Galvanic Corrosion Prevention at Metal Connections

What galvanic corrosion means for metal connections

Galvanic corrosion occurs when two different metals are electrically connected and exposed to water or humid air. Each metal has a different position in the galvanic series, so one acts as an anode and corrodes more quickly while the other is protected. In architectural work this often shows up where stainless steel fixings meet galvanized steel, or where aluminum profiles touch steel brackets.

The effect depends on the environment. Rain, condensation, salty sea air and washing down of balconies all increase the risk. Dry interior locations are far less exposed, but the same principles apply.

Choosing compatible metals at the design stage

The simplest prevention is material selection. Pairs that are close together in the galvanic series create little driving force for corrosion, while widely separated pairs need more care. We recommend that designers review the metal combinations early, before drawings are final.

• Match fixings and washers to the base metal where possible.
• Avoid bare contact between copper-based materials and aluminum.
• Ask for the finish and coating system to be stated on the drawings.

Measurement and site survey

Before production, we visit the site to measure openings, levels and the exact points where different materials will meet. We note the surrounding conditions, such as direction of prevailing rain, proximity to the sea and any existing metal that must be connected. Photos and dimensions taken at this stage prevent guesswork later.

Where a new steel element must join an existing one, we check the current finish and condition so that the connection detail suits what is already there.

Drawings and written specification

Our drawings show each connection, the separating material, the fixing type and the sealant line. The written specification lists every metal, coating and fastener so that the architect or contractor can approve it before work begins. Clear details protect both the designer and the client.

What we include

• Each metal combination and its contact points
• Insulating layers such as neoprene, PTFE tape or coated washers
• Sealing and drainage details

Production and finishing in our workshop

In the factory at 37 Rival Street, we cut, weld and assemble components to the approved drawings. Where galvanic separation is required, we fit insulating sleeves and washers during assembly rather than leaving them to the installer. Finishing, such as hot-dip galvanizing or powder coating, is applied to the assembled parts where it protects the joints best.

We check that coatings are continuous at weld areas and cut edges, since these are common starting points for corrosion.

Installation and long-term care

On site, our team installs the elements with the same separation details used in production. Fixings are tightened to the specified torque, and sealants are applied to keep water away from the contact line. Any damaged coating from transport or fitting is touched up before handover.

We advise owners to rinse exposed metal periodically, especially near the sea, and to inspect joints once a year. Early attention to a small coating scratch is far cheaper than repairing a corroded connection.

Frequently asked questions

Can stainless steel and galvanized steel be used together?

Yes, but the contact point should be separated with an insulating washer or sleeve and sealed against water. Without this, the galvanized steel may corrode faster at the joint.

Does galvanic corrosion only happen outdoors?

No, it can occur indoors wherever moisture or condensation is present, such as in bathrooms or near kitchen areas. Outdoor and coastal locations simply increase the risk.

Do I need to tell you about the metals in my project?

Yes, please share the drawings or describe each metal and finish so we can plan the separation details before production begins.

How do I know if my connection is at risk?

Look for white or brown deposits, bubbling paint or pitting near where two metals meet. If you see these signs, we can inspect the joint and suggest a suitable repair.

Common mistakes to avoid

The most common error is connecting two dissimilar metals directly without insulation or sealing, and leaving the finish unspecified until installation. Both can be avoided by stating the metals and separation details on the drawings from the start.

Our recommendation

Specify the metal pairs, insulating material and sealant line on every connection detail, and ask for the coating system to be confirmed before production. A few minutes of detailing at the design stage prevents years of maintenance.

Summary

Galvanic corrosion at metal connections is preventable through careful material selection, insulation, sealing and clear specification. Our measurement, drawing, production and installation process is built around these steps.

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