By material
Aluminum is not steel with a different setting. Its oxide layer melts far hotter than the metal underneath, so TIG requires alternating current, and MIG requires wire that will feed without buckling. Everything else follows from those two facts.
Aluminum is not steel with a different setting. Its oxide layer melts far hotter than the metal underneath, so TIG requires alternating current, and MIG requires wire that will feed without buckling. Everything else follows from those two facts.
The hardest case: the alloy is unknown and often full of impurities. The area has to be cleaned mechanically and the filler chosen with care.
The favorable case: known alloy, even thickness, preparation possible. MIG with a spool gun is efficient here.
Aluminum conducts heat far faster than steel and does not glow before it collapses. AC TIG gives the control you need.
AC TIG is the only process that gives a presentable aluminum bead with no rework.
| What you weld | The process | What else you need |
|---|---|---|
| Extrusions, medium thickness | MIG with a spool gun | Wire matched to the alloy, argon |
| Thin sheet, visible bead | AC TIG | Suitable tungsten, argon, patience |
| Casting repair | AC TIG | Mechanical cleaning, chosen filler |
| Non-structural repair | Low-temperature brazing | Knowing it is not welding |
Aluminum is demanding on consumables: wire oxidizes in store, tungsten contaminates at the first touch of the pool, and the liner fills with soft particles. Bead consistency follows the state of those three directly.
The same risks as for steel, with two particularities: radiation is more intense on alternating current, and fine aluminum dust is flammable.
200 A AC/DC · HF start · 12.7 kg (28 lb) · €300
The cheapest AC/DC machine here, which is to say the cheapest one that can weld aluminum at all.
Best for: A first AC/DC machine, bought because aluminum is somewhere in the plan
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
200 A · pulse and double pulse · aluminum synergics · €600
The only machine here with genuine pulse and a spool gun interface — which is what makes aluminum a normal job rather than a fight.
Best for: Aluminum work, and anyone who wants the weld to look like the ones in the photographs
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
No. Direct current cannot break the oxide layer, and no gas, tungsten or technique substitutes for it. This is the single hardest limit in welding, and it is why AC/DC machines cost more. If aluminum is anywhere in your plans, buy AC now — it cannot be added later.
Because it is soft. Steel wire is stiff enough to push four meters down a liner; aluminum compresses and coils behind the drive rollers. The fixes, in order: a spool gun with the spool in the handle, a Teflon liner with U-groove rollers, or a very short torch.
On heavy sections, often yes, because the metal sheds heat faster than it arrives. Preheat stays moderate: too hot and aluminum loses its strength and collapses with no warning.
Without a marking, you cannot know for certain. Commercial extrusions are generally weldable alloys; castings are far less predictable. In doubt, a test on a hidden area is the only real check.
Argon in the great majority of cases. Helium mixes exist to raise heat input on heavy sections, with a different cost and a different set-up.
That points to a lack of gas shielding or a poorly prepared surface. Check flow, nozzle and drafts, then the cleaning: the oxide re-forms within minutes.
On non-structural repairs and lightly loaded parts it is useful. It does not replace a weld on something that works, and presenting it otherwise would be misleading.
That is the setting that trades oxide cleaning against penetration. Without it you work with a fixed compromise: possible, but less fine on thin sheet and less clean on oxidized parts.
For work that: A first AC/DC machine, bought because aluminum is somewhere in the plan
Where it is best: AC mode breaks the oxide layer, so aluminum is genuinely on the menu
Where it is worst: 12.7 kg (28 lb) — the heaviest machine in this price band here
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: Aluminum work, and anyone who wants the weld to look like the ones in the photographs
Where it is best: Pulse and double pulse, with aluminum synergic programs — the reason to buy it
Where it is worst: €600 buys 200 A here and 200 A elsewhere for half that — you are paying for pulse
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.
