Zunhua: Bus to Tianjin?

I am thinking of taking the bus from Chengde to Zunhua and spending a day at the Eastern Ming Tombs. I would like to go on to Tianjin. I would probably be traveling to Tianjin on a Monday or Tuesday. Does anyone know about buses to Tianjin fron Zunhua? If there is, does anyone know about how long the trip is and how often they leave.