Aluminum welding: what it takes to get it right

Aluminum welding for buyers: why it is harder than steel, TIG vs MIG spool gun, which grades weld (and which do not), and how to spec an aluminum weldment.

Quick answer: Aluminum welding is TIG for most work, or MIG with a spool gun for thicker sections. It is less forgiving than steel: aluminum pulls heat away fast, oxidizes instantly, and gives no colour warning before it collapses. Weldable grades include 5052, 6061 and 6063; 7075 and most castings do not weld well. For a structural aluminum weldment, spec TIG, a weldable grade, and CWB certification to CSA W47.2 if it is load-bearing.

Why aluminum is harder than steel

Aluminum does not turn red before it melts. It gives no warning, then it is a puddle on the floor. It conducts heat away from the weld fast, so it needs more heat input and a skilled hand, and its oxide layer melts far hotter than the metal underneath, so the surface has to be clean. That is why aluminum TIG is a skill you pay for and steel MIG is a skill you assume.

TIG or MIG for aluminum

TIG for most work: it is precise, clean and controls the heat, which is what aluminum demands. MIG with a spool gun (which feeds soft aluminum wire without birdnesting) is faster on thick sections and production runs. For thin material, food and pharma, and anything visible, TIG is the answer. See the full process trade in MIG vs TIG welding.

Grade decides whether it welds at all

5052, 6061 and 6063 weld well and cover most fabricated aluminum. 7075 does not: it cracks and loses strength in the weld zone, so drop the idea of welding it now, and a shop that agrees to weld 7075 is telling you something about the shop. If your part is 7075, redesign it in 6061 or fasten it mechanically. The grade trade is in 6061 vs 7075 aluminum.

Certification for structural aluminum

Load-bearing aluminum welding in Canada falls under CWB certification to CSA Standard W47.2, the aluminum companion to W47.1 for steel. If your weldment is structural, spec it, and we route only to shops that hold it. Process and food aluminum TIG work is common in markets like Edmonton.

What to send for a quote

Grade and thickness, whether the weld is structural, sealed or cosmetic, any finish, certification requirements, and quantity. Request quotes and we match you to Canadian welding shops that weld aluminum regularly.

FAQ

Can you weld aluminum?

Yes, with the right process and a skilled welder. TIG for most work, MIG with a spool gun for thick sections, and a weldable grade (5052, 6061, 6063). It is harder than steel but routine for shops set up for it.

TIG or MIG for aluminum?

TIG for precision, thin material and appearance; MIG with a spool gun for speed on thicker sections and production. Most custom aluminum weldments are TIG.

Can you weld 7075 aluminum?

Not readily. 7075 cracks and loses strength when welded, so it is joined mechanically instead. Use 6061 or 5052 if the part must be welded.

Why is aluminum harder to weld than steel?

It conducts heat away fast, oxidizes instantly, and gives no colour change before melting, so it needs more heat, clean material and a practiced hand. Steel is far more forgiving.

Do I need certified aluminum welding?

For structural and load-bearing work, generally yes, to CWB and CSA W47.2. For non-structural parts, often not. Tell us the job and we route accordingly.

Last reviewed: July 2026. Related reading: MIG vs TIG welding and 6061 vs 7075 aluminum.