...and every weld is a work of art.
No doubt they are. Nuclear TIG welds some of the most beautifully welded. X-rayed every step of the way, super thin wire required to be used to eliminate any porosity or contamination. I have a really good friend who welded Nuke pipe at the Shipyard for 15 years. That boy can flat weld!
To weld thin walled Ti tubing, you'll need a purge kit set up, and preferably a pulse capable TIG box. Everything has to be SUPER clean when welding Ti, and the filler wire needs to be cleaned too, and remain protected while stored. Once the wire is exposed to the heat, it needs to stay in the Argon until you're done else it will contaminate immediately.
These tricks (among many others) are what makes welding Ti so different. The color of your weld tells the tale. Without a back purge, the weld contaminates from the inside out, and that will cause failure. Might start with Stainless for practicing your tube designs and welds. You can always swap the exhaust later with a Ti welded one. Or, if it escapes you, fab one from stainless that you weld, then get a guy from work to make it from Ti for you later. Best of all worlds.
