Page 12 - HIWT Winter 2011 World of Welding

THE WORLD OF WELDING http://www.welding.org

RePaiR Of 4130 TuBinG

By Elmer Swank, Jr.
AWs CWI/CWE/CWS
Technical Instructor
Hobart Institute

QueSTiOn:

It seems a popular alloy
with the “do-it-yourself”
aviation group is 4130,
since the skeleton of a light
aircraft is made of it (or wood). I saw one of the frames
and it is definitely light stuff. Is TIG the process of choice
for repair? If so, which filler? A couple people said they
used oxyacetylene flame to do repairs. Is this good? And
while I’m asking, how about cutting this thin material?

anSWeR:

Thin wall 4130 tubing is popular for many tubular frame
applications. The 4130 material is high strength, doesn’t
bend easily, and has good weldability. Since the mid-
1940’s, gas tungsten arc welding has been the preferred
welding process. Prior to 1940, oxyacetylene was widely
used. Oxyacetylene preheats, welds, and stress relieves all
in one operation. For “oxy” the filler wire was Oxweld®32
cm or equivalent. I am not certain if that wire is even
available any more.

With gas tungsten arc welding, ER80S-B2 or ER80S-D2
is used. A preheat of 250°F is recommended, although
some people don’t preheat at all. Postweld stress relieving
is normally not needed on thin material. Cutting is mostly
mechanical, although plasma cutting will also work.

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