Aluminium is light, corrosion-resistant and ideal for Cape Town’s coastal conditions — but it is one of the hardest metals to weld properly. It conducts heat fast, has no colour change before it melts, and forms an oxide layer that has to be cleaned off before a weld will hold. Get it wrong and the joint cracks or burns through.
We weld aluminium at our workshop and on site across Cape Town, for everything from window and door frames to gates, balustrades, brackets and custom components.
Frames, doors and windows. Repairs to existing aluminium frames, plus custom-built frames where a standard size will not fit. Corner joints and mitres are the usual failure point on older frames.
Gates and balustrades. Aluminium is a strong choice near the sea because it will not rust the way mild steel does. It is lighter than steel, which matters on large swing gates.
Brackets, covers and custom parts. One-off components, machine guards, panels and mounting brackets fabricated to your measurements.
Repairs to cast and extruded aluminium. Cracked housings, broken mounts and damaged sections that would otherwise mean replacing the whole item.
Aluminium behaves nothing like mild steel under heat. It melts at a much lower temperature but conducts heat away from the weld far faster, so the settings and technique have to compensate for both at once. There is also no visual warning — steel glows before it melts, aluminium simply collapses.
The oxide layer is the other issue. Aluminium oxide melts at roughly three times the temperature of the metal underneath it, so the surface has to be cleaned back properly before welding or the joint will be contaminated. This is why a general welder who mostly runs mild steel will often struggle with aluminium.
We use TIG for aluminium work where finish and control matter. If you want the detail on how the processes differ, see our guide to TIG vs arc welding.
Both resist corrosion, and both cost more than mild steel. Aluminium is far lighter and easier to work at larger sizes, which makes it the usual pick for window frames, doors and big gates. Stainless is harder, holds an edge and takes a polished finish better, which is why it wins for balustrades, handrails and anything in a kitchen or food environment.
Our comparison of aluminium and stainless steel welding goes into where each one earns its cost.
New fabrication is better done in the workshop, where the piece can be held square in a jig and the conditions are controlled — aluminium TIG work in particular suffers in wind, because the gas shielding gets blown off the weld pool.
Repairs to something already fitted — a frame in a wall, a gate on its hinges — are usually done in place. See on-site welding in Cape Town for what we can handle without removing the item.
Aluminium work carries a higher rate than mild steel. The metal itself costs more, TIG is slower than arc welding, and the preparation takes longer. Against that, aluminium needs no galvanising or painting to survive near the coast, so the lifetime cost on an exterior job often comes out lower.
The real variables are the thickness of the material, how much cleaning and preparation the joint needs, and whether the work happens here or at your property. For a breakdown of how welding is priced generally, see our welding cost guide.
Not directly with standard welding. The two metals have very different melting points and form a brittle compound where they meet, so a joint made this way fails. Where the two need to connect, we use mechanical fixings or a bimetallic transition instead.
The most common causes are contamination from an uncleaned oxide layer, the wrong filler alloy for the parent metal, or heat input that was too high for the section thickness. Cracking on a repair usually means the underlying cause was never addressed.
Yes, provided the section sizes are specified for the span and weight. Aluminium is lighter than steel, which reduces load on hinges and motors, but the frame design has to account for it being less rigid than steel section for section.
If a previous weld failed, see why aluminium welds crack.
