Aluminium Brazing And Uses Of Nocolok Flux In Various Industries

Brazing is the process of joining two or more metal items by melting a filler metal and filling it into a joint. The filler metal should have a low melting point than the metals that are to be joined together. The Nocolok flux is used widely as the fluxing agent for brazing aluminium items in automotive and many other industries. This fluxing agent is non-hygroscopic. It does not show any reaction when it comes in contact with aluminium at the brazing and room temperature.

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The Nocolok fluxing agent is soluble only 0.2% to 0.4% in water. It has non-corrosive properties. The shelf life of this fluxing agent is indefinite. It is effortless to use. You can use it by spraying, dipping, or flooding. Aluminium heat exchangers, like oiler coolers, radiators, heat sinks, and conditioning systems, are the products grazed with Nocolok. It is also used in flame brazing, induction brazing, and tunnel furnace brazing.

The Use Of Nocolok In Various Industries

The Nocolok filler agent is used in various industries, as follows:

  1. Automotive Industry

As mentioned above, many automotive industries use the Nocolok flux agent for the aluminium brazing process. This process is performed to produce aluminium heat exchangers, like heater cores, evaporators, air conditioning systems, and radiators. In the automotive industry, the Nocolok filler is used as the brazing alloy for joining two different aluminium components.

  1. Household Appliance Industry

Many household appliances, like pans, utensils, pots, etc., are made from aluminium and stainless steel. Therefore, the Nocolok fluxing agent and other filler metal powder are used for the aluminium brazing process. The aluminium base is joined with pots or pans with the brazing technique.

  1. Refrigeration

Another industry where the Nocolok fluxing agent is used is refrigeration. In the refrigeration industry, this flux is used for copper or aluminium flame brazing. Aluminium roll-band tubes are brazed with copper tubes.

  1. Electrical Appliance Industry

Electrical appliances are usually made up of aluminium and steel. In electrical appliance industries, aluminium tubes are joined to stainless steel or the normal steel using the flame brazing technique.

  1. Residential and Commercial Air-Condition Industry

It is observed that the use of air conditioners is increasing day by day in the commercial and residential sectors. For manufacturing brazed heat exchangers, Nocolok plays a vital role. There are several benefits offered by the brazed heat exchangers as given below:

  • Consumes less energy
  • Less weight
  • Reliable and optimum performance
  • Less noise and recyclable
  • Pressure drop reduction
  • Enhances heat exchangers’ heat transfer efficiency
  • Lowers down the temperature between the air-flow

7 Steps For Aluminum Brazing

Below is a brief guide for you about selecting and using the best flux, temperatures, materials, and filler alloys. All these parameters are used in the aluminium brazing process.

  1. Alloy

It is essential to choose the appropriate alloy in atmospheric conditions. Alloys not suitable for the brazing process are 2xxx, 5xxx, 7xxx, and 8xxx, except 7072.

  1. Clean Surfaces

For the flux to be spread evenly, metal surfaces should be clean. There should not be dust, dirt, oils, lubricants, or condensates present on metal surfaces. If metal surfaces are prepared incorrectly, the filler alloy will flow randomly, and the result will be an incomplete joint. Therefore, you must first clean metal surfaces using several techniques, like water-based, thermal, or chemical techniques.

  1. Remove Oxide Layer

Removing the oxide layer from metal surfaces results in successful aluminium bonding. Nocolok helps metals to remove their oxide layers and connects two aluminium metals successfully. Therefore, there is no extra step to be performed to remove the oxide layer from metal surfaces. Nocolok dissolves partially when it is in its molten stage and draws the oxide layer.

  1. Appropriate Flux And Filler Alloy

When Nocolok is used for the brazing process, an alloy of silicon and aluminium is used as a filler metal. This alloy is fusible. With the furnace brazing, an alloy of aluminium and 6.8 to 8.2% silicon is used. Also, the silicon percentage can range from 9 to 11.

  1. Select The Gap Size

Selecting the appropriate capillary gap size to fill the filler alloy and join two components is significant. If the gap chosen is right, the filler alloy in its molten state will spread evenly and fill the capillary gap.

  1. Sufficient Amount Of Flux

Generally, the loading for fluxing in the aluminium brazing process is 5 grams per metre square. This amount of flux gets distributed uniformly on the brazing surfaces.

  1. Heat Metal Components

Heating both metal components evenly in the brazing process is essential. All workpieces should attain an even temperature of 600 degrees Celsius. For a perfect joint and even temperature, you must adopt the slow heating process.


The Nocolok Flux is a sturdy fluxing agent used for joining two or more aluminium components tightly. It must be used in the correct quantity for workpieces to connect strongly.