What is a common disadvantage of using oxyacetylene torches?

The correct answer highlights a common disadvantage related to the operation of oxyacetylene torches. While oxyacetylene torches can indeed produce extremely high temperatures, which is often seen as an advantage for cutting and welding, this characteristic can also lead to difficulties when working with certain materials. Specifically, the intense heat can cause thin materials to warp or burn through, making it challenging to achieve clean and precise cuts or welds.

The disadvantages of the other options clarify why they do not represent a common downside. The lightweight and portable nature of oxyacetylene torches is, in fact, one of their key benefits, enabling operators to use them in various settings and locations. The suitability of oxyacetylene torches for thin materials is precisely the opposite concern; they may indeed be too powerful for these applications, potentially damaging the material. Lastly, while oxyacetylene systems do involve gas storage tanks, the size and storage requirements of the tanks are typically manageable and are not regarded as a significant disadvantage in the context of their functionality.