Hi Larry, Hi Al,Tim, MDG, and Allen whom I know is always a sponge to this sort of stuff!!! Weldcome Plasmahead2!!! Good to see everyone is well :) ;)
Been real busy as you well know being a fellow educator and all... Anywho, if you don't want to have a spare cylinder of argon, then get yourself one of those plastic turkey basting bags, and weld the Ti in there!!! It'll do the trick in a pinch and for what you're doing, the excess oxidation will not be too critical. :) :) :)
One thing you need to understand is that the excessive oxidation due to improper shielding of the root side of the weld will increase the amount of interstitials (look it up if you want) but, it simply means metallurgically speaking of course - that the nonmetallic particles on an atomic scale, tends to overcrowd the crystal lattice arrangement (okay, it's a little bit more complicated than that but, I'm trying my best to keep it simple so, bear with me :)) in such a way that the grain boundries start to separate because of the increased "slip planes" due to the overcrowding of the interstitials - otherwise referred to sometimes as "excess garbage' within the crystal lattices, and are not as strong as the base metal was before the introduction of heat, and hypothetically speaking of course - since only a shielding gas was used that only protected the molten metal pool from 'oxidation" or, better described as "atmospheric contamination" at the face of the weld pool as opposed to having up to 3 layers of protection such as the first being an inert atmosphere or if not possible, both a shielding, and trailing gas shield along with a backing gas shield or once again, a totally inert atmosphere, then the addition of a slightly different grade of Ti would be added to coalesce the two members together in order to fuse with added strength, or if you're just autogenously welding the two members (components that make up the assembly - otherwise known as parts) together without the addition of filler metal, then it really doesn't matter whether or not you use a backing gas or inert atmosphere (I suggest a turkey basting bag if you're going to do this on the "Cheap!!!") because, you'll be just weakening the adjacent members of Ti anyway!!!
It comes down to this simply put... If you introduce heat to any reactive metal, whether it be CP (Commercially Pure) grade Ti or Zirconium for that matter, and you do not properly shield it in one way or another, and add the matching filler metal for that metal - there's an excellent bet that the fused metal will be weaker than the base or parent metal was originally, because all of those extra, overcrowding oxygen, and nitrogen atoms that are part of the interstitial family of metallic elements or compounds will weaken the crystal lattices, and therefore weaken the grain boundries or grains themselves!!! In other words too much oxygen, nitrogen, carbon, and other "interstitials" equal unecessary GARBAGE that weakens the weld - PERIOD!!! On the other hand, the proper amount of interstitials used in a metallurgical matrix will potentially increase some of the desired mechanical properties of certain metals however, strict controls must be adhered to in order to achieve this :) :) ;) Gotta go!!! Heading down to the "Burgh" from Wellsville!!!
Btw Larry, Al, and Allen, I'm the new Senior Year Welding Instructor at Alfred State Technical College which is part of the State of New York University system, otherwise known as SUNY, and I've got to get the last of my stuff back up here to finish my relocation to Olean, NY so, forgive me for not participating here as much as I normally did in the past!!! Once I get settled in, I'll be frequenting my "Second" home here again very soon!!! I also played around with some Ti to see what colors I could get, and ended up making a "Peacock" out of CP grade 2 Ti which when I find the pics, I'll post it up here. :) ;)
Respectfully,
Henry