The phrase "below the sand surface" is correct and usable in written English.
For example, "The archeologists carefully dug below the sand surface to find any artifacts."
Clean off the sanded surface with a clean, dry rag.
Prime the sanded surfaces.
Strong anaerobic conditions with oxidation reduction potential −320 mV were self-developed at 5 6 cm depth below sand surface by bacterial community.
Salmonella spp. were isolated from surface and deep (as far as 50 cm below the surface) sand samples.
Below the sand are Paleozoic rocks of the Perth Basin.
The interior of the Arabian Peninsula contains extensive sand surfaces.
We detected very high concentrations of H2 at the bottom of the peat, 3 4 m below the ground surface, in clayey sand.
The cyanobacteria, which live less than 1 millimeter below the rock surface, tend to turn sand into rock in two ways, says Kurtz: They grow filaments that attach to the sand grains, and they produce acidic polysaccharides--sticky starches with a consistency resembling pasty glue.
Sand the surface of the parts with a dual action sander, using 80-grit sanding discs.
