Final answer:
To reduce stress in a weld, use a special type of hammer for cooling the joint as it cools.
Step-by-step explanation:
To reduce stress in a weld, a special type of hammer can be used for cooling the joint as it cools. One method to reduce stress in a weld is by cooling it at a controlled rate, which can be achieved by submerging the joint in water. This helps to prevent the formation of cracks or distortion that may occur due to rapid cooling. Another method is by rubbing the joint with a cloth, as it can help in reducing the stress by relieving any residual strain in the material.