The code below is giving me a string for "HashedResult" which ends with a "=" or "= =". Searches inform me that this is padding. What do I need to do specifically to get a full string without the padding? I want to append this SHA512 string to a random salt string so that I can use for password purposes. Seems to me I am giving away some secrecy if it is obvious how much of the total string is the password hash by the "= =" in the middle of my string. I could do something to get rid of the last 2-3 characters - but is there something that I am supposed to do to avoid the need of the padding in the first place?

Code:
private void Btn_Login_Click(object sender, EventArgs e)
    {
           string userPassword = Txt_Password.Text;
           var hashedResult = Hash.HashThis(userPassword);
           MessageBox.Show(hashedResult);
    }

    class Hash
    {   
       public static string HashThis(string StrText)
       {
          {
             var UTF8EncodedBytesOfStrText = System.Text.Encoding.UTF8.GetBytes(StrText);
             using (var HASH = System.Security.Cryptography.SHA512.Create())
             {
                var hashedUTF8EncodedBytesOfStrText = HASH.ComputeHash(UTF8EncodedBytesOfStrText);
                return System.Convert.ToBase64String(hashedUTF8EncodedBytesOfStrText);
             }
          }
       }