The trouble with stop leak stuff is that it's meant to plug holes... Stop leak doesn't differentiate between a pinhole leak from the radiator itself or some of the small passageways within the motor.
Keep topping it off with coolant until you can replace the radiator(you mentioned it was the plastic tank)
The link asand1 posted looks like a good deal for a radiator.
Keep topping it off with coolant until you can replace the radiator(you mentioned it was the plastic tank)
The link asand1 posted looks like a good deal for a radiator.
