I bought a great Purple / Pink Grande off CL for $20, it was bought for Christmas and not used. It is so brilliant, and has OK flow from time to time, but I noticed has two springs. My earlier Grande from 5 years ago just has one. The outer one doesn't allow the lava to go inside the springs, maybe only a two inch section on one side. The small one it does through fine, but the heat keeps putting bubbles going up every 5 seconds and and these marble sized bubbles passing up through the wax is what I would say drives the flow, then after while you get clusters of bubbles at top and one huge heavy ball of wax floating around the bottom. Eventually there is no flow and just a huge bowling ball size orb of wax hoovering about an inch off the bottom, not touching anything. I have tried it in my Black Giant Base where the bulb sits closer to the bottom (but after reading previous posts about the globes cracking I am scared to keep doing). By the way I am using a 100 watt regular (not reflector) bulb.
I tried spinning while warm to get all the lava into the springs. Just makes more bubbles and wax sticking to spring lasts maybe 5 minutes.
Also tried while warm SLOWLY turning the globe on it's side to get the spring to flip over and back into the wax, again the lava only sticks for a few minutes.
Any suggestions, my last resort is opening to do surgery, if so what steps to take. My guess is cleaning the spring with soapy water, drying, then dipping in wax while warm?

