Blast Cost and Quoting

Blast Cost per Square Foot: Building a Four-Input Quote That Holds

A defensible quoting workflow using the V2 labor, energy, cost-per-area, rework, and margin calculators—each with four visible inputs and disclosed assumptions.

A reliable blasting quote starts with one written scope basis: accepted surface area, cleanliness and profile requirement, geometry class, access condition, number of loads or parts, planned shifts, and what counts as accepted work. Every downstream value must use that same basis. Mixing gross area in one calculator with inspected area in another is enough to create a clean-looking but incorrect cost per square foot. Record whether masking, rotation, containment, inspection, disposal, mobilization, and coating are included. The four-input calculators are intentionally quick, but their speed only helps when the estimator prevents scope from changing silently between pages.

Build direct labor with Blast Operator Labor Cost. Enter batch part count, setup elapsed hours, blast elapsed hours, and the loaded regular rate. The model applies disclosed crew, touch-time, and overtime assumptions to distinguish paid crew-hours from simple elapsed time. Use Blast Masking Time and Part Rotation Time to test whether preparation and handling are material enough to require separate labor lines. If those activities are already included in the entered blast elapsed hours or all non-labor direct cost, do not add them again. A transparent quote should say where each activity lives rather than hiding everything inside an unexplained shop rate.

Estimate the media and utility layers separately before consolidating them. Blast Media Consumption converts area, accepted rate, feed, and recovery into staged and replacement-media demand. Media Reclaim Value tests whether avoided purchase and disposal value exceeds reclaim operating cost. Blast Compressor Energy Cost multiplies loaded power by loaded hours and energy rate, then divides by accepted area. It deliberately represents marginal loaded energy under disclosed zero unloaded-power and demand-charge assumptions. If the quote must recover monthly demand charges, unloaded operation, diesel fuel, rental minimums, or a dedicated compressor package, add those costs to the non-labor direct-cost total with their basis stated.

Use Blast Cost per Square Foot only after labor and the non-labor stack are complete. Its four visible inputs are direct labor hours, loaded labor rate, all non-labor direct cost, and gross area. The non-labor entry is a consolidation field for media, energy, equipment, masking material, disposal, freight, containment, and other direct items that are not already in labor. The calculator applies its disclosed overhead and first-pass-yield assumptions to return total and accepted-area cost. If your accounting policy allocates overhead differently or your expected yield materially differs, document an external adjustment rather than pretending the default is plant-specific.

Rework belongs in the quote as risk, not as a guaranteed duplicate job. Blast Rework Cost asks for rework area, accepted blast rate, loaded labor rate, and event probability. Fixed setup, crew, media, energy, waste, and inspection assumptions complete the event-cost model. The full event cost answers what one failure would consume; probability-weighted exposure answers what should be carried across a portfolio of comparable jobs. Keep both numbers visible. Adding the full event cost to every quote overprices routine work, while carrying zero exposure assumes a level of first-pass control the process may not support.

Finish with Blast Quote Margin. Enter labor cost, all non-labor direct cost, overhead percentage, and quoted price. The non-labor field should contain the consolidated direct-cost stack once—never media in the consolidation field and again as a separate manual addition. The calculator applies its disclosed contingency basis, returns cost, profit, margin, and markup, and shows the price implied by the fixed target margin. Margin is profit divided by selling price; markup is profit divided by cost. Confusing the two is a direct pricing error, especially on jobs with expensive media, rental equipment, or disposal.

Run three saved cases instead of arguing over one point estimate. The operating case should use the best current evidence. The adverse case should reduce accepted coverage, recovery, and first-pass yield or increase event probability and handling burden. The improvement case should use only gains supported by trials or recent history. Compare quoted margin and cost per accepted square foot across all three. A quote is robust when the adverse case remains tolerable or the commercial terms explicitly protect the variables that can move. Sensitivity is more useful than padding every line with unrelated contingency.

Before release, reconcile the stack as if it were an invoice. Confirm labor hours times rate, the contents of non-labor direct cost, accepted versus gross area, media purchase quantity, loaded energy, expected rework exposure, overhead basis, contingency, quoted price, margin, and markup. Attach the downloaded workbooks or copy the disclosed assumptions into the estimate record. The calculators support planning and quote control; they do not replace contract review, environmental and disposal requirements, exposure controls, equipment limits, or a controlled costing policy. A defensible quote is one another estimator can reproduce from the same four-input pages.

Published 2026-07-01.