Where should you start applying the solder metal for joints in the horizontal position?

When soldering joints in a horizontal position, it is optimal to start applying the solder metal off center at the bottom of the joint. This technique ensures that the heat rises and helps the solder to flow upwards through the joint, creating a strong and effective bond.

By commencing at the bottom, the heat allows the solder to be drawn into the joint as it melts, which promotes even distribution throughout the joint. This method prevents overheating at the top of the joint and avoids issues that can arise if the solder were to drip down or not fill the joint properly. Overall, initiating the application of solder from the bottom helps create a cohesive connection that enhances the overall strength and reliability of the joint.