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Formula used
This calculator estimates a recommended shielding gas setpoint in CFH using a base flow related to nozzle/cup diameter, then applies adjustment factors for gas type, location, draft, and access.
- MIG base: BaseCFH = 1.2 × Diameter(mm) + 5
- TIG base: BaseCFH = 0.9 × Diameter(mm) + 2
- Setpoint: SetpointCFH = BaseCFH × GasFactor × LocationFactor × DraftFactor × AngleFactor
- Range: ±20% around setpoint, clamped to sensible limits
- Conversion: L/min = CFH × 0.4719
How to use this calculator
- Select MIG or TIG for your garden fabrication task.
- Pick your shielding gas and enter nozzle or cup diameter.
- Choose location and draft level where you will weld.
- If access is tight, select awkward access for a safety bump.
- Press calculate, then set your regulator to the recommended range.
Example data table
| Process | Gas | Diameter (mm) | Location | Draft | Recommended (CFH) | Range (CFH) |
|---|---|---|---|---|---|---|
| MIG | Argon/CO₂ Mix | 14 | Indoor | None | ~23 | ~18–28 |
| MIG | CO₂ | 16 | Outdoor (sheltered) | Light | ~35 | ~28–42 |
| TIG | Argon | 12 | Indoor | None | ~13 | ~10–16 |
| TIG | Helium Mix | 14 | Outdoor (breezy) | Moderate | ~30 | ~24–30 |
Examples are illustrative; tune based on your weld appearance and conditions.
Shielding gas in outdoor garden fabrication
Garden gates, trellis frames, and planter stands are often welded in open air where wind strips away shielding. This calculator translates torch setup and site conditions into a practical flow target, helping you keep a stable weld pool and consistent bead profile without overusing gas. Stable shielding also improves color on stainless garden hardware and reduces post weld cleanup.
How process choice changes flow needs
MIG typically uses a larger nozzle and higher deposition rate, so the recommended flow band is higher than TIG. TIG relies on a focused cup and precise arc control, so too much flow can create turbulence and pull in oxygen. Selecting the correct process sets sensible minimums and maximums. For thin sheet, lower flow with better coverage often beats higher flow with turbulence at the cup.
Diameter driven baseline and adjustment factors
The model starts with a diameter based baseline in cubic feet per hour, then multiplies by factors for gas type, location exposure, draft intensity, and awkward torch access. Helium mixes and breezy outdoor work raise the requirement, while calm indoor work stays closer to the base. The result is clamped to realistic limits to prevent extreme settings.
Interpreting the recommended range on the regulator
Use the setpoint as your starting value, then fine tune within the range while observing weld quality. Signs you may need more flow include porosity, soot, and a dull, oxidized appearance. Signs of excessive flow include a noisy arc, wandering shielding, and visible turbulence at the nozzle. Always check hoses and fittings for leaks before increasing flow.
Good practice checklist for repeatable results
Position your work to block cross drafts, use temporary screens, and keep your nozzle or cup clean. Maintain appropriate stick out, hold a steady travel speed, and avoid swinging the torch away from the puddle. Record the final flow and conditions using the CSV or PDF export so you can repeat settings for similar garden projects and reduce refill surprises.
FAQs
What gas flow unit should I use, CFH or L/min?
Many regulators show CFH, while some charts use L/min. This tool outputs both. Use the setpoint first, then adjust within the range after checking bead appearance and porosity.
Why does outdoor welding require higher flow?
Wind and cross drafts dilute the shielding envelope around the arc. Higher flow helps maintain coverage, but a screen is usually more effective than turning the regulator up too far.
Can I fix porosity by only increasing flow?
Sometimes, but first check for leaks, empty cylinders, contaminated surfaces, or long stick out. Increase flow in small steps within the suggested band and confirm the arc is not becoming turbulent.
Does nozzle or cup size matter that much?
Yes. A larger diameter needs more volume to fill the shielding area, while a small cup can become unstable if flow is excessive. Diameter is the baseline driver in the formula.
Why is helium shown with a higher factor?
Helium is lighter and diffuses differently than argon based mixes, so it often needs more flow to maintain shielding, especially outdoors. Start at the setpoint and fine tune.
How do I save results for repeat jobs?
After you calculate, use the CSV or PDF buttons. Keep notes on metal thickness, wind conditions, and your final dialed setting to repeat successful parameters on future garden builds.