illustrator stroke outline help

Hi all.

Have been face palming my way through this. And highly likely am using the wrong terms here...

I know how to create outlines with text...so I can use pathfinder to trim.

However I have a brush stroke, one path/line/stroke, that I want to create an outline of the brush, so I can trim against a square of colour. Am I going about this the wrong way???

so simple, but so frustrating....

Face Palm.

Found it. Under expand.
Always the way, when you get to your witts end and ask for help.