You're often going to need to ask for volunteers to help you build up the community.
Most community leaders go about this in entirely the wrong way. They ask for volunteers. The volunteers who respond usually won't have any of the associated requirements, background, or history. Why? They weren't bothered to do it in the normal interaction of the community. Not many people will take on a job that the majority never bothered to do. And very few will do it with pride.
Don't ask for volunteers. Be proactive and seek them out. They exist on your community, they've already participated or contributed, and many just need that extra nudge to be your next superuser.