You didn't say what resistance your coils were, but from my experience 10-12 watts is just barely enough power for the nichrome 1.5ohm coils. Any lower resistance than that and you should definitely be using higher wattages.
If you're using the 1.5ohm coils then there may be a problem with the wick in that specific coil. I've had a couple of SSOCC heads that tended to let a LOT more
juice through the wick than the norm, and would constantly spit and flood. If you've got a different head you can switch to I would try that, if not you could try taking a paperclip and going in to the coil from the top chimney hole try to press the cotton down slightly directly above the juice holes. That may mash the wicking down a little and restrict the juice flow enough that it stops flooding.
Don't mash the wick down a lot, just a tiny little amount and then test the results. You don't want the top loop of the coil to be left completely exposed with no wick around it.