cover the same distance but the lighter one will take a longer time to do so.