Aluminium turns up everywhere once you start looking: boat trailers, tinnies, pontoons, ute trays, toolboxes, water tanks and plenty of farm and river gear. It is light and it does not rust like steel, but when it cracks, a lot of welders will not touch it. We weld aluminium on site with the mobile rig, as part of our MIG and TIG work alongside steel and stainless, across the Adelaide Hills, the Barossa, the Murraylands and Adelaide.
Why aluminium is a different job to steel
If you have only ever had steel welded, aluminium can seem fussy. There are good reasons for that:
- It carries heat away fast. Aluminium spreads heat through the part much quicker than steel, so the welder has to put the heat in quickly and control it the whole way along.
- It has a tough oxide skin. The surface oxide melts at a far higher temperature than the metal underneath, so the joint has to be cleaned back to bright metal before welding.
- It gives no warning. Aluminium does not glow red before it melts like steel does, which is why it takes practice to weld well.
- Some alloys lose strength near the weld. Many structural aluminium sections are heat treated, and the metal right next to a weld ends up softer than the rest. A good repair allows for that, often with a doubler plate or by moving the joint away from the highest-stress spot.
None of that makes alloy repairs rare or risky. It just means the welder needs the right process, clean metal and some idea of what the part does.
Alloy repairs we do on site
The rig carries the welder, a generator and the cutting gear, so most of these jobs are done where the gear sits, in the driveway, the shed or at the riverbank:
- Boat trailers. Cracked drawbars, broken roller and skid brackets, torn mudguard mounts and worn fittings on alloy and galvanised trailers.
- Boats and pontoons. Cracked brackets, rails and fittings, plus repairs to pontoon frames and tinnies. Tell us where the crack is and whether it is above or below the waterline.
- Ute trays and canopies. Cracked tray frames, headboards, side rails and toolbox mounts. Alloy trays shake hard on corrugated roads and farm tracks, and they tend to crack at the corners and mounts.
- Toolboxes and racks. Hinges, lid frames, mounting brackets and ladder racks.
- Tanks. Alloy water tanks and tanks that have held fuel. A fuel tank has to be emptied, cleaned and made safe before anyone welds it, so always tell us what it has held.
- One-off alloy parts. Brackets, frames and light fabrication made to suit, from our Mount Pleasant workshop if it is easier to build there.
We weld steel and stainless too, so if the job is an alloy toolbox on a steel tray, or a galvanised boat trailer with alloy fittings, it is all done in one visit. See our welding repairs page for the rest of the repair work we do.
Repair it or replace the part?
Most cracks in alloy trailers, trays and toolboxes can be repaired. A crack is ground out, cleaned and welded, and plate is added where the part needs more strength. It is worth asking about a replacement part instead when:
- The aluminium has thinned out from corrosion, often where salt water has sat against steel bolts or brackets.
- The part has cracked again in the same place after an earlier repair, which usually means the design needs changing, not just another weld.
- It is a cast alloy part with a lot of damage, where a new part can cost less than the repair.
Send a photo and we will tell you straight which way we would go. If a boat trailer has other damage, like a cracked chassis or a rotten floor, our guide to trailer repairs covers what we look for.
What to tell us before we come out
A few details mean we turn up with the right process and consumables the first time:
- What the part is (boat trailer, tinny, ute tray, toolbox, tank) and roughly how old it is.
- Clear photos of the crack or damage, plus one of the whole item.
- The thickness of the metal if you know it, and whether it has been welded before.
- Whether it is in salt water, fresh water or neither, and what a tank has held.
- Where it is and whether it can be moved under cover.
Send it through our contact form or call Sean on 0455 579 207. We are based in Mount Pleasant and work Monday to Saturday, 7am to 5pm, across the Adelaide Hills, the Barossa, Mannum, Murray Bridge and the river, and Adelaide. Quotes are free.
Common Questions
Do you do aluminium welding on site?
Yes. We weld aluminium on site with the mobile rig, as part of our MIG and TIG work alongside steel and stainless. Boat trailers, ute trays, toolboxes, pontoons and tanks are all regular jobs.
Can a cracked aluminium boat trailer be welded?
Usually, yes. Cracked drawbars, brackets and fittings on alloy boat trailers are ground out, welded and plated where needed. Send a photo of the damage and one of the whole trailer and we will tell you what it takes.
Do you weld aluminium boats and pontoons?
Yes. We do boat, pontoon, tank and fuel-cell repairs and light alloy fabrication. Let us know the alloy and thickness if you know them, and where the damage is.
Where do you do aluminium welding?
We are based in Mount Pleasant and travel across the Adelaide Hills, the Barossa, the Murraylands and the river towns, and Adelaide. Bigger alloy fabrication can be built in our Mount Pleasant workshop.
