5F TIG Fillet Weld Test

The video above shows a 5f TIG fillet weld test that compares walking the cup to freehand.

Both walking the cup and freehand are good techniques but sometimes there are other pipes in the way that limit your torch motion and prevent walking the cup.  That is when freehanding is good to know.

TIG Finger Quick Vids

Propping on hot aluminum 5f tube to plate weld

If you have every had to prop on aluminum, you know how quickly your knuckles start to heat up.

Propping with a TIG finger® TIG welding aluminum dog feeder

3G weld cover pass Freehand with TIG finger

Freehanding with a tig finger® lets you prop next to the weld without worrying about how hot your knuckles are.

A 5f fillet weld is a tube to plate weld where the tube axis is horizontal and the plate is vertical.

The 6g weld test is more commonly used as a hire in weld test and qualifies a welder for both groove welds and fillet welds but ...

Sometimes a 5f test is used as an option to qualify a welder for fillet welds only.

Why would you want to qualify for only fillet welds?

Well, in the case of my friend Andrew Cardin, most of the work his company does is 6010 and 7010 downhill for gas distribution piping.

But occasionally his company will send him to make a single weld for another company.

When that happens, his company has to make sure he has the proper certification for the weld...even if the weld is one simple socket weld cap.

Rather than take a time consuming 6g test for a one off socket weld (which is a fillet weld), a 5f weld test can be administered and sent to a lab for testing.

A 5f weld test is not rotated while welding and requires welding in overhead, vertical, and horizontal positions and therefore qualifies the welder for all positions but for fillet welds only.

5F tig fillet weld test

Depending on the thickness of plate and pipe, more than one pass might be required. 

The welding procedure should specify the number of passes or at least the fillet weld size.

In the video, I made 2 passes.

1. a small first pass to ensure penetration to the root of the joint

2. a second pass to achieve the fillet weld size.

Typically a 5f tig fillet weld test would first be visually inspected,

Then a cut is made in a specified area ( somewhere between 6 and 9 o clock area)  for a macro etch test, and finally a small section would be tested by a break test.

Cross sections from the cut are polished and then chemical etchants are used to reveal the difference between the weld nugget and base metal.

When metal is polished, it can smear over small defects so the etching process reveals the true weld nugget.

Different chemicals are used for different metals.

For example, for carbon steels, a 5% nitric acid solution is often used.

But for aluminum, a caustic solution like sodium hydroxide is often an effective etchant to show a weld nugget on an aluminum fillet weld.