Get started to mig welding (Part 3)

Get started to mig welding (Part 3)

Date 06/05/2019

1.DC Electrode Positive

Set the mig welding machine polarity to DC Electrode Positive (DCEP ) This is reverse polarity 

mig welding machine

2.Keep a consistent electrode length

As you are welding in mig welding machine, keep your electrode extended between 1/4" and 3/8" from the contact tube. This will help make for a clean, regular weld

3.Use the proper shielding gas

Use carbon dioxide as an economical choice to provide deeper penetration on steel. This will be too hot for hin metal though. Use argon for aluminum welding, and a mix of argon 75%) and carbon dioxide (25%) for thinner steel

4. Weld a joint using a drag or push welding technique

The angle should not exceed 10 degrees in either technique. Keep the wire at the front edge of your weld pool. This will give you greater control over your weld 

Drag welding pulls the bead along with the tip. This will give you a deeper penetration and a narrower bead

Push welding pushes the bead with the tip. This will give you a wider bead

push welding technique

5. Make a flat weld

Use the welder to place material directly into the joint. You can use a back and forth method to fill large gaps. For flat joints, hold the gun at a 90 degree angle

6. Make a horizontal weld 

You must lower the gun angle slightly to keep the filler from sagging. Keep the same push or pull angle as normal . Use a back and forth weave motion to fill large gaps

Keep the amperage the same as a flat weld. You may need to use a slightly smaller diameter wire to keep the weld pool from getting too big 

7. Make the vertical weld to mig welding machine. 

For thin materials, start at the top and move the pool down with gravity . This keeps the arc from penetrating the material. For thicker metals, start at the base and work up. This will help increase penetration

You may want to lower the amperage by around 10-15% to help fight gravity

8.Make an overhead weld to mig welding

Use standard welding techniques, but increase you travel speed. This will help prevent filler from falling out of the joint. You may need to increase your gas flow rate

Keep your nozzle clean, as spatter will build up faster when welding overhead

9. Finish the weld

Once you are done with the weld process, grind off any excess filler. If the weld is defective, grind it down and re-weld the joint