At Wrightstyle, we make all our glazing systems from steel, and every piece of steel is Sendzimir-galvanised.
Like all galvanising methods, this involves coating the steel with a protective zinc layer to ward off rust and corrosion.
So, why do we use Sendzimir galvanising – and why is it important for glazing and glazing systems in particular?
The simple answer is that it protects against corrosion without adding much thickness or changing the shape of the steel. This improves aesthetics and longevity and reduces the risk of spontaneous glass breakage.
Named after the engineer Tadeusz Sendzimir, it involves passing a continuous coil of steel through a furnace. Oils are burned off, and oxides are minimised. The steel is then put in a bath of molten zinc.
The result is a steel frame with a smooth and uniform surface, superior protection against corrosion and structural stability. All these perks are good for the frame and good for the glass that goes in it.
Why is Sendzimir galvanising good for glass?
Framing glass presents several engineering problems – problems that Sendzimir galvanising helps solve.
It reduces pressure points
First, there's the fact that traditional hot-dip galvanising can create a rough and uneven texture, spikes of zinc or pooling.
This unevenness can create pressure points, increasing the chance of spontaneous glass breakage within the frame.
Sendzimir galvanising fixes this problem by wiping off excess zinc. The finished product is flat and polished, and the weight of the glass in the frame is evenly distributed against gaskets and seals.
It helps prevent cracking
Traditional galvanising can create a thick and brittle iron-zinc alloy layer. When the frame is assembled, this can flake or crack, ruining the seal and trapping moisture.
The Sendzimir galvanising process avoids this by adding aluminium to the zinc bath. This removes the iron-zinc alloy layer. The galvanised steel can then be bent, roll-formed and cut into intricate shapes without cracking or flaking.
It allows for attractive, durable finishes
Sendzimir galvanising provides an excellent substrate for high-quality powder coating – something that's difficult to achieve with standard galvanised steel without chemical etching. This gives architects a frame with a clean powder-coated finish.
It's self-healing
Glass frames are vulnerable to trapped moisture from condensation, rain and humidity. Sendzimir steel utilises something called "sacrificial cathodic protection".
This means the zinc seals the edge exposed by a scratch or cut. This stops rust from creeping into the seals and helps prevent structural damage.
What is the science behind Sendzimir galvanising?
Sendzimir galvanising begins with a cleaning process. Oil, grease, dirt and iron oxides are removed from the steel strips, enabling them to bond to the zinc.
The strip is then heated in a controlled atmosphere. This atmosphere often contains hydrogen and nitrogen. This process reduces surface oxides and gets the steel ready for coating.
Next, the steel strip is passed continuously through a bath of molten zinc. When it comes out of the bath, the steel has a layer of liquid zinc.
This layer isn't like a layer of paint. Instead, the iron and zinc interact to create a solid-state compound called an intermetallic phase.
The strip is then passed between air knives. These tools blow the excess molten zinc off the sheet. The manufacturer can control this process to ensure the right coating thickness. As we say, the thinness of the layer is part of what makes Sendzimir galvanising good for glazing systems.
The zinc protects the steel thanks to its superior electrochemical activity. When the galvanised steel comes into contact with moisture, the zinc corrodes first. And if the coating is scratched, the surrounding zinc can protect the exposed steel.
Why choose Sendzimir-galvanised steel glazing systems?
At Wrightstyle, we exclusively use Sendzimir-galvanised steel for our glazing systems. It provides a clean, narrow profile while protecting against corrosion from contact with condensation, rain and humidity.
It's galvanised as a continuous coil, meaning it can be roll-formed or pressed into the profiles you need for your glazing systems.
And because the galvanising coats the steel strip before it's fully formed, Sendzimir galvanising ensures high-quality and consistent coverage and protection.
It also increases the glazing system's longevity. That's because it helps the steel frame, brackets, channels and other components maintain structural soundness for longer than other kinds of galvanising.
It also protects against aesthetic damage. Rust can migrate onto nearby glass, seals and finishes. Sendzimir galvanising reduces this risk.
Finally, Sendzimir galvanising is cost-effective, reducing the overall price of each unit. This is because it provides comprehensive coverage rather than individual component treatment.
How Sendzimir galvanising supports specialist applications
At Wrightstyle, we provide specialist glazing systems, including
fire-resistant,
ballistic-resistant and
bomb-resistant systems.
Sendzimir galvanising supports the rigorous testing requirements needed for these specialist applications with no compromise to the integrity of the metal. In the case of fire resistance, this helps us provide fire protection for up to 180 minutes.
Your questions answered:
