@ianrauk is technically correct that it needs a zero % Oxygen atmosphere to weld. But do so do most welding processes. Technically correct is the best correct
To weld it you need someone who's a kick arse weldor with a good tig welder and 99.999% pure argon. Tig welding any metal needs argon as a protective gas (almost, but we don't need to consider using Helium). This gas shield keeps the tungsten tip cooler them the metal and shields the weld pool therefore stoping the weld pool becoming contaminated with Oxygen. When welding Titanium it wouldn't be unusual to use an airtight box to weld in after flooding that with Argon.
If it's welded "in the open" It'll have subsidiary Argon introduced at the back of the weld.
The problem is that the argon gas can be blown away from the welding process far easier then say MIG or ARC. This is why you'll see ARC welding used outdoors etc. Someone walking past will affect the quality of the weld.
Finding the right person is likely harder to find then the process it's self. I have no idea as to the cost. At least €40's worth of gas even before the welder is turned on.