How Do I Make The Perfect Weld? Or How Do I Prevent Porosity?

Q. How Do I Make The Perfect Weld? Or How Do I Prevent Porosity?

A. Regardless of the material to be welded, there are a few basic precautions which must be taken to avoid porosity in the weld and lack-of-fusion defects.

1. The material to be welded should be as clean as possible. All grease, oil, and other lubricants should be removed. For best quality welds, all scale, rust, and other oxide coverings should be either mechanically or chemically removed. This is of extreme importance when welding aluminum.

2. When welding carbon steel plate, use only the shielding gas-wire combination recommended for the specific variety of steel in use: killed, semi-killed, or rimmed.

For best quality welds, all scale, rust, and other oxide coverings should be either mechanically or chemically removed. This is of extreme importance when welding aluminum.

3. Generally avoid welding conditions which result in the weld bead solidifying very rapidly, such as very high travel speeds. Gas which would normally be evolved from the weld metal during cooling can be trapped, thereby causing porosity.

4. Maintain an adequate shielding gas flow and protect the welding area from wind and drafts.