Titanium is one of the harder things to to work with regardless of the method you are using.
Titanium cannot be soldered but can be brazed or welded, since the temperature exceeds 450 C. Titanium in the presence of any oxygen forms a tightly adherent oxide layer, which impairs joining by brazing, welding, etc.
In ideal welding titanium is brazed in an argon atmosphere, without a flux, using different types of filler metal. Field welding is possible but requires equipment and skill beyond the typical hobbyist.
There is a good description of the technology in a technical paper from Nippon Steel, one of the leading producers of titanium alloy products. Use the following link for more information: http://www.nsc.co.jp/gikai/en/contenthtml/n62/6205.pdf