or try,
IntPtr i = new IntPtr();
i = gl.NewQuadric();
gl.QuadricNormals(i, OpenGL.GL_SMOOTH);
gl.Cylinder(i, 0, 2, 8, 120, 16);
IntPtr i = new IntPtr();
i = gl.NewQuadric();
gl.QuadricNormals(i, OpenGL.GL_SMOOTH);
gl.Cylinder(i, 0, 2, 8, 120, 16);