The Prairie Doesn't Care About Your Flow Rate
In Rexburg, the frost lifts slowly. On the Black Hills ridge, the wind hits 45 mph before noon. At 10 mph, your argon blanket tears. At 20, the puddle oxidizes before you can drag the rod.
This calculator tells you when to stop. Inputs: wind speed, process type, nozzle diameter, and base flow. Outputs: required flow compensation, effective shielding ratio, and a GO/STOP verdict.
Grounded in: AWS D1.1 Section 6.2 (Field Welding Environmental Limits), ASME Section IX QW-442.2 (Gas Coverage).
How It Works
The model assumes turbulent boundary layer separation at the nozzle lip. Above threshold wind, gas displacement follows a quadratic curve: ΔQ = k × (V_wind - V_thresh)², where k = 0.15 CFH/(mph)² for argon mixtures. Shield effectiveness = Q_total / Q_required. Verdict flips to STOP when effectiveness drops below 0.65.
Constants stored in wind-factor.json: AWS limits, viscosity coefficients, and nozzle geometry factors.
A Story from the Ridge
I was welding a gate frame near Custer Peak last October. The forecast said 12 mph gusts. I had my 12mm nozzle, 20 CFH argon. By the third pass, the bead was gray—oxide creeping in from the north. I stopped. Set up a plywood baffle angled 30 degrees. Dropped the wind to 6 mph locally. Finished the joint in one hour.
The math didn't save me. The baffle did. But knowing when to build the baffle—that's what this calculator is for.