How do I create a Color Mask with 2 metals with different roughness settings?

I have a material of a dagger i made with a normal, diffuse, and a color mask. on the color mask, i have masked my red channel as the blade metal, and the green channel as my hilt metal. Im trying to set different roughness settings to them but can only pass one into the rouchness node. how do i add them but keep the setting sepereate. Hope this makes sence

Hi Alberio83 -

You will want to use your color mask as an Alpha input to LERP between the two Roughness values.

Thank You

Eric Ketchum