StringWriter com encoding Windows-1252 http://stackoverflow.com/questions/427725/how-to-put-an-encoding-attribute-to-xml-other-that-utf-16-with-xmlwriter

StringWriterWindows1252

using System.IO;
using System.Text;

public sealed class StringWriterEncoded : StringWriter
{
    public override Encoding Encoding
    {
        get { return System.Text.Encoding.GetEncoding("Windows-1252"); }
    }
}