Recycling old router for guest network ?

[jonjongx]

I would like to reuse one of my old routers to make a guest/second wireless network for family members that visit to use and for when I am working on computer to limit windows updates from hogging up the whole internet .
I plane on setting it up on a different SSID and wireless channel from main router .
Main Router IP 192.168.2.1

Would I have to have my main router give a static IP address to the second router like 192.168.2.5 and use QoS to limit it to something like a max of 80% of my connection speed and have the second router use a IP address like 192.168.3.1 to give out IP address or would I have to use a different setup for my goal ?

[Lantis]

That sounds like the way I would do it.