GameObject alpha fade in SteamVR

I am brand new to Unity and have been bumbling my way through my first project. I am creating a 360 video tour. The tour has objects that I want to fade on when I activate them at a certain time in the video playback. I am having trouble with the actual fade effect. I have tried just about everything I can think of and have been through so many forums and tried whatever I could find. The closest thing I have found has been this:

  public GameObject davidInterface;
  public float timer = 1;
  public float alpha = 0;
  Renderer r;

  // Use this for initialization
  void Start()
  {
      r = davidInterface.GetComponent<Renderer>();
  }
  // Update is called once per frame
  void Update()
  {
      float lerp = Mathf.PingPong(Time.time, timer) / timer;

      alpha = Mathf.Lerp(0, 1, lerp);
      Color color = r.material.color;
      r.material.color = new Color(color.r, color.g, color.b, alpha);

  }
  }

It isn't exactly what I want, but the alpha on the material does fade in and out in the material preview during testing, but the actual object doesn't change. I am using the standard shader with rendering mode set to fade. I have tried adjusting the alpha manually during testing, but it still doesn't show up in the actual game, the alpha stays at whatever it was when I pressed play. Any ideas?