Cup Size

by Chuck
(Pearl River, La. USA)

What factors generally determine the size of the cup to be used?

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metal type--for example, titanium needs a really big argon shielded area...inconel welds better with a large cup because it keeps the hot tip of the rod shielded better. most everything except aluminum and mag welds better with bigger cups.

that being said, cost comes into play too. Mild carbon steel will look better with a large cup but that doesnt mean the weld is any better.
I use as small a cup as i can on carbon steel when I am paying for the gas.

Aluminum---too much gas dilutes the arc energy.
i like a fairly small cup with low flow of gas.


joint configuration--tight joints usually need small cups


remember to change the flow along with the cup size. if you go down to a number 4, any more than 10-12 cfh is usually too much

PIPE welding ---use the right size in order to reach the root of the pipe and still get good shielding.

good luck,

jody