GTAW on aluminum

Question 1

What is a stringer bead?

Answer 1

A stringer bead is a weld bead that is carried in the direction of travel with no side motion.

Question 2

How should you lay the stringer beads when surface welding for build-up work?
a) Space them so that they are 3.2 mm (1/8”) apart.
b) Blend them together so they form a solid layer of weld metal.
c) Space them so that they are 6 mm (1/4”) apart.
d) The toe of one bead should meet the toe of the next bead.

Answer 2

b) Blend them together so they form a solid layer of weld metal.

Question 3

In what positions can you do surface welding with GTAW on aluminum?
a) the flat position only
b) the flat and horizontal positions only
c) all positions except vertical
d) all positions

Answer 3

d) all positions

Question 4

Which type of power source is recommended for GTAW on aluminum?
a) AC constant current power source
b) DC constant potential power source
c) AC constant arc voltage power source
d) DC rising arc voltage power source

Answer 4

a) AC constant current power source

Question 5

Is it necessary to remove oxides and other foreign materials from the base metal prior to welding?
a) yes
b) no

Answer 5

a) yes

Question 6

Wire brushes should be made of_____________________ to prevent
contamination of aluminum prior to welding.
a) chromium-molybdenum steel
b) stainless steel
c) low carbon steel
d) non-ferrous metals

Answer 6

b) stainless steel

Question 7

Why should you weld the joint as soon as possible after cleaning?

Answer 7

because aluminum begins to oxidize immediately after cleaning.

Question 8

What may have to be done if the filler rods have been in storage for an extended period of time?

Answer 8

It may be necessary to remove the majority of the oxides from the filler rod with an abrasive material such as stainless steel wool. Otherwise you risk getting defects in the weld.

Question 9

How are wrought aluminum alloys visually identified?
a) by a pebbly appearance on the metal’s surface
b) by rolling marks and smooth finish
c) by casting mould marks
d) by smooth rounded corners and edges

Answer 9

b) by rolling marks and smooth finish

Question 10

The shielding gas most commonly used for GTAW on aluminum is:
a) carbon dioxide.
b) nitrogen.
c) helium.
d) argon.

Answer 10

d) argon.

Question 11

A larger nozzle size is generally required for GTAW of aluminum. This is because aluminum is:
a) a refractory metal.
b) a non-ferrous metal.
c) a reactive metal.
d) highly reflective.

Answer 11

c) a reactive metal

Question 12

GTAW using high-frequency current requires nozzles made of:
a) ceramic or quartz.
b) chrome-plated brass.
c) copper-plated stainless steel.
d) brass or low fuming bronze.

Answer 12

a) ceramic or quartz.

Question 13

Preheat applied to wrought aluminum components is:
a) accomplished using inductance heating methods only.
b) seldom required to exceed 149°C (300°F).
c) not applied unless the ambient temperature is below -18°C (0°F).
d) only done prior to solution heat treating.

Answer 13

b) seldom required to exceed 149°C (300°F).

Question 14

The recommended technique for GTAW on aluminum is:
a) low current settings with a long arc.
b) forehand inclination with continuous filler metal additions.
c) backhand inclination with continuous filler metal additions.
d) forehand inclination with dip technique filler metal additions.

Answer 14

d) forehand inclination with dip technique filler metal additions.

Question 15

The aluminum filler rod types recommended for the 1F, 2F and 3F projects are:
a) ER70S-2 and ER70S-6.
b) E4310 and E4918.
c) ER4043 and ER5356.
d) ER1100 and ER5556.

Answer 15

c) ER4043 and ER5356.

Question 16

Number and letter combinations such as 1F and 2F represent:
a) the type of filler metal and shielding gas to be used for the project.
b) the position and type of weld to be completed.
c) joint design and configuration.
d) the process and joint design to be used.

Answer 16

b) the position and type of weld to be completed.

Question 17

Identify three (3) methods that may be used for the preparation of aluminum.
a)
b)
c)

Answer 17

Any three (3) of the following are correct.
a) shearing
b) saw cutting
c) machining
d) plasma arc-cutting

Question 18

19. Why is it important to remove burrs from material edges before fitting up lap joints?

Answer 18

Burrs can cause artificial gaps.

Question 19

How is the work positioned for a 1F Tee joint?
a) 90° and 0° relative to the horizontal plane
b) 180° and 360° relative to the horizontal plane
c) 120° and 60° to the horizontal plane
d) each member at 45° to the horizontal plane

Answer 19

d) each member at 45° to the horizontal plane

Question 20

What is the purpose of tack welds?

Answer 20

Tack welds hold the parts in alignment until they can be welded.

Question 21

What is the normal electrode angle when doing single-pass fillet welds?
a) Electrode angle is completely dependent on the direction of travel.
b) Electrode angle is theoretically 1/2 the joint angle.
c) Electrode angle is dependent on the joint’s position.
d) Electrode angle is relative to the welder’s position.

Answer 21

b) Electrode angle is theoretically 1/2 the joint angle.

Question 22

Which of the following should you adjust to increase penetration on the root bead?
a) Increase voltage at the power source.
b) Decrease amperage by increasing arc length.
c) Increase arc length with an increase of amperage.
d) Incline the torch more perpendicular to the puddle.

Answer 22

d) Incline the torch more perpendicular to the puddle.

Question 23

Changing the inclination of the electrode holder in relation to the direction of travel:
a) changes the penetration of the arc.
b) has no effect on the weld.
c) causes the filler rod to freeze in the puddle.
d) causes the filler rod to feed unevenly.

Answer 23

a) changes the penetration of the arc.

Question 24

What action would you take to avoid a weld bead on a fillet weld from becoming too convex?
a) increase the amperage setting
b) add less filler metal and travel faster
c) travel slower to allow the puddle to become more fluid
d) angle the electrode to the top edge

Answer 24

c) travel slower to allow the puddle to become more fluid

Question 25

Do GTAW welds require post weld cleaning? Explain your answer.

Answer 25

GTAW leaves very little to clean after welding is completed. Many applications may be finished in the as-welded condition, but others require cleaning and finishing to meet appearance requirements.

Question 26

What is the recommended torch angle for a single pass 2F weld?
a) 90° to the vertical plane
b) 90° to the horizontal plane
c) 45° to the vertical and horizontal planes
d) 20° backhand to the direction of travel

Answer 26

c) 45° to the vertical and horizontal planes

Question 27

What may have to be done after tacking is completed?

Answer 27

Tack welds on aluminum can become oxidized. You may have to clean the joint again before starting to weld.

Question 28

What is a 3F position weld?

Answer 28

A 3F position weld is a weld in which the members being joined are in the vertical plane and the weld axis is vertical