How do I prevent OS X 10.8 from autoconnecting to a specific wireless network? I have two wireless networks at home. I want my Mac to autoconnect to one of them, but not the other. However, I do not want to remove the other network from my preferred list, since I want to keep the SSID/password saved for when I do need to connect to it. I've listed the network that I want to connect to at the very top of my preferred list, but my Mac still chooses to connect to the other network about 50% of the time. Is there any way to prevent it from connecting to that network while still keeping that network's credentials saved?
From another answer: How to disable automatic wifi connection?


  The only way to stop from automatically joining a preferred or known wifi network, is to not store the password for that network and type it in each time without clicking the "save password" button.


If you have a network remembered, and the credentials stored, there does not appear to be a way to prevent the system from trying to connect to it on sight.

Another answer with a somewhat related conclusion that may shed more light on the way the wifi autoconnect works: Prevent my Mac from connecting to an unsecure Wi-Fi network?