Aluminum is a non-ferrous silvery white metal with 1220°F melting point. Aluminum is a very popular metal because of its lightweight feature. From frames of bike to trailers of truck, aluminum is used everywhere.
Welding an aluminum plate is possible and you can do that with Tig, Mig or plasma welding. Tig welding with DC current flow is popular while it comes to welding thicker aluminum.
Today we will cover the machine settings for Tig welding 3/8″aluminum plate. Lets start-
Joints for 3/8 inch aluminum
We all know that there are multiple types of joint in welding. We will use discuss Butt, Lap, Corner & fillet joint in this case & also will find the machine settings.
Butt Joint 3/8″Aluminum
Butt joint is normal joint types where a piece of metal is welded to other placing them side by side.
| Features | Settings |
|---|---|
| Tungsten Electrode | You may use 3.32 mm diameter or 1/8 inch diameter tungsten electrode. Use 2% thoriated electrode for better penetration. |
| Torch Cup | You may use ceramic cup for less than 200amp but need to use water cooled torch for more than 250amps machine |
| Filler Metal | 4043 filler metal of 1/8″ (3.2mm) is ok for the project |
| Polarity | For thicker metal you should use DC polarity |
| Amperage | Ranging from 110 to 260amp. It depends on pass you are employing. For root pass you must use 3/32 filler @ 220-260amp and for cover pass 1/8 @ 110 to 130amp. |
| Gas | For thicker metal you may use Argon and for better result use argon & helium mix for deep penetration. Gas flow should be 29cft. |
Lap Joint 3/8″ Aluminum
Lap joint is another type of joint where two pieces of metal are welded overlapping each other.
| Feature | Settings |
|---|---|
| Machine | Use high amperage machine more than 125amps. |
| Tungsten Electrode | Use 1/8inch 2% ceriated tungsten |
| Torch Cup | Use 5/8″ water cooled torch cup |
| Amperage | Ranging from 230 to 250amp |
| Gas & Flow Rate | Use argon/helium mixture at 29cft for better weld |
Corner Joint
Corner joint is welding two pieces corner side by side as shown in the picture bellow
| Feature | Settings |
|---|---|
| Amperage | Ranging from 130 to 260 in 3 passes. 1st root pass @230-260amp, 2nd cover(1)@ 130-160amp and 3rd cover(2)@130-160amp. |
| Tungsten Electrode | Same as butt and lap joint requirements |
| Gas & flow rate | Same as lap joint requirement |
| Filler Diameter | Same as butt joint requirement |
| Polarity | DC |
Fillet Joint
Fillet joint is welding two pieces of metal one over another perpendicularly or in 90 degree angle.
| Feature | Settings |
|---|---|
| Amperage | Ranging from 240 to 270amp |
| Torch Cup | Same as butt and lap joint requirement |
| Tungsten Electrode | Same as but and lap joint |
| Gas & Flow Rate | Same as butt and lap joint |
Check Out Some 6061 Aluminum Plates For Projects
Important Notes
For Tig welding thicker aluminum you must pre-heat the aluminum and raise the temperature to at least 130°F. Doing so would make the aluminum ready for perfect welding and the penetration would be better.
Tig welding 3/8inch aluminum requires you to travel the torch slowly with steady hands. The benefit of tig welding 3/8inch aluminum is it produces less spatter and slags than other welding methods.
Lastly
It is not that difficult to weld thicker metal with tig welder if the correct settings are followed. Besides, if you have prior experience then it would be a piece of cake to tig weld aluminum. However, take necessary precautions before starting the welding and make sure you wear helmet and gloves.
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