When using a magnesium bull float, leaving a small unfloated section and waiting for bleed water in that section can help determine if the magnesium float is ________ the surface.

When using a magnesium bull float, leaving a small unfloated section and waiting for bleed water in that section can help determine if the magnesium float is ________ the surface.

• A. Sealing
• B. Smoothing
• C. Polishing
• D. Cleaning

Answer: (A)

Bleed-water behavior is the clue you use to see if the surface is being sealed by the bull float. When a magnesium bull float is used, it pushes some of the cement paste into the surface pores and can seal them, which reduces or stops bleed water from rising. By leaving a small unfloated patch and watching for bleed water there, you’re testing whether the surface in that patch is sealed. If bleed water shows up in the unfloated area, the surface isn’t sealed yet by the float. If no bleed water appears, that indicates the float has sealed the surface in that patch. So this check specifically gauges sealing of the surface. The other finish actions—smoothing, polishing, cleaning—aren’t what this bleed-water test is assessing.

Bleed-water behavior is the clue you use to see if the surface is being sealed by the bull float. When a magnesium bull float is used, it pushes some of the cement paste into the surface pores and can seal them, which reduces or stops bleed water from rising. By leaving a small unfloated patch and watching for bleed water there, you’re testing whether the surface in that patch is sealed. If bleed water shows up in the unfloated area, the surface isn’t sealed yet by the float. If no bleed water appears, that indicates the float has sealed the surface in that patch. So this check specifically gauges sealing of the surface. The other finish actions—smoothing, polishing, cleaning—aren’t what this bleed-water test is assessing.