Use a 5v relay to trip a 12v relay?

Other Hardware Motors, Mechanics, Power and CNC
2

Well, 2 problems - the 5V relay looks to have a 50, 56 ohm resistance? Arduino can't drive that. Need a transistor to drive that.
2nd, yeah you need a 12V source.
If you had 12V and the transistor, you wouldn't need the 5V relay.