Weld Aluminum

Welding is the process of joining 2 metal components by melting them together. Welding any material is a challenging process requiring experience; welding lightweight metals like aluminum requires the utmost precision to ensure a strong bond. Knowing how to weld aluminum is a matter of assembling the right tools, exercising caution and patience, and gaining experience. Follow this guide to weld aluminum with a TIG welder.

Steps

Preparing to Weld

  1. Assemble the tools you'll need. To weld aluminum, you will need several tools.
    • TIG (tungsten inert gas) welder. This type of welder uses a tungsten electrode and an inert gas to shield the welding area. The precision achieved with this type of welder is crucial when working with aluminum, especially thin pieces.
      • TIG welders are expensive, so look into rental possibilities. Contact a local welding supply store or home hardware outlet and inquire about rental possibilities.
      • It is possible to weld aluminum with other welding processes, such as MIG welding, but TIG welding is the most painless method and is well-suited for beginners.
    • Aluminum filler rod. This is the material that will bond the two pieces. Try to avoid using rusty or dirty filler rods, as these will lead to weaker welds.
    • A canister of argon gas for use as shielding. Pure argon is a cost effective gas solution. 3% helium can be added to increase arc stability.
      • Gas needs to be acquired from authorized gas dealers. Most welding supply stores will be able to provide gas or refer you to an outlet that can.
  2. Make sure to use all of the proper safety equipment. Welding requires a bevy of personal protective equipment. Make sure to wear a heavy welding helmet and a pair of thick gloves (the thicker the better). You will need to wear a shirt with long sleeves made from a thick fabric; TIG welding produces a large amount of ultraviolet radiation, and if you weld in short sleeves you will get burns along your arms.
    • Try to find a shirt that is thick, 100% cotton.
    • Your welding gloves should be insulated and fire-resistant.
    • Try to use a helmet with a lens that automatically darkens during the welding process. The lens should be rated at 10-13 shade.
    • Make sure that your pants do not have cuffs that can catch flaming material.
    • Keep a fire extinguisher easily accessible in case of any stray sparks.
  3. Clean the aluminum. Over time, aluminum forms a thin coat of aluminum oxide on its exterior, which melts at a much higher temperature than aluminum. So, before welding any piece of aluminum (even a brand new piece), you have to clean away the aluminum oxide.
    • Spray the joints with acetone. Rinse the work piece in water, and then allow it to dry thoroughly. Scrub the aluminum with a stiff brush with stainless steel bristles to finish the cleaning process.
    • The welder itself will clean the metal as welds, but this is often not sufficient to remove all contaminants.
  4. Clean the filler rod. A dirty filler rod can contaminate the weld just as easily as a dirty work piece. Use an abrasive cleaning pad to ensure that the rod is contaminant free.

Practicing the Weld

  1. Brace the torch with your hand. For practice, keep the torch unlit to save metal. Using the base of your gloved hand on the table for support, hold the torch with a slight angle tilting back, about 10°. Hold the tip of the tungsten about 1/4" away from the aluminum.
    • If you pull the tip too far away, it will cause the arc to spread too much and the weld will become difficult to control.
  2. Move the torch. With the torch in proper position, practice moving your hand along the path that you will be welding. Make sure to practice with gloves on to simulate the amount of effort required. For small welds move your entire hand, instead of just the fingers.
  3. Hold the filler at the correct angle. You will lead the weld with the filler rod, which should be held at about a 90° angle to the torch tip. The torch should always be pushed and not dragged.
    • If the filler and the tip come into contact, your weld will be contaminated and lose structural integrity.

Welding the Metal

  1. Preheat the aluminum work piece. Aluminum is much easier to weld when the work is already much hotter than room temperature. When welding thick pieces of aluminum, welding without preheating can lead to a very weak, shallow bond.
    • You can heat the work piece by putting it directly in an oven, or you can use a gas torch to apply heat to the heat sink that the work is clamped to. This will distribute the heat throughout the work piece.
    • Aim for a temperature of about 350°F (176°C).
  2. Fit the work pieces together as tightly as possible. TIG welders will be unforgiving if the joint is not fitted very tightly; you will be left with gaps in the joint. Make the work pieces fit together as tightly as possible by filing them before clamping them together.
  3. Set the amperage of your welder. Aim to use about 1 amp per 0.001 inch (0.025 mm) of the work piece's thickness. It is a good idea to set the welder's amperage to higher than your expected need and then tone the current back with the foot pedal.
  4. Start the weld. Begin by extending the tungsten electrode no more than the diameter of the torch’s nozzle. For example, if you are using a 1/4" wide nozzle, your tungsten tip should extend no more than 1/4" from the nozzle. Tap the electrode tip against the work piece and then pull it away about 1/8 inch (3 mm). Use the foot pedal to create the electrical arc.
  5. Create the puddle. Melt the work piece until you have an adequately sized puddle. Add just enough of the filler rod to fill in the joint, and then move to the next portion of the weld. Continue until the entire joint is welded properly.
    • As you weld, heat will increase throughout the work piece. Use your foot pedal to lower the amperage as you go to maintain control of the puddle.
  6. Push the puddle. Slowly push the puddle that the torch creates down the joint, adding filler as you go. Move at an even pace to keep the puddle a consistent size.



Things You'll Need

  • TIG welder
  • Aluminum filler rod
  • Argon gas
  • Welding helmet
  • Thick gloves
  • Fire extinguisher
  • Long-sleeved shirt
  • Acetone
  • Water
  • Stainless steel brush
  • Gas torch
  • Heat sink
  • Clamps
  • File

Related Articles

Sources and Citations

You may like

Retrieved from "https://kipkis.com/index.php?title=Weld_Aluminum&oldid=364740"