Almost every article you read about high purity welding applications, like welding titanium, mentions how important a clean welding environment is—from how you store your rod to how you prep your metal and reduce the opportunity for contaminants, including oxygen, to enter your weld zone. But rarely is the choice of gas and water hose for your TIG torch mentioned.
Rubber hoses for your TIG torch
At Arc-Zone we almost always recommend rubber hoses. They are more flexible and easier to handle and don’t melt when in accidental contact with a piece of hot metal. But when welding titanium you may want to consider the vinyl hose set up.
We first became aware of this when back in 2008 when one of our customers, a manufacturer of high-end TIG welded aerospace parts called and asked for a custom-built TIG torch with vinyl (or as our Joe Welder likes to call them “plastic”) hoses. Aside from being stiff and awkward, the “plastic” hoses are so much more susceptible to damage in shop than the rubber hoses…
Vinyl Hoses for your TIG Torch when welding titanium?
It turns out that rubber hoses, while indeed are more robust, in certain conditions, can absorb moisture from the atmosphere and cause problems when welding reactive metals like titanium, molybdenum, nickel-based and aluminum based alloys as well as non-reactive metals like stainless steel.
The American Welding Journal even covered this in a December 2007 article, “The Welding of Titanium Alloys:”
“Gas hoses should be non-porous, flexible, and made only of polytetrafluoroethylene (PTFE), polypropylene (PP), or high density polyethylene (HDPE). FEP-lined Tygon(R) has superior resistance to moisture absorption and is recommended. Rubber hoses absorb moisture and should never be used in any titanium welding operation.” (page 43)
If you’re an AWS member you can login at the AWS.org website and check it out yourself.
Best TIG Torch for High Purity Welding applications?
Working hand-in-hand with this customer Jim Watson (Arc-Zone.com’s head honcho aka Joe Welder) developed a complete TIG Torch package optimized for high purity welding… in fact since 2008 that aerospace customer’s business has boomed and they are now outfitting 12 new weld stations with the Arc-Zone Hi Purity TIG Torch assembly. You can read details over on the JoeWelder.com later this week.
And for more information about welding titanium, here’s a good publication from the Titanium Metals Corporation, “Titanium design and fabrication handbook for industrial applications” (pdf)