Isolate 2 networks through a Mac


Apr 13, 2012
Our church has two internet connections, one that the internal network accesses and one that the wireless network in the building accesses. For (obvious) security reason we need to keep the networks isolated from eachother.
On sunday's when we upload the sunday sermon video recording we caused a network lag for other computers on the network, thus the church has asked us to use the wireless network to upload the videos. We record the video on one computer, then can transfer it to a Mac that has 2 network cards.

How do we isolate the two networks from eachother without plugging and unplugging cables and have the Mac upload through the wireless network instead of the wired network?