Thermal Spray, Hardfacing & Wear Coatings worked example

Grit Blast Prep Time at 7.2% fatigue and reposition allowance: a worked example

This worked example runs the grit blast prep time numbers for a tougher week than the baseline: 7.2% fatigue and reposition allowance instead of the typical 10%. Grit Blast Prep Time estimates how many booth hours it takes to bring parts to the anchor-tooth surface profile that thermal spray and hardfacing coatings need to bond.

The inputs for this scenario

  • Total surface area to grit blast: 120 units (held at the documented default)
  • Blast booth coverage rate: 12 units / hr (held at the documented default)
  • Fatigue / reposition allowance: 7.2 % (the input this scenario stresses; the baseline uses 10)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base grit blast prep time time = required work รท processing rate.
  • Adjusted run time works out to 10.72 hr at these inputs, and this is the headline figure for the scenario.
  • Base run time works out to 10 hr at these inputs.
  • Allowance applied works out to 7.2 % at these inputs.
  • Process rate works out to 12 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where fatigue and reposition allowance sits at 10% and the headline result is 11 hr, this scenario comes in 2.55% below the baseline at 10.72 hr.
  • Use it when scheduling the blast booth ahead of a spray run or quoting a job where surface prep is a large share of the work. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Adjusted run time: 10.72 hr (headline result)
  • Base run time: 10 hr
  • Allowance applied: 7.2 %
  • Process rate: 12 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Grit Blast Prep Time calculator, set fatigue and reposition allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.