You need to polish hypertufa if you want a smooth finish on the fabricated stone. The cementitious material wet-molds readily into a variety of garden containers and ornamental features due to the constituents of hypertufa, such as peat moss and perlite. An unfinished hypertufa surface feels rough to the touch, so polishing the object removes the potential for grazes. Polishing hypertufa also creates an aesthetic by changing the style from a rustic look to a sleek design.
Use a metal file or rotary tool with a grinding pad to grind off any misshapen protrusions from the hypertufa surface. Use a pull-and-push motion with the file when grinding imperfections from the surface. Take care not to let the file or rotary tool slip onto the surrounding area.
Rub the hypertufa with coarse-grit sandpaper to flatten large surface granulation. Apply up-and-down and side-to-side movements with the sandpaper to ensure an even surface texture. Sweep any hypertufa dust from the object using a hand brush.
Use medium-grit sandpaper to further polish the hypertufa and flatten minor surface granulation.
Polish the surface with fine-grit sandpaper to create a smooth finish. Sand the hypertufa in a circular motion to produce a uniform appearance.
Clean the sanding dust from the hypertufa with a hand brush. Rinse the object with cold water to remove dust residue, and allow the hypertufa to dry.