I've read a lot of tales here about cracks forming in the tanks of Vision Clear-O-Mizers (aka 'Stardust'), and when one of mine developed cracks so bad that it began to leak, the model builder in me came out, and here's how to repair the cracks:
1) Clean it with hot water, inside and out. Don't try to disassemble it because you'll just risk making the cracks worse.
2) Apply a small amount of plastic weld to the cracks. I use Ambroid ProWeld for Styrene, Butyrate, ABS, and Acrylic (Lucite or Plexiglas). The liquid is sucked into the cracks by capillary action and literally melts and 'welds' the plastic back together, unlike CA or other adhesives that simply glue the material.
3) Let it dry for about 12 hours and then wash it again, just to be safe.
4) When you cover the base with your finger and suck on the mouthpiece, if you can draw a vacuum, you've repaired all the cracks; if not, do it again.
This won't prevent new cracks from forming, but they can be easily repaired this way, and the tank should last as long as the coil. I've gone through several refills with no further leaks. Give it a try!