An airfoil vane assembly includes a vane piece defining a first vane platform, a second vane platform, and a hollow airfoil section joining the first vane platform and the second vane platform. The first vane platform defines a collar projection therefrom. A spar piece defines a spar platform and a spar extends from the spar platform into the hollow airfoil section. The spar platform includes a radial opening defined by first and second axial faces. The radial opening is configured to receive the collar projection, and a groove in the first axial face. A seal is situated in the groove. The seal seals against the collar projection and a biasing member is configured to bias the seal towards the collar projection. A method of assembling a vane is also disclosed.