What is frequently caused by improper heating of a joint or feeding of solder into the joint?

The phenomenon frequently caused by improper heating of a joint or incorrect feeding of solder into the joint is known as a void. A void occurs when there is a gap or empty space within the joint that should be filled with solder. This typically arises from inadequate heat causing solder to not flow properly into the joint or from solder being fed incorrectly, which can lead to a lack of adhesion and ultimately result in a weak or defective joint.

When soldering, it is critical to ensure uniform and adequate heating to allow the solder to properly fill the space between pipes, creating a reliable joint. If the joint itself doesn't reach the necessary temperature, the solder will not melt adequately or can solidify too quickly before filling all the necessary gaps. Consequently, the presence of voids can compromise the integrity of the joint and lead to leaks or failure under pressure.

In contrast, other terms such as bare spots, shiny areas, and burrs refer to different issues not directly resulting from the heating and feeding process during soldering.