Ah, yes, you have to clean the weld points thoroughly, and you need an argon gas shield while you're welding. But other than that, it's easy?

The reason I'm asking is that I will soon be taking a welding course myself, with the intent of starting up a new hobby. Eventually I want to build my own trike, and I want to build it out of titanium. Why titanium? Well, because virtually no-one else has a titanium trike, that's why.