What should be done to properly form soft aluminum over a mold?

To properly form soft aluminum over a mold, it is essential to fasten it tightly to the mold. This ensures that the aluminum maintains contact with the surface of the mold, which is crucial for achieving the desired shape and minimizing the risk of wrinkles or distortion during the forming process. By securing the aluminum, the material can be evenly manipulated and shaped, which leads to more precise and consistent results.

When aluminum is tightly fastened to the mold, it allows for better control over the forming process, as the material can conform closely without shifting or moving away from the mold shape. This technique is especially important in sheet metal work, where accuracy is vital for structural integrity and aesthetics.

The other methods, such as heating the aluminum before forming or using a thicker piece, might affect the forming process differently but are not the most straightforward or effective approach for ensuring a tight and accurate fit. Leaving the material loose may indeed make it easier to manipulate initially, but it would compromise the final shape and precision of the formed part, leading to defects or misalignments.