What should one use for non-porous smooth finish?

Using a steel trowel is ideal for achieving a non-porous smooth finish. The steel trowel provides a firm, flat surface that allows for precise application and finishing of materials such as plaster or concrete. When used correctly, it compacts the surface and eliminates air pockets, resulting in a smooth, polished appearance that is easy to clean and maintain.

This method is particularly effective for applications where a seamless and uniform surface is desired, making it popular in both residential and commercial projects. A smooth finish not only enhances the aesthetics of the surface but also provides a durable layer that resists moisture infiltration and staining.

In contrast, other options do not provide the same level of smoothness or are intended for different finishes. For instance, perlite is a lightweight aggregate that is used for insulation or as a lightweight filler but does not contribute to a smooth finish. Blown-on acoustic finishes are designed primarily for sound absorption rather than creating a smooth surface, and floated sand plaster, while useful for texture, will not yield a non-porous smooth finish as effectively as a steel trowel would.