1The EverydayPocket Handbookfor Gas Metal ArcWelding (GMAW)of Aluminum

Compiled as a useful tool foron-the-job welding personnel by theAWS Product Development Committee

Number 8 in a series

2NOTE: Although care was taken in choosing and presenting the data in this guide, AWS cannot guarantee that it iserror free. Further, this guide is not intended to be an exhaustive treatment of the topic and therefore may not include all

available information, including with respect to safety and health issues. By publishing this guide, AWS does not insure

anyone using the information it contains against any liability or injury to property or persons arising from that use.

Edited byLee G. Kvidahl

Ingalls Shipbuilding

1998 by American Welding Society. All rights reservedPrinted in the United States of America

3Basic Safety Precautions ...........................................4Typical Joint Geometries for Arc Welding

of Aluminum.........................................................6Designations for Wrought Alloy Groups ..................9Chemical Composition of Wrought Aluminum

Filler Metals........................................................10Typical Aluminum Filler Metal Properties

(As-Welded Condition).......................................11Guide to the Selection of Filler Metal for General

Purpose Welding .................................................12Influence of Shielding Gas on Weld Profile............15Typical Procedures for Gas Metal Arc Welding

of Groove Welds in Aluminum Alloys withArgon Shielding..................................................16

Typical Procedures for Gas Metal Arc Weldingof Fillet Welds in Aluminum Alloys withArgon Shielding..................................................18

Typical Procedures for Flat Position Gas MetalArc Welding Groove Welds in AluminumAlloys with Large Diameter Electrodes..............19

Joint Geometry Types ............................................. 21Typical Procedures for Gas Metal Arc Welding

of Fillet Welds in Aluminum Alloys withLarge Diameter Electrodes and ArgonShielding............................................................. 22

Aluminum Welding Wire........................................ 23Preparation of Aluminum for Welding ................... 24

Storage of Base Metal......................................... 24Storage of Consumables ..................................... 24Plate Edge Preparation........................................ 24Cleaning Prior to Welding .................................. 24Oxide Removal with Wire Brushing................... 25Shielding Gas Purity ........................................... 25

Tips to Make the Aluminum Welding JobEasier .................................................................. 26

Troubleshooting ...................................................... 27Basic Welding Symbols and Their Location

Significance........................................................ 28Location of Elements of a Welding Symbol ........... 30

Table of Contents

4Burn Protection. Molten metal, sparks, slag,and hot work surfaces are produced by welding,cutting, and allied processes. These can causeburns if precautionary measures are not used.Workers should wear protective clothing madeof fire-resistant material. Pant cuffs, open pock-ets, or other places on clothing that can catchand retain molten metal or sparks should not beworn. High-top shoes or leather leggings andfire-resistant gloves should be worn. Pant legsshould be worn over the outside of high-topshoes. Helmets or hand shields that provide pro-tection for the face, neck, and ears, and a headcovering to protect the head should be used. Inaddition, appropriate eye protection should beused.

Electrical Hazards. Electric shock can kill.However, it can be avoided. Live electrical partsshould not be touched. The manufacturersinstructions and recommended safe practicesshould be read and understood. Faulty installa-tion, improper grounding, and incorrect opera-tion and maintenance of electrical equipmentare all sources of danger.

All electrical equipment and the workpieceshould be grounded. The workpiece lead isnot a ground lead. It is used only to completethe welding circuit. A separate connection isrequired to ground the workpiece. The work-piece should not be mistaken for a groundconnection.

Basic Safety Precautions

5Fumes and Gases. Many welding, cutting,and allied processes produce fumes and gaseswhich may be harmful to health. Avoid breath-ing the air in the fume plume directly above thearc. Do not weld in a confined area without aventilation system. Use point-of-welding fumeremoval when welding galvanized steel, zinc,lead, cadmium, chromium, manganese, brass, orbronze. Do not weld on piping or containersthat have held hazardous materials unless thecontainers have been inerted properly.

Compressed Gas Cylinders. Keep caps oncylinders when not in use. Make sure that gas

cylinders are chained to a wall or other struc-tural support.

Radiation. Arc welding may produce ultra-violet, infrared, or light radiation. Always wearprotective clothing and eye protection to pro-tect the skin and eyes from radiation. Shieldothers from light radiation from your weldingoperation.

Refer to AWS/ANSI Z49.1, Safety in Welding,Cutting, and Allied Processes, for additionalinformation.

6Typical Joint Geometries for Arc Welding of Aluminum (Not to Scale)

7Typical Joint Geometries for Arc Welding of Aluminum (Continued) (Not to Scale)

8Typical Joint Geometries for Arc Welding of Aluminum (Continued)

9Designations for Wrought Alloy GroupsA system of four-digit numerical designations is used to identify wrought aluminum alloys. The first digit indicates the alloy group as follows:

Aluminum, 99.0% and greater 1XXX*

Major Alloying Element:

Copper 2XXX

Manganese 3XXX

Silicon 4XXX

Magnesium 5XXX

Magnesium and Silicon 6XXX

Zinc 7XXX

Other elements 8XXX

Unused series 9XXX

*For 1XXX series, the last two digits indicate the minimum aluminum purity (e.g., 1060 is 99.60% Al minimum). The second digit in all groups

indicates consecutive modifications of an original alloy, such as 5154, 5254, 5454, and 5654 alloys.

10

Chemical Composition of Wrought Aluminum Filler Metals

Filler Alloy

Elements, wt. %aOther

ElementsAlSi Fe Cu Mn Mg Cr Zn Ti Each Total

1100 Note b Note b 0.050.20 0.05 0.10 0.05c 0.15 99.0 min.01188 0.06 0.06 0.005 0.01 0.01 0.03 0.01 0.01c 99.88 min.2319 0.20 0.03 5.86.8 0.200.40 0.02 0.10 0.100.20 0.05c 0.15 Remainder4009d 4.55.5 0.20 1.01.5 0.10 0.450.60 0.10 0.100.20 0.05c 0.15 Remainder4010e 6.57.5 0.20 0.20 0.10 0.300.45 0.10 0.20 0.05c 0.15 Remainder4011f 6.57.5 0.20 0.20 0.10 0.450.70 0.10 0.040.20 0.05f 0.15 Remainder4043 4.56.0 0.80 0.30 0.05 0.05 0.10 0.20 0.05c 0.15 Remainder4047 11.013.0 0.80 0.30 0.15 0.10 0.20 0.05c 0.15 Remainder4145 9.310.7 0.80 3.34.7 0.15 0.15 0.15 0.20 0.05c 0.15 Remainder4643 3.64.6 0.80 0.10 0.05 0.100.30 0.10 0.15 0.05c 0.15 Remainder5183 0.40 0.40 0.10 0.501.00 4.35.2 0.050.25 0.25 0.15 0.05c 0.15 Remainder5356 0.25 0.40 0.10 0.050.20 4.55.5 0.050.20 0.10 0.060.20 0.05c 0.15 Remainder5554 0.25 0.40 0.10 0.501.00 2.43.0 0.050.20 0.25 0.050.20 0.05c 0.15 Remainder5556 0.25 0.40 0.10 0.501.00 4.75.5 0.050.20 0.25 0.050.20 0.05c 0.15 Remainder5654 Note g Note g 0.05 0.01 3.13.9 0.150.35 0.20 0.050.15 0.05c 0.15 Remainder

a. Single values are maximum, except where otherwise specified. e. Same composition as A356.0 cast alloy.

b. Silicon plus iron shall not exceed 0.95 percent. f. Beryllium content is 0.04 to 0.07 percent. Same composition

c. Beryllium shall not exceed 0.0008 percent. as A357.0 cast alloy. Used for GTAW rod only.

d. Same composition as C355.0 cast alloy. g. Silicon plus iron shall not exceed 0.45 percent.

11

Typical Aluminum Filler Metal Properties (As-Welded Condition)

Filler Alloy

Minimum Shear StrengthAll-Weld-Metal

Ultimate Tensile Strength

ksi MPa ksi MPa

1100 7.5 52 13.5 93

2319 16.0 110 37.5 258

4043 11.5 79 29.0 200

5183 18.5 128 41.0 283

5356 17.0 117 38.0 262

5554 17.0 117 33.0 230

5556 20.0 138 42.0 290

5654 12.0 83 32.0 221

12

Guide to the Selection of Filler Metal for General Purpose Weldinga,b,c

Base Metal

201.0, 206.0, 224.6.

319.0, 333.0, 354.0, 355.0,

C355.0.

356.0, A356.0, 357.0, A357.0, 413.0, 443.0,

A444.0.

511.0, 512.0, 513.0, 514.0,

535.0.

7004, 7005, 7039, 701.0,

712.0.6009, 6010,

6070.

6005, 6061, 6063, 6101, 6151, 6201, 6351, 6951. 5456 5454

1060, 1070,

1080, 1350

ER4145 ER4145 ER4043d,e ER5356e,f,g ER5356e,f,g ER4045d,e ER4043e ER5356g ER4043e,g

1100, 3003,

Alc. 3003

ER4145 ER4145 ER4043d,e ER5356e,f,g ER5356e,f,g ER4043d,e ER4043e ER5356g ER4043e,g

2014, 2036 ER4145h ER4145h ER4145 ER4145 ER4145

2219 ER2319d ER4145h ER4145e,f ER4043e ER4043e ER4043d,e ER4043d,e ER4043e

3004, Alc. 3004 ER4043e ER4043e ER5356i ER5356i ER4043e ER4043e,i ER5356g ER5356i

5005, 5050 ER4043e ER4043e ER5356i ER5356i ER4043e ER4043e,i ER5356g ER5356i

5052, 5652l ER4043e ER4043e,i ER5356i ER5356i ER4043e ER5356f,i ER5356i ER5356i

5083 ER5356e,f,g ER5356g ER5183g ER5356g ER5183g ER5356g

5086 ER5356e,f,g ER5356g ER5356g ER5356g ER5356g ER5356g

5154, 5254l ER4043e,i ER5356i ER5356i ER5356i ER5356i ER5356i

a. Service conditions such as immersion in fresh or salt water, exposure to specific chemicals, or a sustained high temperature [over 150F (66C)] maylimit the choice of filler metals. Filler metals ER5183, ER5356, ER5556, and ER5654 are not recommended for sustained elevated-temperature service.

b. Recommendations in this table apply to gas shielded arc welding processes. For oxyfuel gas welding, only ER1188, ER1100, ER4043, ER4047, andER4145 filler metals are ordinarily used.

c. Where no filler metal is listed, the base metal combination is not recommended for welding.d. ER4145 may be used for some applications.e. ER4047 may be used for some applications.f. ER4043 may be used for some applications.g. ER5183, ER5356, or ER5556 may be used.h.m. See table footnotes on next page.

13

Guide to the Selection of Filler Metal for General Purpose Weldinga,b,c (Continued)

Base Metal,5154,l5254l 5086 5083

,5052, l5652l

5005,5050,

3004, Alc. 3004 2219

2014, 2036,

1100, 3003,

Alc. 30031060, 1070, 1080, 1350.

1060, 1070,

1080, 1350

ER5356e,f,g ER5356g ER5356g ER4043e,g ER1100e,f ER4043e,g ER4145e,f ER4145 ER1100e,f ER1188e,f,k,m

1100, 3003,

Alc. 3003

ER5356e,f,g ER5356g ER5356g ER4043e,g ER1100e,f ER4043e,g ER4145e,f ER4145 ER1100e,f

2014, 2036 ER4145 ER4145 ER4145h ER4145h

2219 ER4043e ER4043e,g ER4043d,e ER4043d,e ER2319d

3004, Alc. 3004 ER5356i ER5356g ER5356g ER5356e,f,i ER5356f,i ER5356f,i

5005, 5050 ER5356i ER5356g ER5356g ER5356e,f,g ER5356f,i

5052, 5652l ER5356i ER5356g ER5356g ER5654f,i,l

5083 ER5356g ER5356g ER5183g

5086 ER5356g ER5356g

5154, 5254l ER5654i,l

a.g. See table footnotes on preceding page.h. ER2319 may be used for some applications. It can supply high strength when the weldment is postweld solution heat-treated and aged.i. ER5183, ER5356, ER5554, ER5556, and ER5654 may be used. In some cases, they provide: (1) improved color match after anodizing treatment,

(2) highest weld ductility, and (3) higher weld strength. ER5554 is suitable for sustained elevated-temperature service.j. ER4643 will provide high strength in 1/2 in. (12.7 mm) and thicker groove welds in 6XXX alloys when postweld solution heat-treated and aged.k. Filler metal with the same analysis as the base metal is sometimes used. Filler alloys ER4009 or R4009, ER4010 or R4010, and R4011 meet the

chemical composition limits of R-C355.0, R-A356.0, and R-A357.0 alloys, respectively.l. Base metal alloys 5254 and 5652 are useful for hydrogen peroxide service. ER5654 filler metal is used for welding both alloys for low-temperature

service [150F (66C) and below].m. ER1100 may be used for some applications.

14

Guide to the Selection of Filler Metal for General Purpose Weldinga,b,c (Continued)

Base Metal

201.0, 206.0, 224.6.

319.0, 333.0, 354.0, 355.0,

C355.0

356.0, A356.0, 357.0, A357.0, 413.0, 443.0,

A444.0

511.0, 512.0, 513.0, 514.0,

535.0

7004, 7005, 7039, 701.0,

712.0

6009, 6010,6070.

6005, 6061, 6063, 6101, 6151, 6201, 6351, 6951. 5456 5454

5454 ER4043e ER4043e,i ER5356i ER5356i ER4043e ER5356f,i ER5356i ER5554h,i

5456 ER5356e,f,g ER5356g ER5556g ER5356g ER5556g

6005, 6061, 6063,

6101, 6151, 6201,

6351, 6951

ER4145 ER4145e,f ER4043e,i,j ER5356i ER5356e,f,i ER4043d,e,j ER4043e,i,j

6009, 6010, 6070 ER4145 ER4145e,f ER4043d,e,j ER4043e ER4043e ER4043e,i,j

7004, 7005, 7039,

710.0, 712.0

ER4043e ER4043e,i ER5356i ER5356g

511.0, 512.0,

513.0, 514.0, 535.0

ER4043e,i ER5356i

356.0, A356.0,

357.0, A357.0,

413.0, 443.0,

A444.0

ER4145 ER4145e,f ER4043e,k

319.0, 333.0,

354.0, 355.0,

C355.0

ER4145h ER4145e,f,k

201.0, 206.0, 224.0 ER2319d,k

a.m. See table footnotes on previous page.

15

DIRECT CURRENT ELECTRODE POSITIVE (DCEP)

Influence of Shielding Gas on Weld Profile

16

Typical Procedures for Gas Metal Arc Welding ofGroove Welds in Aluminum Alloys with Argon Shielding

Section Thickness

Welding Positiona

Joint Geom-etryb

Root Opening No. of Weld

Passes

Electrode Diameter

Welding Current (DCEP),

A

ArcVolt-age,

V

Shielding Gas Flow Ratec Travel Speed

in. mm in. mm in. mm ft3/h L/min in./min mm/s0.06 1.6 F

F

A

G

0

0.09

0

2.4

1 .030 0.8 70110 1520 25 12 2545 10.519.0

0.09 2.4 F

F,V,H,O

A

G

0

0.12

0

3.2

1

1

.030.047

.030

0.81.2

0.8

90150

110130

1822

1823

30

30

14

14

2545

2330

10.519.0

9.712.7

0.12 3.2 F,V,H

F,V,H,O

A

G

0.09

0.19

2.4

4.6

1

1

.030.047

.030.047

0.81.2

0.81.2

120150

110135

2024

1923

30

30

14

14

2430

1828

10.212.7

7.611.8

0.19 4.8 F,V,H

F,V,H

O

F,V

H,O

B

F

F

H

H

0.06

0.06

0.06

0.090.19

0.19

1.6

1.6

1.6

2.44.8

4.8

2

1

2

2

3

.030.047

.047

.047

.047.062

.047

0.81.2

1.2

1.2

1.21.6

1.2

130175

140180

140175

140185

130175

2226

2327

2327

2327

2327

35

35

60

35

60

16

16

28

16

28

2430

2430

2430

2430

2535

10.312.7

10.312.7

10.312.7

10.312.7

10.514.8

0.25 6.4 F

F

V,H

O

F,V

O,H

B

F

F

F

H

H

0.09

0.09

0.09

0.09

0.120.25

0.25

2.4

2.4

2.4

2.4

3.36.4

6.4

2

2

3F,1R

3F,1R

23

46

.047.062

.047.062

.047

.047.062

.047.062

.047.062

1.21.6

1.21.6

1.2

1.21.6

1.21.6

1.21.6

175200

185225

165190

180200

175225

170200

2428

2429

2529

2529

2529

2529

40

40

45

60

40

60

19

19

21

28

19

28

2430

2430

2535

2535

2430

2540

10.312.7

10.312.7

10.514.8

10.514.8

10.312.7

10.516.9

a. F = flat; V = vertical; H = horizontal; O = overhead.

b. Refer to pages 68.

c. Nozzle ID = 5/8 to 3/4 in. (15.9 to 19 mm).

17

Typical Procedures for Gas Metal Arc Welding ofGroove Welds in Aluminum Alloys with Argon Shielding (Continued)

Section Thickness

Welding Positiona

Joint Geom-etryb

Root Opening No. of Weld

Passes

Electrode Diameter

Welding Current (DCEP),

A

ArcVolt-age,

V

Shielding Gas Flow Ratec Travel Speed

in. mm in. mm in. mm ft3/h L/min in./min mm/s0.38 9.6 F

F

V,H

O

F,V

O,H

C-90

F

F

F

H

H

0.09

0.09

0.09

0.09

0.250.38

0.38

2.4

2.4

2.4

2.4

6.49.6

9.6

1F,1R

2F,1R

3F,1R

5F,1R

4

810

.062

.062

.062

.062

.062

.062

1.6

1.6

1.6

1.6

1.6

1.6

225290

210275

190220

200250

210290

190260

2629

2629

2629

2629

2629

2629

50

50

55

80

50

80

24

24

26

38

24

38

2030

2435

2430

2540

2430

2540

8.512.7

10.314.8

10.312.7

10.516.9

10.312.7

10.516.9

0.75 19.0 F

F

V,H,O

F

V,H,O

C-60

F

F

E

E

0.09

0.12

0.06

0.06

0.06

2.3

3.2

1.6

1.6

1.6

3F,1R

4F,1R

8F,1R

3F,3R

6F,6R

.062.094

.094

.062

.062

.062

1.62.4

2.4

1.6

1.6

1.6

340400

325375

240300

270330

230280

2631

2631

2631

2631

2631

60

60

80

60

80

28

28

38

28

38

1420

1620

2430

1624

1624

5.98.5

6.88.5

10.312.7

6.810.3

6.810.3

a. F = flat; V = vertical; H = horizontal; O = overhead.

b. Refer to pages 68.

c. Nozzle ID = 5/8 to 3/4 in. (15.9 to 19 mm).

18

Typical Procedures for Gas Metal Arc Welding ofFillet Welds in Aluminum Alloys with Argon Shielding

Section Thickness

Welding aPositiona

No. of Weld

Passes

Electrode DiameterWelding Current (DCEP),

A

ArcVoltage,

V

Shielding Gas Flow Rateb Travel Speed

in. mm in. mm ft3/h L/min in./min mm/s0.094 2.4 F,V,H,O 1 0.030 0.8 100130 1822 30 14 2430 1013

0.125 3.2 F

V,H

O

1

1

1

0.0300.047

0.030

0.0300.047

0.81.2

0.8

0.81.2

125150

110130

115140

2024

1923

2024

30

30

40

14

14

19

2430

2430

2430

1013

1013

1013

0.19 4.8 F

V,H

O

1

1

1

0.047

0.0300.047

0.0300.047

1.2

0.81.2

0.81.2

180210

130175

130190

2226

2125

2226

30

35

45

14

16

21

2430

2430

2430

1013

1013

1013

0.25 6.4 F

V,H

O

1

1

1

0.0470.062

0.047

0.0470.062

1.21.6

1.2

1.21.6

170240

170210

190220

2428

2327

2428

40

45

60

19

21

28

2430

2430

2430

1013

1013

1013

0.38 9.6 F

H,V

O

1

3

3

0.062

0.062

0.062

1.6

1.6

1.6

240300

190240

200240

2629

2427

2528

50

60

65

24

28

31

1825

2430

2430

811

1013

1013

c0.75c 19.0 F

H,V

O

4

46

10

0.094

0.062

0.062

2.4

1.6

1.6

360380

260310

275310

2630

2529

2529

60

70

85

28

33

40

1825

2430

2430

811

1013

1013

a. F = flat; V = vertical; H = horizontal; O = overhead.b. Nozzle ID = 5/8 to 3/4 in. (15.9 to 19 mm),c. For thickness of 0.75 in. (19 mm) and larger, double-bevel joint with a 50 degree minimum groove angle and 0.09 to 0.13 in. (2.3 to 3.3 mm) root face

is sometimes used.

19

Typical Procedures for Flat Position Gas Metal Arc Welding Groove Weldsin Aluminum Alloys with Large Diameter Electrodes

Section Thickness,

T

Joint GeometryElectrode Diameter Shielding

GasWeld Passb

Arc Voltage,

V

Welding Current, (DCEP),

AcTravel Speed

Typea F

in. mm Degrees in. mm in. mm in./min mm/s0.75 19.0 A 90 0.25 6.3 0.156 4.0 Ar 1

228 450

50016 6.8

1.00 25.4 A 90 0.13 3.3 0.188 4.8 Ar 1,2 26.5 500 12 5.1

1.25 31.8 A 70 0.18 4.6 0.188 4.8 Ar 1,2 26.5 550 10 4.2

1.25 31.8 B 45 0.25 6.3 0.156 4.0 Ar 12

Back

252726

500 101012

4.24.25.1

1.50 38.1 A 70 0.18 4.6 0.188 4.8 Ar 12

3,4

262729

550575600

10 4.2

1.50 38.1 A 70 0.18 4.6 0.219 5.56 Ar 12

2727.5

650675

8 3.4

1.75 44.5 A 70 0.13 3.3 0.219 5.56 Ar 1,23,4

2627

650600

10 4.2

1.75 44.5 B 45 0.25 6.3 0.188 4.8 Ar 1,23,4

Back

283030

600550550

101410

4.25.94.2

a. The joint types shown on page 21 are referred to by letter in the indicated column under joint geometry.b. All passes are welded in the flat position, odd numbers from one side and even numbers from the other side with joint designs (A) and (C). Joint is

backgouged prior to depositing the back weld.c. Constant current dc power source and constant-speed electrode drive unit.

20

Typical Procedures for Flat Position Gas Metal Arc Welding Groove Weldsin Aluminum Alloys with Large Diameter Electrodes (Continued)

Section Thickness,

T

Joint GeometryElectrode Diameter

Shielding Gas

Weld Passb

Arc Voltage,

V

Welding Current, (DCEP),

AcTravel Speed

Typea F

in. mm Degrees in. mm in. mm in./min mm/s2.00 50.8 A 70 0.2 4.6 0.188 4.8 He 1,2,3,4 32 550 10 4.2

2.00 50.8 B 45 0.3 6.3 0.188 4.8 Ar 1.237

Back

282628

600500550

101410

4.25.94.2

3.00 76.2 A 70 0.18 4.6 0.219 5.56 Ar-25%He 1,23,45,6

710

25232627

650500650625

910

99

3.84.23.83.8

3.00 76.2 C 30 0.50 12.7 0.219 5.56 He 1,236

2931

650 10 4.2

a. The joint types shown on page 21 are referred to by letter in the indicated column under joint geometry.b. All passes are welded in the flat position, odd numbers from one side and even numbers from the other side with joint designs (A) and (C). Joint is

backgouged prior to depositing the back weld.c. Constant current dc power source and constant-speed electrode drive unit.

21

Joint Geometry Types

22

Typical Procedures for Gas Metal Arc Welding of Fillet Welds inAluminum Alloys with Large Diameter Electrodes and Argon Shielding

Fillet SizeElectrode Diameter

Weld Passa

Welding Current,

AbArc Voltage,

VTravel Speed

in. mm in. mm in./min mm/s0.50 12.7 0.156 4.0 1 525 22 12 5.10.50 12.7 0.188 4.8 1 550 25 12 5.1

0.63 16.0 0.156 4.0 1 525 22 10 4.2

0.75 19.0 0.156 4.0 1 600 25 10 4.2

0.75 19.0 0.188 4.8 1 625 27 8 3.4

1 25.4 0.156 4.0 12,3

600555

2524

1210

5.14.2

1 25.4 0.188 4.8 12,3

625550

2728

812

3.45.1

1.25 31.8 0.156 4.0 1,2,3 600 25 10 4.2

1.25 31.8 0.188 4.8 12,3

625600

2728

810

3.44.2

a. Welded in the flat position with one or three passes, using stringer beads.

b. Constant-current power source and constant-speed electrode wire drive unit.

23

Aluminum Welding Wire

Fraction Decimal Millimeters

FeetApproximate Wire Gaugeper lb. per kg

0.23 0.6 2083 4592 23

.030 0.8 1215 2678 20-1/2

.035 0.9 900 1984 19

.040 1.0 704 1552 18

3/64 .047 1.2 520 1146 17

.059 1.5 308 679 15

1/16 .062 1.6 290 639 14

.079 2.0 172 379 12

3/32 .093 2.4 130 287 11

1/8 .125 3.2 70 154 8

5/32 .156 4.0 45 99 6-1/2

3/16 .187 4.7 31 68 4-1/2

1/4 .250 6.3 20 44 2

24

Storage of Base Metal. Base metal shouldbe stored inside in a dry room, and covered toprevent a buildup of shop dust.

Storage of Consumables. Aluminum rodsand coils of filler metal should be stored indoorsin a dry room, and ideally should be kept warm.Once the package is opened, the filler metalshould be stored in an oven to avoid moisturebuildup on the metal surface. A storage tem-perature of 100F (40C) is adequate, but themanufacturers recommendation should beconsulted.

Plate Edge Preparation. Aluminum plateedges can be prepared by any of the conven-tional mechanical machining processes.

The plasma arc cutting process can be usedto make square edge or bevel cuts in aluminum.

When plasma cutting the 2XXX, 6XXX, or7XXX series alloys, it may be necessary tomechanically remove as much as 1/8 in.(3.2 mm) from the plasma cut edge to eliminatethe crack-prone heat-affected zone. The series1XXX, 3XXX, and 5XXX aluminum alloys arenot as crack sensitive and can usually be weldedas-cut.

Cleaning Prior to Welding. Several excel-lent metal cleaners are available on the market,and the metal fabricator should study the fea-tures of each. After the cleaners have done theirjob, the surfaces to be welded should be given afinal wipe with a clean cloth soaked in acetone.Since acetone and similar cleaning agents arehighly flammable, care must be taken to avoidexposing the fumes or open containers to asource of ignition.

Preparation of Aluminum for Welding

25

Compressed air, which may contain moisture oroil from the compressor, should not be used toblow off areas cleaned by solvents.

Oxide Removal with Wire Brushing.Some fabricators have found it helpful to wirebrush the area to be welded after chemical clean-ing and before the final wipe with acetone. Thisshould be done with a stainless steel wire brushused only for brushing aluminum. The wirebrush is dedicated to brushing aluminum toavoid bringing in impurities from other workpieces. While brushing, the operator should becareful to avoid smearing the surface of the alu-minum and trapping impurities under the smears.

Shielding Gas Purity. Argon, helium, ormixtures of the two can be used for gas metal

arc welding of aluminum. Shielding gas usedfor welding aluminum should have a dew pointno higher than 70F (57C). Using shieldinggas with a higher dew point may result in poros-ity in the weld.

For an expanded discussion of the shieldinggases to be used when arc welding aluminum, seethe AWS Handbook, Eighth edition, Volume 3.

A simple way to check for argon purity is tostrike a gas tungsten arc on a clean piece of6061 aluminum. Holding the torch stationary,form a puddle. If the puddle has a bright, silveryappearance, the gas is pure enough for welding.If a brown spot appears to be floating on thepuddle, there is a problem with gas purity. Notethat the argon may be of adequate purity, but theshielding gas may pick up impurities because ofholes in the gas hose.

26

Use the proper welding power source. Aconstant current unit is best for welding alu-minum because it does not permit the highcurrent surges produced by constant voltagemachines. These surges cause arcing insidethe guide tube which results in deposits thatimpede wire feed.

If the torch cables are more than 12 ft(3.6 m) long, a push-pull wire feed systemshould be considered.

Feed rolls with a U-groove rather than aV-groove or knurled surface should be used.Make sure that drive roll pressure isnt exces-sive, because that will tend to distort the wire.

A straight barrel torch should be used ratherthan a goose-neck torch to minimize frictionin the wire feed system.

Teflon or nylon wire feed conduits should beused to reduce friction in the wire feed sys-tem. When aluminum particles from the wirefeed rolls accumulate in the conduits, theconduits should be replaced. Some usersreport improved operation by blowing theparticles out using argon, but usually it isbest to replace the worn parts.

After a burnback, it is best to replace thewhole length of electrode in the conduit.Otherwise, the slightest kink in the wire leftin the conduit may cause another jam.

Tips to Make the Aluminum Welding Job Easier

27

Problem Possible Cause Remedy

Porosity Contamination from dirt on plate or wire Clean base metalKeep filler metal clean and dry

Contaminated shielding gas Shield weld area from draftsCheck hoses for leaks

Poor arc starting Bad workpiece connection Reconnect workpiece cable

Weld cracking Wrong filler metal See filler metal selection guide

Electrode burnback Insufficient wire feed Increase wire feed speed

Worn or dirty conduit liner Replace liner

Color mismatch after anodizing Use of 4XXX filler metal See filler metal selection guide

Troubleshooting

28

Basic Welding Symbols and Their Location SignificanceRefer to AWS A2.4, Standard Symbols for Welding, Brazing, and Nondestructive Examination, for more information.

29

Basic Welding Symbols and Their Location Significance (Continued)

30

Location of Elements of a Welding Symbol

{?IR?xh