Glue aluminum

Aluminum can be glued like any other metal. However, the special chemical properties of aluminum as well as the requirements for the glued component have to be considered. Below you will find out how to glue different pre-treated aluminum.

The chemical properties of aluminum

If aluminum is in the air, so comes in direct contact with oxygen, immediately begins the process of oxidation. This means that any untreated aluminum surface will very quickly have this oxide layer. This must be taken into account when gluing aluminum.

Suitable glue for aluminum

Different adhesives can be used for gluing aluminum:

PUR adhesive with silanized isocyanate primer
Epoxy resin adhesive
Adhesives based on methacrylate
MS polymers

Presets of the aluminum surface

In addition to the natural oxide layer, aluminum can be selectively oxidized. Anodizing is one such controlled oxide layer. So you have to distinguish between a natural and a controlled oxide layer.

Glue aluminum with natural oxide layer

Aluminum suitable adhesives can also be used on the natural oxide layer. However, since this oxidation layer is more porous and less stable, the force must not exceed 15 Newton per square millimeter.

If the force is greater, the oxide layer must be removed. In particular, in outdoor use is also to be considered that moisture can decompose the adhesive by weathering and thus weaken.

Aluminum with anodized layer (controlled oxidation layer)

The more anodized, the thicker it becomes. It concludes that adhesives stop correspondingly worse. Up to 5 μm, an anodized aluminum surface can still be glued well.

Especially aluminum parts, which are anodised from the outset for outdoor use, often have a layer thickness of 20 microns and more, since the weather conditions can no longer act as massive. However, the bondability is then massively limited.

Aluminum stick after removing the oxide layer

For home improvement, there are several ways to glue aluminum, if the oxide layer is to be removed. First, there would be the grinding. However, an oxide layer immediately forms again.

So you need to stick the aluminum immediately after sanding. If you want to be sure that there is no oxide, apply epoxy glue and sand the aluminum surface. Be careful not to remove the adhesive.

You can also stain the aluminum. In particular, the pickling with titanium zirconium is very well suited for epoxy resin adhesive, which should adhere well.

Extended or reinforced gluing of aluminum

Alternatively, if you want to glue them together, you can in particular screw together aluminum sheets at the same time. Another option is often used in model making. Inside is wood, outside each aluminum sheet. Instead of sticking the aluminum only to the wood, you can drill through the wood several times so that the glue can connect and harden through the wood.

Tips & Tricks

You can process aluminum in a variety of ways. If, instead of gluing, you want to try welding or soldering aluminum, you will find here appropriate guides.

Video Board: super glue & baking soda trick, how it bonds to aluminum