Xeralic: what it is, composition and application features

The substance known as Xeralic is a specific mixture, the main component of which is zinc chloride, dissolved in concentrated hydrochloric acid with the addition of ammonia. This chemistry provides powerful active flux properties designed to break down the oxide film on metal surfaces before soldering. It is the presence of aggressive acidic components that determines the scope of its use and dictates strict precautions during operation.

The process of interaction of the solution with the metal triggers a violent chemical reaction, during which the oxides are converted into soluble salts, freeing up a clean surface for soldering. Xeralic It is especially effective when working with difficult-to-solder materials, such as nichrome, stainless steel or galvanized iron, where conventional rosin fluxes are powerless. The high activity of the components allows soldering even on slightly dirty surfaces, although perfect cleaning is still recommended for maximum weld quality.

However, high efficiency comes at the price of increased corrosion activity of residual reaction products. If, after completion of the work, flux residues are not removed from the part, the process of metal deterioration can continue for years, leading to the appearance of rust and failure of the joint. Therefore, understanding that What is Xeralic? from a chemical point of view, it is critical for any craftsman who wants to avoid damage to products in the future.

Chemical composition and principle of action

The basis of the drug is an aqueous solution of hydrochloric acid, in which zinc reacts to form zinc chloride. To stabilize the process and improve wettability, add ammonium chloride, which decomposes when heated, releasing vapors that displace oxygen from the soldering zone. This combination creates an inert environment that prevents the metal from re-oxidizing when solder is applied. The mechanism of action is based on acid etching, where hydrogen ions actively attack oxide bonds.

Unlike neutral rosin-based fluxes, this composition is an electrolyte and conducts electric current until it completely dries and neutralizes. This places restrictions on its use in electronics, where there is a risk of short circuits or galvanic corrosion of traces. Usage ZnCl2 as a base it provides a high activation temperature, which allows you to work with refractory solders.

⚠️ Warning: The fumes released when the mixture is heated contain hydrogen chloride and zinc fumes, which are toxic and irritate the respiratory tract. Work should only be carried out in a well-ventilated area or under a hood.

Areas of application of flux

The substance is most widely used in electrical installation work involving the connection of large conductors and cables. It is often used for tinning conductors before twisting or soldering in sleeves, especially when it comes to copper or large-section aluminum wires. Unlike soldering microcircuits, the reliability of mechanical contact and deep penetration of solder between the wires are important here.

Builders and roofers use this flux to join galvanized steel elements, as it perfectly removes the oxide layer from the zinc coating. Without the use of active acid compounds, it is almost impossible to qualitatively solder galvanized steel, since rosin cannot penetrate the oxide layer. The composition is also relevant for repairing radiators, tanks and other containers made of ferrous metals.

• 🔧 Soldering large-section wires and cable lugs.
• 🏗️ Connection of galvanized steel roof elements.
• 🛠️ Restoration of cast iron and steel parts using brass.
• 🔌 Tinning of difficult-to-solder alloys such as nichrome.

Instructions for safe use

Before starting work, it is necessary to prepare the workplace by covering the surface with non-flammable and chemical-resistant material. Flux is applied with a brush or a special applicator directly to the area of ​​the future seam, avoiding contact with adjacent areas that are not subject to soldering. Excess solution can spread under the influence of temperature and damage insulation or adjacent parts, so it should be dosed carefully.

The heating process must be intense to quickly evaporate moisture and activate the chemical reaction. When using a soldering iron with a power of less than 60-100 W for large parts, prolonged boiling of the flux may occur, which deteriorates the quality of tinning. For massive structures, it is better to use gas burners or blowtorches, which provide rapid heating of the contact area.

After soldering is completed and the part has cooled, it is extremely important to remove any remaining active substance. To do this, the joint is washed with warm water using a brush, and then treated with a weak alkali solution (for example, soda) to neutralize the acid. Ignoring this stage will lead to the fact that after a few months a corrosion center will appear at the seam site.

Comparison with analogues and substitutes

Parameter Xeralic (Zinc Chloride) Soldering acid (HCl) Orthophosphoric acid Rosin Activity Very high High Medium Low Corrosivity High Very high Average Absent Application Ferrous metals, nichrome Steel, copper Stainless steel, non-ferrous metal Electronics, copper The need for washing Mandatory Mandatory Desirable Not mandatory

Pure hydrochloric acid acts faster, but it is more volatile and aggressive to human skin, and also loses its properties faster when stored in open containers. Phosphoric acid is often used as a gentler option for stainless steel, as it creates a protective film on the surface that slows corrosion, unlike chlorides.

Is it possible to replace Xeralic with an aspirin tablet?

Yes, in emergency cases, acetylsalicylic acid (aspirin) can be used to tinning wires. When heated, it melts and acts as an active flux, but has a specific odor and is less effective on highly oxidized surfaces compared to zinc-containing compounds.

Storage and shelf life

The product should be stored in tightly closed containers made of glass or chemical-resistant plastic, as acid fumes can damage metal lids and cases. The optimal storage temperature is from +5 to +25 degrees Celsius; freezing is not critical to the chemical properties, but after thawing the mixture must be thoroughly mixed. During long-term storage, precipitation of zinc salts may occur, which is not a defect and does not affect the performance characteristics after shaking.

The shelf life, provided the packaging is sealed, is practically unlimited, however, over time, volatile fractions may evaporate and the concentration may change. If the solution has become too thick or has crystallized at the bottom, a small amount of distilled water can be added to restore the working consistency.

⚠️ Attention: Store the container only in an upright position out of the reach of children. Accidental contact of contents with clothing leads to irreversible destruction of the fabric and the appearance of holes.

Frequently asked questions (FAQ)

Is it possible to use Xeralic for soldering microcircuits?

Strongly not recommended. Chloride residues cause rapid galvanic corrosion of thin traces and leads, leading to device failure. In addition, high flux activity can damage the varnish coating of the board.

What is the best way to wash off flux residues after soldering?

The best method is to rinse with hot water using a toothbrush, followed by a mild baking soda solution to neutralize the acid. After this, the part must be wiped dry and, if necessary, coated with a protective varnish.

Why does strong white smoke come out when soldering?

White smoke is the result of water evaporating and hydrogen chloride being released when the acid reacts with the metal and is heated. This is a normal process for active fluxes, but it requires mandatory ventilation of the room.

How to make an analogue of Xeralic at home?

Technically, it can be obtained by dissolving zinc in hydrochloric acid until gas evolution stops, but this is dangerous due to the risk of chemical burns and a hydrogen explosion. It is easier and safer to purchase a ready-made composition in a specialized store.