Aluminium is one of the most resistant materials in existence. But, when put in a humid atmosphere, it tarnishes to a point that depends on the medium. The same happens when you expose it to fresh or salt water. We refer to this phenomenon as blackening or water staining. It isn’t a form of corrosion. Instead, it is only an alteration of the visual characteristics of the natural oxide film. It does not create any subsequent corrosion sensitivity. As one of the top suppliers of 5754 (H111) aluminium sheet and coil in the UK, we want to have a closer look at the issue and how to prevent it.
Why does water staining happen?
If there is water on aluminium, it can become trapped between the sheets, wraps, or other packaging material. There won’t be any air flow to remove it. Due to the extensive contact between the metal and water, there will be a chemical reaction. The result will be water staining. It could manifest as dark stains or white marks. It can happen rapidly, even with new metals. Since this is the case, you need to act quickly if you find moisture around or on your aluminium.
Additionally, condensation can contribute here. It becomes present when you remove metal from cold or cool storage into a warm truck during a humid day. This can happen at any point in the year. For some areas, things can be more problematic in the summer.
Storing aluminium
When you store the metal, it is suggested that you don’t leave warehouse doors open. You should do this whether you have 5754 (H111) aluminium sheet and coil or any other grade.
It is particularly important to be careful during spring and autumn. These are the periods where there will be big temperature differences between the day and night. When it is dark, cold air gets in and begins cooling your metal. During the day, if air humidity and temperatures increase swiftly, the dew point will rise too. Aluminium’s temperature rises more slowly though. That sets things up where water condenses on the exterior.
Keep in mind that this process isn’t just going to happen in warm months. It will occur when there are big enough humidity and temperature changes. They are very common in the UK.
Avoiding water staining
For starters, don’t leave goods stored and packaged outside. If you need to leave anything here before installation, unpack your items and separate them onto timber. This way, no two pieces of aluminium are in contact.
In storage, avoid putting aluminium with other metals. Employ wood faced shelving, bins, and racks. Store things away from acids, phosphates, nitrates, and caustics too. Ensure you also use the older stock first.
Upon receipt of any deliveries, examine materials for indications of wetness. This will let you halt the possibility of moisture staining. Be on the lookout for wet pallets and packaging. Do this whether you choose 5754 (H111) aluminium sheet and coil or other types.
In addition, ensure you don’t store your aluminium close to obvious water sources like pipes or steam vents. Keep everything at a good distance from open windows and doors too.
If you receive your aluminium in a cold state, let it get to room temperature gradually. It can take a few days, but will be worth it. Then you can breach or open your packaging.
If you discover moisture on your aluminium, you should let it dry thoroughly. Do this via evaporation by using dry air and fans if possible. By removing the moisture, you will stop the stains from appearing. At the same time, you will prevent the growth of existing ones. If it is possible, process your aluminium straight away and dry it while you are utilising it.
Come to us for help with 5754 (H111) aluminium sheet and coil
At Brindley Metals, we provide customers with the highest grade metals as well as a range of services to process them. This is something we can do for very competitive pricing too. Apart from our merchandise, and the help with processing we offer, we can provide you with all the knowledge you need.
So, if there’s anything you don’t understand about 5754 (H111) aluminium sheet and coil or any other metals we offer, just ask; we’d gladly advise you.