Gas
Shielding gas is the least visible part of a weld and the easiest to get wrong. The three things that matter are the mixture, the flow rate, and whether the system leaks — and the last one costs people a full cylinder more often than any other mistake.
Shielding gas is the least visible part of a weld and the easiest to get wrong. The three things that matter are the mixture, the flow rate, and whether the system leaks — and the last one costs people a full cylinder more often than any other mistake.
A medium bottle, a two-gauge regulator, and a flow set once for the torch in use.
A small bottle travels, stores and swaps quickly; it also empties quickly, which makes leak checking pay for itself sooner.
On a visible bead, the steadiness of the gas reads in the pool. That is where an intermittent leak shows before it is heard.
Two gases, so two bottles or a serious purge. Residue from the previous mix turns up in the first few centimeters of bead.
| Process and metal | Usual gas | What it changes |
|---|---|---|
| MIG on steel | Argon–CO₂ mix | A compromise between penetration and cleanliness |
| MIG on steel, penetration | Pure CO₂ | More penetration, more spatter |
| MIG on stainless | Stainless-specific mix | Corrosion resistance of the bead |
| TIG, common metals | Pure argon | A stable pool and a controllable arc |
A gas set-up is maintained at its fittings and its nozzle, never inside the regulator. A gauge that will not return to zero, a perished seal or a fouled nozzle explain almost every shielding fault.
A pressurized gas bottle is the one object in the workshop that can become a projectile. The gas itself is not toxic in these uses, but it displaces oxygen in a closed room.
200 A · synergic · gas and gasless · €330
The synergic 200 A inverter that most German workshops end up with, and the cheapest machine here with a genuinely adjustable inductance.
Best for: A first serious MIG that will still be adequate after two years of use
160 A · 230 V single phase · Euro torch connector · €505
A French-built trolley machine with a Euro connector and a 40 W feed motor — bought for the feed quality rather than for its headline current.
Best for: Someone who intends to keep the machine ten years and wants standard consumables
200 A AC/DC · AC frequency 20–100 Hz · spot 0.01–9.99 s · €459
The first machine on this page that publishes its AC frequency range and pulse frequencies — the controls aluminum actually needs.
Best for: Aluminum work where the arc has to be steered, not just switched on
10–200 A TIG · 10–170 A MMA · 9.5 kg (20.9 lb) · €460
The only machine here that publishes a current range starting at 10 A — and the lightest AC/DC on the page at 9.5 kg (20.9 lb).
Best for: Thin stainless and aluminum, and anyone who has to carry the machine upstairs
Around 8 to 12 l/min for MIG with a standard nozzle, often less for TIG with a gas lens. More is not better: beyond a certain flow the shield becomes turbulent and pulls air in, producing porosity that looks exactly like too little gas — which is why people then turn it up further and make it worse.
Soapy water on every joint, cylinder open, torch closed. Bubbles mean a leak. It takes two minutes and it is the difference between a cylinder lasting months and emptying itself overnight. Do it every time a connection is disturbed.
Yes on steel: it penetrates more and costs less, at the price of more spatter and a less even bead. Many machines take it, provided you adjust the settings.
The bead turns porous and grey, and the fault shows immediately. It is a structural defect: the area is ground out and redone, not fixed by running over it again.
Rental charges a standing fee but guarantees exchange; buying with a deposit removes the fee but sometimes narrows where you can swap. The sum depends on annual usage, and is worth redoing after a few years.
It depends on flow, nozzle diameter and above all on real arc time, which is far shorter than people imagine. No honest order of magnitude can be given without those three.
Yes, briefly: air that entered the hose during the change otherwise produces a few centimeters of porous bead. A few seconds of purge is enough.
On CO₂ at high flow, the expansion cools sharply and frost can appear. It is a sign of high flow; reduce it and let the temperature recover rather than heating the regulator.
For work that: A first serious MIG that will still be adequate after two years of use
Where it is best: Synergic control: you set the material and thickness, the machine sets the wire speed
Where it is worst: The duty cycle is not stated with its temperature in the listing, so 200 A is a ceiling, not a working figure
For work that: Someone who intends to keep the machine ten years and wants standard consumables
Where it is best: Euro central connector: torches, liners and tips are standard parts you can buy anywhere
Where it is worst: Costs roughly double the 160 A inverters, for the same headline current
For work that: Aluminum work where the arc has to be steered, not just switched on
Where it is best: AC frequency adjustable from 20 to 100 Hz — this is what focuses the arc on aluminum
Where it is worst: €459 — the point at which a TIG machine stops being an impulse purchase
For work that: Thin stainless and aluminum, and anyone who has to carry the machine upstairs
Where it is best: A published lower limit of 10 A — the figure that decides what you can do on foil-thin stainless
Where it is worst: « High duty cycle » is claimed without a number, which is the one place the sheet goes vague
Tips, nozzles, wire and gas from the same aisle, at the price we read. Confirm they suit the machine you choose before ordering: it turns on the torch and the part number, which the product page gives.
Welder against welder, where the comparison is already written up.
The welders here are taken from the catalog of this site. Specifications come from the maker and from the Amazon product page; prices are what Keepa reported for the date shown, and both move. The order rests on declared specifications, on stated strengths against stated limits, and on price. No machine here has struck an arc in our hands, and nothing on this page pretends it has.
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Prices quoted in these summaries are dated readings. The live price is shown next to each product.
Welders and plasma cutters swing by a hundred dollars or more across the year, and the biggest "discounts" often land at prices the same model sold for six weeks earlier. UniverTrack tracks the real price history across retailers, spots fake reductions, and alerts you when it is genuinely the moment to buy.
