How to solder with citric acid

Acetylsalicylic acid soldering

All existing metals, as well as their alloys, can be combined with each other using two different technological processes. We are talking about welding and soldering. Welding of metals means short-term heating of two metal surfaces at the point of contact to extremely high temperatures.

At these temperatures, the surfaces to be joined undergo complete melting. As a result, a connection of two metals occurs at the level of interatomic bonds of the crystal lattice.

The consequence of this process is a monolithic welding seam, whose strength sometimes even exceeds the strength of the metal products being welded themselves.

What is soldering

Soldering is a completely different process. It does not affect the internal structure of the metal in any way. It occurs exclusively on the surface of the materials being soldered. No monolithic connections are formed at the atomic level during soldering.

To perform soldering, the presence of a third, lower-melting metal, which is called solder, is necessary. With the help of solder, the soldering process occurs directly. Pure tin or its various alloys are most often used as solder.

The task of any soldering is to melt the solder and ensure its good spreading over the surface of the metals being soldered.

As the solder hardens, it changes from its molten liquid state to a solid state and provides a reliable connection between two metal products.

In practice, everything turns out to be a little different. The fact is that all metals, without exception, have a fairly hard and chemically inert oxide film on their surface. The strength of this film varies among different metals. The most durable oxide film is formed on the surface of aluminum. This film, as well as all kinds of mechanical impurities that are always present on the surface of any metal, lead to the fact that the solder does not want to spread over the metal.

That is, in professional terms, tinning of the metal does not occur. Instead, the solder becomes a moving ball that rolls around the metal surface without connecting to it in any way. This suggests that the surface tension of the molten solder is much higher than the adhesion (sticking) of this solder to the metal surface. To enhance the adhesion of solder and ensure reliable soldering of two metals, so-called fluxes are used.

Acid fluxes

Why are fluxes used? The task of any flux is to:

• Dissolve the surface oxide film on the metal.
• Clean the surface from mechanical contamination.
• Prevent oxidation and the formation of a new oxide film.
• Reduce the surface tension of the molten solder, thereby facilitating its free flow over the metal.

Rosin

Among radio technicians, the most common flux is rosin. It is essentially pine tree resin from which the turpentine has been removed through an evaporation process.

It is widely used due to its low cost, ease of storage and chemical inertness. Rosin is used as a flux for soldering products made of copper, brass, silver, and nickel.

That is, those metals on the surface of which the oxide film is not very strong and is quite easily destroyed by the weak influence of molten rosin.

But when it comes to metals such as aluminum, cast iron, all kinds of steel alloys or iron, rosin stops working and its use in these cases turns out to be extremely ineffective. The rosin needs to be replaced and the flux made more aggressive to make the soldering process easier.

Soldering acid

chemically active acid fluxes were invented . There are several types of acid fluxes due to the fact that different metals form oxide compounds of different strengths on their surface.

The so-called soldering acid can be easily purchased at a specialized store and is inexpensive. But there is a small problem.

Most often, manufacturers do not indicate the exact composition of the chemical they sell under the name “soldering acid.” But, as you know, soldering different metals requires acid fluxes of different compositions.

Therefore, sometimes it will be much more rational to make one or another flux for a specific metal at home than to buy a pig in a poke.

Zinc chloride flux

For soldering, so-called pickling acid is used. This is one of the most common acid fluxes. This is the same soldering acid that is most often sold in specialized stores. This flux is mainly used for soldering iron. For example, pure hydrochloric acid can be used to solder roofing iron. Usually this is a solution of zinc in hydrochloric acid, in other words, zinc chloride.

All the necessary reagents for this reaction can be freely purchased at a chemical store, namely: granulated zinc and chemically pure hydrochloric acid. This is the composition of soldering acid.

The proportions are as follows:

• Concentrated HCl: 1000 ml.
• Pure zinc: 400 gr.

For mixing, you must have an appropriate glass, porcelain or ceramic container.

• The zinc is first placed in the container, and only then hydrochloric acid is slowly added to the zinc in a thin stream.
• In no case should you do the opposite and add zinc to hydrochloric acid. This can lead to very sad consequences, namely the splashing of acid in all directions.
• During the chemical reaction, hydrogen will be released. This gas, when combined with oxygen in the air, forms an extremely dangerous gas mixture called detonating gas. This gas explodes at any opportunity. Therefore, before you start dissolving zinc in hydrochloric acid, think about good ventilation. It would be ideal to carry out the reaction outside, in the fresh air.

Olein flux

The basis of this flux is oleic acid, which is found in olive oil or any fat. To prepare the flux, technical olein is used, which is mixed with lithium iodide.

It is used for soldering both pure aluminum and aluminum-based alloys. This is the only flux that can dissolve the extremely durable aluminum oxide film, while the protective flux layer remains until the end of the soldering process.

It is impossible to make oleic flux at home. Yes, this is not necessary. It is freely sold and inexpensive.

Orthophosphoric acid

The chemical formula is H3PO4. For soldering alloys based on chromium or nickel, flux is prepared in the following proportion:

• Ethyl alcohol: 62%;
• Phosphoric acid H3PO4: 32%;
• Rosin: 6%.

Sometimes the acid is mixed with zinc chloride in a 50/50 ratio to prepare a flux for soldering iron products.

The composition consisting of H3PO4 25% and diethylamine hydrochloride 75% is called active flux F-38N, which is used for soldering copper alloys, as well as medium-carbon and low-carbon steel. Solders pure copper well, as well as iron, steel and nickel-containing alloys.

Based on this acid, you can make any fluxes for soldering almost all types of metals, except aluminum, at home. The only problem is that acquiring pure acid is quite problematic.

Salicylic acid

Or the well-known aspirin. Purchased in tablet form at your nearest pharmacy. It costs a penny.

It belongs to the so-called inactive fluxes, that is, after soldering is completed, salicylic acid does not affect the contact point in any way and therefore no additional treatment is required after soldering to remove flux residues. Moreover, after hardening, salicylic flux protects the soldering area from corrosion.

You can solder with pure acid , using it in the form of a powder or a whole aspirin tablet. But it is much more effective to use aspirin as part of a multicomponent flux, which is called VTS.

VTS flux is used for soldering copper conductors, as well as products made of silver and platinum. The flux contains technical petroleum jelly as a filler, ethyl alcohol and acetylsalicylic acid.

This flux can be used to solder almost any metal, with the exception of aluminum.

The only disadvantage of aspirin: during soldering, extremely caustic smoke is released, which can damage the respiratory tract with frequent contact. Therefore, good exhaust is a prerequisite for productive work with this flux.

How to solder correctly

How to use soldering acid? The key to successful soldering is not only the correctly selected flux, but also the correct preparation for soldering. To do this you need to know the following:

• Before soldering, metal surfaces must be cleaned of rust and other contaminants using a file and sandpaper.
• All liquid fluxes are best applied to the surface using a special brush. In this case, maximum application accuracy and uniformity of distribution are achieved.
• The acid flux should cover the surfaces to be soldered with an even, uniform layer, without gaps. Otherwise, uniform distribution of solder over the metal surface will not be achieved.
• The tip of a well-heated soldering iron picks up a small amount of solder and transfers it to the metal surface pre-treated with flux. The solder is distributed in an even layer over the entire surface of the metal. This is called "tinning". The second metal surface is tinned in the same way. After this, both tinned surfaces are soldered.
• After completing the soldering process, it is necessary to remove any remaining acid solder. Otherwise, the acid will begin to destroy the metal and a corrosion center will arise, which can lead to destruction of the soldering area.
• Acid is neutralized by alkali. For the latter, it is best to use baking soda. The soldering area is sprinkled with soda and then washed with water.

Source: https://rem-serv.com/atsetilsalitsilovaya-kislota-payka/

Improvised means as flux for soldering

Fluxes are substances of organic or inorganic composition used in soldering metals. Their purpose is to reduce the surface tension forces of the molten solder and ensure better uniform spreading.

In addition, the flux protects the soldering surface from exposure to oxygen, and thereby prevents oxidation. In many cases, homemade flux can replace liquid or powder prepared in production. You just need to know what materials to use for it.

Main types

Fluxes are active (acidic) and passive (acid-free).

The former actively influence the top layer of metal during the soldering process, partially changing its chemical structure, the latter simply wash away oxides from the surface and create a thin film that prevents the access of oxygen.

After use, active fluxes must be washed off from the surfaces of brazed parts, as residual substances can cause corrosion. You can wash it off with water with a little added alkali.

Soldering acid, rosin, solder fat, and flux pastes are used as fluxes. The quality of soldering of various metals depends on the type of material and its characteristics.

After all, for each specific case, ideally, you need to select the most suitable composition.

The flux can be included in the solder paste or sealed into a hollow solder tube to improve soldering ease.

There are many ready-made soldering fluxes available in solid, liquid and gel form. If you urgently need to carry out soldering work, but there are no consumables at hand, you can prepare such a composition yourself, using improvised means.

Of course, a homemade, hastily prepared flux will be inferior in quality and characteristics to that produced in a factory, but it will be able to ensure high-quality soldering.

Aspirin and citric acid

To make flux, you can use any substances that have good solvent and antioxidant properties.

It can be:

• alcohols;
• acids;
• vegetable and animal oils.

The simplest flux is prepared by dissolving a tablet or powder of acetylsalicylic acid in water. Acetylsalicylic acid is in the medicine cabinet in almost every home (this is the most common cheap aspirin). It is necessary to dissolve the tablets or powder until the sediment disappears.

Citric acid powder (white granules) is also used.

There are tips to use lemon juice, but it is quite weak, so the effect of its use will be subtle.

When soldering with aspirin or lemon juice, a lot of gas is released, so the room in which they are worked must be equipped with an exhaust hood or well ventilated.

Alcohol, glycerin, rosin

You can get a good alcohol-rosin flux by dissolving rosin in ethyl alcohol. First you need to crush the rosin in a mortar as finely as possible.

Rosin dissolves very slowly in alcohol, and the speed of flux preparation will depend on its thorough grinding. After mixing the alcohol with rosin, it is better to leave the future flux for several hours to complete the dissolution.

You can speed up the process by placing the solution in a sealable glass container and heating it to 80 ℃ in a water bath. Alcohol rosin flux is completely neutral and does not even require rinsing after soldering.

Ethyl alcohol can be successfully replaced with glycerin. This glycerin flux will be thicker than alcohol rosin and will be more convenient to use. In this case, the dissolution of rosin will slow down.

It will be much more effective to first dissolve it in alcohol and then mix it with glycerin. In this case, the activity of the composition will significantly increase, but you will have to wash off the residue from the soldered workpieces.

It’s even possible to make rosin yourself, although it will take time. It is necessary to collect resin from pine trunks in warm, dry weather and melt it.

Can be used for soldering as a flux or its component, rosin for bowed string instruments. It is of very high quality and well cleaned. But its price is much higher than that of soldering rosin.

Hydrochloric and phosphoric acid

A very effective flux is obtained by dissolving zinc granules in hydrochloric acid. To do this, concentrated acid must be diluted in equal parts with water and the granules placed in a glass container should be poured with this solution. For complete dissolution, zinc will be required at the rate of 412 g per 1 liter of hydrochloric acid.

The dissolution process will be accompanied by a rapid release of hydrogen from the acid, so it is better to prepare in rooms with very good ventilation and away from open fire.

Using flux obtained from hydrochloric acid, steel workpieces are successfully soldered. If you add ammonia to the solution (the same amount as zinc), then this composition can be used when soldering absolutely any metals and alloys.

A good flux is phosphoric acid. It is used when soldering nichrome and stainless steel.

Liquid fluxes are best applied with a thin brush, and should be stored in a tightly sealed glass container with a narrow neck.

Application of fat

Soldering flux can be made from fat with a fairly high melting point. Then at room temperature it will not soften on its own, which will make it easier to work with.

To obtain such a flux, the fat must be melted and mixed with crushed rosin and ammonia in a certain proportion. For three parts of fat by volume you will need the same amount of ammonia and one part of rosin.

For ease of use, the finished flux can be placed in the body of a medical disposable syringe and, if necessary, squeeze out the required amount.

If you are not sure whether a homemade flux is suitable for soldering a part, then you can do a little research. It is necessary to distribute the prepared substance over the surface of a piece of the same metal that is to be soldered.

If, when heated, the flux is evenly distributed over the surface, then it is considered suitable for soldering. If it collects in balls and flows down, then it will be able to provide satisfactory wettability of the part.

The ability to dissolve the oxide film on the metal surface is checked by washing off the applied flux. If the surface remains clean after washing, then the flux dissolves oxides well. On the contrary, if traces of an oxide film or rust remain, then soldering with this flux cannot be performed.

Source: https://svaring.com/soldering/flus/izgotovlenie-svoimi-rukami

DIY soldering acid: composition and purpose, DIY production

Every person who has had to work with radio electronics has repeatedly used a soldering iron to solve their problems, so he knows what the operating principle of such equipment is. But due to the unpleasant odor emitted when processing a structure using classic solder, as well as significant difficulties at different stages of operation, this technology is not in great demand and has a number of simpler analogues.

To make the upcoming soldering more productive, many welders use special substances - fluxes, with the help of which the solder spreads evenly over the soldering site. Among the main fluxes, rosin and soldering acid are distinguished. The first option is indispensable when soldering copper and silver, and acid is used in particularly difficult cases. How soldering acid works, the composition and other features of such a substance are the main questions that concern many inexperienced beginners.

If we highlight the main recommendations for successful soldering with acid, they will look like this:

1. When choosing a suitable solution, you need to understand the type of metal or alloy. When soldering iron, including galvanized iron, a unique type of soldering acid is used, represented by a solution of zinc chlorate. Soldering of stainless steel is carried out using phosphoric acid for soldering, as well as multi-component fluxes. A material such as aluminum cannot be soldered , which is due to the lack of suitable fluxes capable of dissolving the oxide film of the material. Acid cannot be used for soldering printed circuit boards, as this increases the risk of the formation of corrosive elements and short circuits between conductors.
2. If you intend to use soldering acid for your own purposes, you can purchase it in the form of a paste at the appropriate store. Nevertheless, many welders make their own soldering acid, claiming that such an action does not require any special difficulties. You need to take about 100 ml of hydrochloric acid, put pieces of zinc in it, for example, removed from batteries, and wait for the chemical reaction to complete, during which hydrogen will be released. Given this feature, it is better to conduct the event in a ventilated environment away from sources of fire. If the hydrogen bubbles stop rising, let the solution sit until clear, and then carefully pour it into the bottle. That's it, the highly effective soldering acid is ready.

Instructions for use

1. Immediately before soldering, it is necessary to clean the surface with a file or sandpaper, which will avoid all kinds of contamination.
2. Acid should be applied to the adhesion site, for which you can use a brush. Next, you need to cover the structure to be soldered with solder based on tin or its alloy.

   If the substance does not apply evenly, you will have to repeat the acid treatment again.

3. At the next stage solder carefully surfaces. When working with a heated soldering iron, do not forget about safety rules and try not to clutter the work area with materials that ignite very quickly.

4. After completing the procedure, the acid should be neutralized using an alkali, for example, a soda solution, and then rinse the adhesion site to get rid of any remaining acid. In rare cases, acetylsalicylic acid plays the role of a flux, although its use requires a more complex approach.

If you have ever worked with a soldering iron, then you know that soldering is a unique type of permanent connection of metal products using low-melting metal. The technology itself is selected taking into account the type of metals that are to be soldered, as well as the environmental conditions where the action will be performed.

For example, processing printed circuit boards from some electronics and repairing silver jewelry are significantly different from each other.

When soldering this way, you should use a soldering iron, solder, and also a flux, which is colophonium.

The step-by-step instructions look like this:

1. It is no secret that for soldering elements with a high silver content, solder is used, which contains about 60% tin and 40% lead, which can melt at a temperature of 180 degrees Celsius. Try to prepare solder, which will be indispensable for soldering electronic circuits. This product consists of thin tubes that are filled with resin and act as a flux.
2. The surface that will be solderable must first be cleaned of any defects and irregularities that may appear when exposed to the oxide film. In this case, the heated solder can create an effective connection with the silver.
3. The part in the soldering zone is heated to such temperatures that natural melting of the solder begins. However, at this stage, some difficulties cannot be avoided, which may be associated with insufficient power reserve of the soldering iron for sufficiently high-quality heating. When soldering silver products, it is important to protect the area from possible exposure to atmospheric oxygen. In this case, colophonium is used, which can create a protective film over the soldering area.
4. As for soldering jewelry, it is carried out using high-temperature solders that correspond to the metal standard, or using solders of a lower standard, but containing silver. Soldering jewelry with tin is necessary only in the most extreme cases, and only after prior agreement on all details with the owner of the ring, chain, bracelet or other item. If you do not know how to perform such an action correctly, this can cause damage to an expensive structure.

Boards

It's no secret that soldering radio components into boards is a simple process . It is much easier to do than connecting loose wires, since the holes in the boards are intended to fix the soldered parts.

However, you need to understand that the final result is directly related to the experience and responsibility of the worker. The first circuit that is assembled on a breadboard cannot be called very successful.

But don’t worry - after some time the quality of the connections will increase significantly.

Step-by-step instructions and features of such soldering consist of the following points:

1. The main goal of the upcoming work is to effectively connect the chip to the board so that a uniformly good soldering is obtained. The event can be divided into several separate stages.
2. First, you need to simultaneously bring the solder and the tip of an already heated tool to the area where the connection is required. It is important to follow the key rule, making sure that the soldering iron tip is in full contact with the pin being processed and the board itself.
3. During processing, you cannot change the position of the soldering iron tip until the entire contact area is covered with an even layer of solder. In most cases, this takes from 0.5 to 1 second. This time period ensures sufficient heating of the soldering area.
4. At the next stage, you need to circle the tip of the tool near the contact being processed in a semicircle, moving the solder in the opposite direction. In the same way, apply another millimeter of solder to the soldering area. During this period, the selected area will warm up quite well, so the solder melted under the influence of surface tension will be distributed evenly over the contact area.
5. After successfully applying the required amount of solder to the selected location, you can move the wire away from the soldered area.
6. And at the last stage, you should quickly remove the tip to the side. In a short period of time, the liquid substance, with a small layer of flux, will take its final shape and harden, creating a strong connection.

It is important to understand that if the sting is sufficiently warmed up, the action will not take more than 1 second. Try to hone your skills and follow the recommendations of professionals. This way you can achieve incredible success.

Copper

Every man can learn to solder, because this procedure does not require any special skills or secrets. In any case, the ability to solder can be very useful and useful in everyday life, where you need to connect wires and parts of electrical circuits, repair a car radiator, and also install copper pipeline elements.

It's no secret that copper is one of those materials that lends itself very well to soldering.

In addition, the surface of products made of this metal can be easily cleaned from oxide film, dirt, unevenness and other defects without the use of expensive chemicals and aggressive agents.

Most fusible metals have excellent adhesion to copper and do not require the use of expensive or complex fluxes. Copper practically does not interact with air when heated.

Due to such unique properties , metal can be soldered in a wide variety of environmental conditions, using various types of fluxes and solders.

To solder parts, you should use electric soldering irons or soldering stations with different power. It is known that the greater the mass and volume of the part, the higher the power indicators of the working tool should be. If you've never soldered before, a 25-50W device might be your best bet

Other soldering features

At the learning stage, many beginners have a question: “what is solder and flux.” Solder is a common form of low-melting metal that is required for successful soldering of radio circuits, electronic components, and jewelry.

Most often, solder is made from tin, but in its pure form such metal is not cheap, so it is used only for tin-plating and soldering of utensils, which are used for storing and preparing food.

If it is necessary to solder wires and electrical circuits, the tin-lead solder option is used.

When performing soldering work, you may need the following tools and accessories:

• stand for soldering device;
• side cutters;
• pliers;
• tweezers;
• stationery knife;
• vice;
• desoldering pump or copper braid.

The soldering process itself includes several steps:

1. Cleaning the selected area to a shine.
2. Dipping the soldering iron tip into rosin for more effective cleaning.
3. Firmly pressing the connected elements together.
4. Then it requires applying a soldering iron with a small amount of solder at the end to the junction of such parts.
5. Next, you need to run the soldering iron tip along the part or wire, doing this as quickly as possible to avoid burning out the rosin on the tip.
6. The soldering area should be thoroughly heated so that the rosin, when melted, covers the entire surface of the part, and the solder fills the gap between the parts.
7. Be sure to remove excess solder with a soldering iron or desoldering iron. It also wouldn't hurt to use braid.

If all operations are carried out exactly according to the established rules, the hardness of the solder will become maximum, and its distribution will be uniform.

If during the solder solidification stage the soldered parts move from place, most likely the soldering is not good enough. To avoid such a course of events, it is enough to learn how to avoid making many mistakes.

Considering the above information, we can confidently say that if you wish and have the appropriate guidance, you can comprehend all the secrets of soldering in a few hours and experiments. The main thing is not to give up when faced with mistakes and troubles.

At home, you can learn to solder in a variety of ways, which will allow you to achieve the highest quality fastening of parts and the tightness of containers.

Today, using soldering acid, you can successfully join almost all types of metals and alloys, electrical wires, car radiator housings, metal utensils and many other everyday items.

Source: https://tokar.guru/instrumenty/payalniki/dlya-chego-nuzhna-payalnaya-kislota.html

How to use soldering acid when soldering products

Soldering acid (also called etching acid) is used in the preparation or repair of various metal objects or devices, when some parts or small parts need to be connected to each other very firmly.

Not everyone knows what soldering acid is, why it is needed, where you can get it and the principles of working with it.

Features of metal soldering

In order to understand the full range of “possibilities”, you need to know the difference between two methods of joining metals: welding and soldering.

Welding is the process of heating metals to their melting point and then joining them to each other through interatomic molecular bonds.

Soldering is a completely different process of joining metals, in which two bodies, relatively speaking, made of different “types” of metal, are connected to each other by laying another material, naturally molten, whose melting point is much lower.

The main thing in this matter is to provide this “lubricant” to the surfaces of both parts that need to be connected.

Necessary procedures before work

Before soldering, as before any other work, it is necessary to perform a number of procedures that contribute to a better result of the work:

1. Before joining metals to each other, they must be cleaned of dirt and oxide film that prevents the substance (hereinafter referred to as “solder”) from spreading over the surface. This condition must be observed, otherwise the solder, like a ball, will concentrate in one place and will not spread.
2. For the most successful spreading of solder over the material, it must be treated with a flux solution, which will protect the metal from corrosion and oxidation. The most common flux is rosin. This "household" flux (more often used for household work than for industrial purposes) is used for alloys of the common metals: copper, brass and aluminum. In the case of iron, cast iron and steel, so-called pickling acid is used for soldering.

Source: https://pochini.guru/sovety-mastera/kak-polzovatsya-payalnoy-kislotoy

Types and uses of soldering acid

[Acid for soldering is necessary] if the use of rosin does not allow the necessary elements to be properly soldered together.

The use of soldering acid for soldering helps remove the oxide film layer from the surfaces being soldered and makes it possible to properly prepare them for joining.

As a rule, rosin is used to prepare copper parts for soldering with your own hands. But soldering acid is used for tinning not only copper, but also its alloys - bronze and brass.

And also for stainless steel, precious and ferrous metals, aluminum and nickel, even for soldering cast iron.

The need to use acid fluxes

Any soldering acid - hydrochloric or phosphoric acid - is designed to create an ideal environment for the interaction of solder with elements.

Their use makes it possible to remove contaminants and oxides from the working area, prevent the resumption of the oxidation process and reduce the tension of the solder, in order for it to spread more freely.

As a result, reliable soldering of parts is ensured.

Depending on the type of metal, the flux for soldering is selected. It is worth noting here that soldering acid is not used when assembling boards.

Acid belongs to the category of aggressive media and contributes to the destruction of components standing in its path.

In addition, it is an ideal electrical conductor and has the property of creating additional conductive channels.

Therefore, you should not even count on neutralizing the acidic environment after soldering.

DIY hydrochloric acid flux

Often, to process the parts being soldered, a flux is purchased, which is commercially available and is simply called soldering acid.

The manufacturer supplements the product with instructions on the conditions of its use, which makes it easy to navigate its purpose.

IMPORTANT TO KNOW: Why use rosin for soldering?

Usually this is tinning and soldering of stainless steel, silver, copper, aluminum and various alloys.

In the production of flux, hydrochloric acid is used, in which zinc is dissolved, resulting in a base - a zinc chloride compound. It is quite easy to make such a composition at home with your own hands.

To prepare the composition you need to take:

• 1 liter of HCL (concentrated hydrochloric acid);
• 412 g Zn (zinc).

Next you will need a container made of glass, ceramic or porcelain. First, zinc is placed in the dishes, then hydrochloric acid is poured.

It is very important to prepare the composition with care; fill ¾ of the container with acid.

Zinc and hydrochloric acid can be bought in special chemical stores, but if you have old AA batteries at home, Zn can be easily obtained from them.

After the reaction of dissolving zinc in hydrochloric acid occurs, the evolution of hydrogen will stop.

That is, bubbles will no longer form in the liquid, it will become transparent. The prepared soldering acid composition is carefully poured into a tightly sealed glass container.

Precautionary measures: when making flux, it is recommended to be near running water; if the composition suddenly gets on the skin or, even worse, in the eyes, it is necessary to rinse them with plenty of water.

By the way, hydrochloric acid in its pure form can be used as a flux, provided that iron parts are processed.

Phosphoric acid for flux production

The second common type of soldering acid is phosphoric acid - H3PO4. It also ideally removes oxide film from metal surfaces and prevents its renewal.

Reference: H3PO4 (orthophosphoric acid) is a component of many anti-corrosion compounds for metal processing.

To carry out high-quality soldering of elements made of nickel or chromium, such acid is used undiluted. Moreover, the composition prepared using it includes 1/3 of ethanol or ethyl alcohol.

IMPORTANT TO KNOW: Typical welding defects and types of defects

The share of orthophosphoric acid is 32%, and 6% is rosin.

In other acid compositions used for tinning and soldering, the proportion of acid can reach 100%.

Very often, H3PO4 is combined with zinc chloride, and its mass in the finished flux can reach 50%.

The use of phosphoric acid is not limited to soldering nickel alloys; it is used to connect elements made of stainless steel, copper, aluminum and low-alloy steel.

Orthophosphoric acid is a component of the classic active flux "F-38 N", the use of which makes it possible to solder copper alloys and pure copper, various steels and chromium-nickel alloys.

“F-38 N” is an excellent option for carrying out the work process in hard-to-reach places; it has the ability to protect welded elements from corrosion.

The components of “F-38 N” are: diethylamine hydrochloride and 25% phosphoric acid.

Orthophosphorus soldering composition is characterized as fire and explosion-proof. It is recommended to store and use the product with all precautions.

In case of contact with skin, rinse for at least 10 minutes under running water.

Use of tin for soldering

Different materials can be used for soldering metals, but connecting elements with tin is much easier and more convenient.

Tin can be used to connect parts made of stainless steel, aluminum, copper, and its alloys.

Tin is melted at a temperature of 2500; for this purpose, various heating devices can be used:

A soldering iron is a device with a metal working part and a plastic handle, and can have a variety of tips.

Heats up with a gas burner.

Electric soldering iron - the set includes replaceable tips of various sizes and shapes. The structure is assembled from a soldering rod and a heating coil, which can have different heating power.

IMPORTANT TO KNOW: Laser metal welding technology

Gas burner - a portable design is a container with a handle and a nozzle for creating a fire of varying intensity.

How to properly solder tin on stainless steel?

For soldering stainless steel elements, it is recommended to use active soldering acid, for example, zinc chloride or phosphoric acid.

Flux is applied to the surface of the stainless steel right before soldering begins. The tip of the soldering iron is tinned with molten tin and the surface of the stainless steel begins to warm up well.

The procedure is repeated until the coating becomes uniform. During the soldering process, you can use rosin, which will make the surface smooth by removing oxide from the solder.

After soldering the stainless steel is completed, the product is washed from acid residues with soapy water. Excess rosin is easily removed in cold water.

It is worth noting here that high-quality soldering will have a uniform and smooth surface.

How to properly solder aluminum with tin?

Before soldering aluminum, the surface is cleaned using emery cloth, then the work area is degreased with an organic solvent.

To solder aluminum you will need a soldering iron with a power of 100 W, as well as solder made of tin - 95% and bismuth - 5%. Stearic acid can be used as a flux.

Since aluminum products are difficult to solder due to the rapid formation of an oxide layer after stripping, it is necessary to fill the surface to be joined with hot rosin.

Then, use a soldering iron tip to take the solder and transfer it to the working part treated with rosin.

After tinning the aluminum in this way, it will become easier to solder the surface; if necessary, even copper wires can be soldered to it.

Source: https://rezhemmetall.ru/kislota-dlya-pajki.html

Soldering acid recipes - Welding Pros

Soldering acid is a flux that can be classified as a separate category, because it has an aggressive effect on materials that are needed during work.

This flux mainly spreads in a liquid state, and this does not depend on its concentration. Sometimes you can purchase a concentrated substance and then dilute it, or perhaps buy a ready-made, diluted one.

In addition, everyone can easily make soldering acid on their own.

The properties of materials must be selected according to those factors that are necessary for their use.

Soldering acid is intended for those metals that are heavily contaminated, because oxidation occurs on them, and a large amount of rust remains on the surface.

The material is very active, so it is necessary to work with it carefully and avoid contact with human skin and mucous membranes. You must first carefully familiarize yourself with the rules and methods of using acid, and only then begin to use it for its intended purpose.

In the process of producing soldering acid yourself, it is necessary to use special technology. In the end, the result should be a material that will have the properties prescribed by GOST. This is what will make the flux high-quality and reliable so that the connections are strong.

It is necessary to ensure that the properties and functions of the acid work even after soldering the metals, because the material removes films and rust from the surface, and also prevents their reappearance.

You should also take into account the spreadability of the materials being soldered over the surface and the adhesion to metals and products.

Characteristics, composition and properties

It is necessary to know exactly what the material should consist of, and only then begin its production. Soldering acid includes:

• wetting additive;
• ammonium chloride;
• deionized water;
• zinc chloride;
• hydrochloric acid.

Soldering acid, created independently, may consist of other components. You just need to do everything to ensure that the flux has all the necessary properties. It is necessary to ensure high activity of this material.

It must interact with the necessary materials in a minimum amount of time, and also destroy all substances that prevent normal soldering. However, it is worth considering that small parts may be damaged and deteriorated when exposed to acid.

Solder active fat has the same properties.

The acid has a rather unpleasant odor, so when a person inhales it, his health may suffer. That is why it is recommended to use a respirator when working with this material.

Well, the work area must be constantly ventilated.

It is necessary to protect your hands, skin and mucous membranes from acid; it is necessary that the workpiece gets only into the places necessary for soldering.

Materials and tools for making acid

You need to know that the soldering acid you make yourself will have a slightly different composition than the purchased one. However, it will be simpler. To prepare such acid, you need to use some equipment:

• Glass container or jar for mixing and preparing the material.
• Zinc granules or cups from used batteries containing this element.
• Tap clean water.
• Concentrated hydrochloric acid, which is capable of dissolving unnecessary impurities and substances.

Making acid yourself

First you need to take a container or jar for mixing the acid. This is where the zinc or batteries and their remains are placed.

Only after all of the above can hydrochloric acid be poured into the container. The main thing is to act with great caution, because if it comes into contact with the skin, you can get a serious burn.

The acid in the container should not be more than 3/4 of the volume of the entire composition.

As a result, it turns out that the proportions should be like this. For 1 liter of hydrochloric acid, 412 grams of zinc are needed, but this can only be measured using special tools. Therefore, it is worth knowing that there will be some deviations in one direction or another.

The liquid gradually becomes clearer and cleaner. When all processes are completed, it is necessary to pour the liquid into a tightly closed container. All these materials can be easily purchased in stores specializing in the sale of chemicals and reagents. When using batteries, you can see that almost any of them will do.

If you need to make a material with weaker properties, then you should slightly reduce the aggressiveness. In this case, it is recommended to add a little water to make the solution more liquid and with weaker properties.

However, you need to be careful, because the liquid can splash and get on the skin and mucous membranes of a person.

In this case, you should choose the proportions yourself, adhering to the specifics of the required soldering.

Making soldering acid yourself

First, you should take care of your own safety, because using acid is very dangerous and can cause irreparable harm to your health. If acid production is carried out in enterprises and industrial areas, then everything must be done in special-purpose cabinets.

The reagents are reliably protected from outsiders, and they are poured strictly under special hoods. At home, it is recommended to use protection, gloves, goggles, respirators and other devices. Dissolving the acid should only be done in a well-ventilated area or even outside.

Indeed, in the process of creating acid for soldering, hydrogen is constantly released into the air in large quantities. It is also necessary to take care, just in case, of water, with which you can quickly rinse the area of ​​skin on which the substance has come into contact.

It is best to use cold tap water because in the event of an accident, it will reduce pain and quickly clean the wound.

If this substance is spilled on the surface, it is best to wash it off with a special mixture of water and alkali.

You must also remember that this material must be stored correctly, the container must be closed and sealed, storage is carried out in a dark and cool place.

It is recommended to prevent unauthorized people from accessing the soldering acid to avoid danger to others. Flux is sometimes made from pure hydrochloric acid without zinc and water. However, it is mostly used only for iron products.

Source: https://fgpip.ru/drugoe/retsepty-payalnoj-kisloty.html

DIY liquid flux for soldering

Fluxes are substances of organic or inorganic composition used in soldering metals.

Their purpose is to reduce the surface tension forces of the molten solder and ensure better uniform spreading.

In addition, the flux protects the soldering surface from exposure to oxygen, and thereby prevents oxidation.

In many cases, homemade flux can replace liquid or powder prepared in production.

You just need to know what materials to use for it.

How to replace soldering acid at home?

Soldering acid is one of the most popular types of fluxes when it comes to using it in complex work, that is, when soldering metals that are difficult to process.

It is characterized by a high degree of aggressiveness, due to which it does an excellent job of removing fatty films, oxides and other types of contaminants from the surface before soldering.

In addition, the acid ensures the formation of a protective film that prevents the negative effects of environmental factors on the metal.

However, when working with simple connections, especially in cases where thin metal elements are used, it is better to avoid using soldering acid. The danger is that it can simply corrode the metal, so sometimes it is better to look for another flux option.

It is extremely important to pay attention to the concentration of soldering acid, since it can be sold in concentrated and diluted forms. For each specific case there must be a solution of suitable strength so that there are no negative consequences.

The use of excessively concentrated acid for soldering is strictly prohibited. If you do not have a solution of the required concentration on hand, you should take care to bring it to the required parameters, or use another substance that has similar properties.

Advantages of soldering acid

• Excellent for use on hard-to-solder metals.
• It has a fairly low price, and in addition, you can prepare it yourself.
• It copes well with removing plaque and oxides, while simultaneously preventing their further formation.

Negative points

• Due to the excessively aggressive environment, it is impossible to work with thin parts.
• Direct contact with human skin can lead to extremely serious consequences, since the acid can corrode not only the skin, but also muscle tissue.
• The acid has an extremely unpleasant odor, and the vapors released when using the substance are extremely harmful to the respiratory system.

What can soldering acid be replaced with?

There are not many substances that can be considered as an alternative to this acid. Some of them can be prepared at home without any problems, although it is not always possible to obtain the desired properties.

One of the simplest and most accessible substances that can be used instead of soldering acid is an aqueous solution of ordinary aspirin.

To obtain it, you just need to take a tablet, crush it to dissolve faster, pour it into a container of water and mix thoroughly until not a single solid particle remains.

The use of the resulting solution is similar to other types of flux. The undoubted advantage of such a substance is its absolute harmlessness and safety.

You can also use citric or acetic acid, but they are not as effective as soldering acid. They are sold already in diluted form, so no additional manipulations with them are required.

Another option is concentrated hydrochloric acid. It is one of the main components of the original flux, but can also be used to make soldering acid at home. Due to its high aggressiveness, it allows you to efficiently get rid of a wide variety of types of contaminants and guarantees reliable protection. However, it is hazardous to health and can corrode thin elements, so these aspects should be taken into account when soldering.

Active solder grease has proven itself well, and copes well with contaminants. Also, its undoubted advantage is ease of use and ease of placement on the surface of the product. However, like soldering acid, it is a highly aggressive substance that poses a danger to human health and is not recommended for use with thin metal products.

A worthy alternative to soldering acid is phosphoric acid. It is easy to use, affordable, copes well with oxide, grease and other films and deposits, but is gentle on metals.

If you don’t have the original soldering acid on hand, you can prepare a replacement for it at home. Of course, it will not have such a rich cast, but it will still cope well with the tasks assigned to it.

Conclusion

Instead of traditional soldering acid, you can use a lot of other substances that have different properties, but are similar in their effect.

Some of them should be used with caution, keeping in mind their high aggressiveness, while others are absolutely safe, both for metal and for humans.

For each specific case, you can select the most suitable analogue in terms of its properties, which will allow you to painlessly endure the absence of soldering acid.
For many types of fusion welding, a special welding wire is used, which differs in size, diameter and properties

Source: https://svarkagid.com/chem-zamenit-payalnuyu-kislotu-v-domashnix-usloviyax/

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Soldering is one of the most important technological processes in radio electronics. As our manager said: reliable soldering is the key to success. But without a good flux, high-quality soldering is impossible. Many people have been soldering successfully for a long time, but not many are well versed in this issue. We'll talk about the types and uses of fluxes here.

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WATCH THE VIDEO ON THE TOPIC: Vaseline + citric acid = flux + rosin

3 household tricks that will make your life easier

Super flux from the grocery store. Is the wire not getting tinned? I would say that quite often you come across wires and parts that are practically not tinned with ordinary rosin, even in an alcohol solution. And the point here is not the oxide film that formed during long-term storage, but rather the specific coating of the part or wire.

https://www.youtube.com/watch?v=DboW0xHdrQw

Ordinary copper wires, pinkish in appearance, can be tinned without problems, even after long-term storage. Go back 1 2 3 4 5.

Check the box:. An ordinary aspirin tablet will help you - a method that is quite widely known!

Aspirin vapor can cause suffocation. The advantage is that it does not crumble, so there is no need to catch crystals with a wire, just put a wire and ludi on the tablet. Thanks for the advice.

My friend, in Soviet amateur radio equipment, nichrome wires are perfectly soldered with lemon, for example for New Year's igniters of pyrotechnics with remote start, and for soldering wires, an aspirin tablet is perfect, the varnish flies off with a bang, ammonia works great for removing oxides from copper, acid works for stainless steel, but be careful with it - with it over time it eats up the metal into salt, but this concerns copper and doesn’t matter to stainless steel.

Liquid for electronic cigarettes works very well, or rather glycerin and propylene glycol, which are in its composition. Regular cheap aspirin, excellent flux, even without stripping! A very old method is tinning on an aspirin tablet. In any case, an exhaust hood is advisable - the vapors are harmful to breathing.

This is the case if you work 25 hours a day. A piece of rosin or rosin in a jar becomes dirty over time, slagging, in short - not comme il faut. And if you apply it to a circuit board or to some part that doesn’t fit in the jar, turn off the light altogether! Aqueous solution of rosin!!! For contacts, wires, etc. An option is a solution of rosin in alcohol. Plus - the heat of boiling off of the solvent is lower, minus - it dries very quickly in air and is more flammable.

Guests September 25 Does rosin dissolve in water?! Yes, you should be given a Nobel Prize! Hi all! Good advice about “citric acid” – great! It’s as easy to use as rosin, you apply the wire to the tablet and solder it, soldering iron. The smell, however, is specific. It is very convenient to tin with a slightly overheated soldering iron, on a piece of ordinary vinyl chloride insulation from electrical wires or the same “cambric”.

The same applies to winding wires. They are tinned without removing the enamel. I read about another method in the old Radio magazine. Instead of aspirin, take a hydropyrite tablet, dry hydrogen peroxide, which is also used to lighten hair.

An interesting option with citric acid, upon request, I can add that aluminum can be successfully soldered using an aspirin tablet instead of flux. An acid flux from an aspirin tablet would be better. We put the wire on the tablet and tin. Everything is tinned and soldered using phosphoric acid, which, if you solder often, should simply be available at home.

I tried it - you have to not breathe for 5 minutes - it’s terrible. The fumes are very, very harmful. You can also use an aspirin tablet. This is also an acid. You can also use acetylsolicylic acid tablets. I was friends with one grandfather, a graduate of the first classes of vocational schools. They were taught many tricks. Once he suggested that instead of soldering acid, you can rub the place that needs to be tinned with ordinary garlic with a fresh cut.

I tried it, it works quite well. In every house, the neighbors have a banal aspirin. Everything is great. I didn't know about lemon. Liquid flux can be obtained from rosin with alcohol. Good evening. So it had a lot of useful tips about soldering, I remembered one and still use it, especially when I need to solder steel products.

This is ordinary aspirin, now called acetylsalicylic acid, it works amazingly, the only inconvenience is accidentally sniffing its smoke, it’s not fatal, but it really tickles the nose.

People, don’t you read what’s written? Why clutter up the topic? I tried tinning wires with some kind of coating similar to zinc. In 5 minutes of labor I almost died, but I tinked. Thanks for the lemon and garlic, I’ll try it! Hydroperite in tablet. It doesn’t smell like aspirin, only water is released, the effect is the same. Login to the site Don't remember me. Forgot your password?

Improvised means as flux for soldering

Author: Kulibin Alexander Davydov. Hello today, we would like to present you with a list of soldering chemicals for your reference. Brief introduction. Soldering is one of the most important technological processes in radio electronics. Soldering is used to obtain a permanent connection of parts made of different materials by introducing between these parts molten solder material, which has a lower melting point than the material of the parts being connected.

How to make a simple flux for soldering with citric acid with your own hands.

How to make your own soldering flux

Related News How to make flux gel quickly and easily. Several industrial fluxes Which flux should I choose for soldering? Review of fluxes from my workshop. Super flux from the grocery store. Soldering accessories from China!!! How to make flux gel Rosin with your own hands for free Soldering aluminum is an unusual way! Handmade Powerful Heat Gun.

Flux for low temperature soldering

Fluxes are substances of organic or inorganic composition used in soldering metals. Their purpose is to reduce the surface tension forces of the molten solder and ensure better uniform spreading. In addition, the flux protects the soldering surface from exposure to oxygen, and thereby prevents oxidation. In many cases, homemade flux can replace liquid or powder prepared in production.

Authors: Silaeva, Voylenko, Oleshko.

How to replace acid when soldering with a soldering iron?

After soldering, a layer similar to craquelure is formed on the copper product, very hard, but in some places it breaks off. I think it's called scale, sorry if it's not. Lemon does not help, only the black layer from the burning flux is cleaned off. What should we do about this? The product in the photo is incompatible with life, there is a very serious defect.

Do-it-yourself liquid FLUX (FIM) from citric acid!!!

All the best! This rating contains the best fluxes for soldering and is compiled from personal preferences and reviews of electronics repair specialists. Master Soldering has started to write at least something about soldering! I admit, I repent, I will correct the situation.

I plan to publish reviews of soldering processes, soldering tools, soldering videos and new technologies in the world of soldering. And today I will give my rating of the 10 best fluxes for soldering.

This rating was compiled based on personal preferences and all sorts of reviews from familiar electronics repair technicians of various levels and does not pretend to be exclusive. Let's go - soldering fluxes.

The flux contains components in the following ratio, wt.%: citric acid; triethanolamine; ethyl alcohol the rest.

Fluxes and solders or rosin must die

I have already encountered rosin problems, when even a normally washed board begins to fail, and measurements show that the resistance between the tracks is measured in tens of kiloohms. The board has already been washed with both hot water and isopropyl alcohol with a brush. After another very long wash with a propyl brush and then more hot water, the glitches went away.

Dear readers! Our articles talk about typical ways to solve everyday problems, but each case is unique. If you want to find out how to solve your particular problem, please use the link below. It's fast and free! View full version: how to solder without rosin. Speccy is our choice!

I love soldering SMD chips, and I have a question about how to properly clean the board from flux. They also suggested what it could be stored in.

Copper chrome liner to the toilet tank with union nuts. Over the course of 6 years, the black rubber gaskets rotted, became stiff, etc. The gaskets leaked when they touched the pipe. Tightening the new gaskets did not give anything, because the rolling is humpbacked, not polished and corroded - the surface does not provide sealing. We decided to replace it. Due to dampness and corrosion, chrome or nickel is completely covered with rust, inside and out. Photo after several hours in a solution of citric acid 50g per liter.

Source: https://all-audio.pro/c29/stati/flyus-iz-limonnoy-kisloti.php

❌Why can’t you solder parts with acid? Why is acid dangerous?

Category: Soldering 09/05/2019 · : 0 · Reading time: 4 min · Views:

Soldering acid is a highly active flux. Reacts with metal, even after soldering. Corrodes oxides, oxide films and perfectly tins difficult areas.

Radio amateurs and electronics engineers (especially on the Internet) often advise beginners to use acid. This is a fatal mistake.

This flux is easy to tin, but the cost of using such active substances is high.

Advantages and disadvantages of acid

Advantages:

• Good tinning of oxidized surfaces;
• Low price.

It removes oxides perfectly, is available in any radio store, and acetylsalicylic acid is available in a pharmacy.

Flaws:

• The products released during acid soldering are very dangerous (especially if they come into contact with the skin or mucous membranes);
• Residues of acids at the soldering site can damage the connection over time if they are not washed off in time;
• Acid has high electrical conductivity - and this is a short circuit.

Active flux has major disadvantages that are not equal to the advantages.

Radio amateurs most often solder radio components, wires, and printed circuit boards. All this is well soldered with ordinary rosin. At most, a small oxide film may form on the parts due to the oxidation reaction in air, but it is not as critical as oxides from water.

Popular mistakes

Why is it easier to solder with soldering acid? During heating, the soldering area becomes covered with oxides faster, since the higher the temperature, the faster the chemical reactions proceed. Acid also begins to corrode these oxides faster. Here lies another problem. Acid also corrodes the soldering joint, in addition to oxides. This degrades the strength of the connection.

For what reason is soldering with rosin or any other simple flux more difficult? They do not contain active acids, but this does not interfere with excellent soldering without acid.

Poor soldering is preceded by many errors:

• Overheat. The flux evaporates and does not have time to take part in soldering. This happens when the temperature on the soldering iron is set above 300 degrees;
• Underheating This occurs due to the small heating area, lack of understanding of the principles of soldering work, or poor-quality equipment;
• Long touch of the soldering iron to the contact point. Soldering should not last more than a few seconds. Otherwise, most of the flux will evaporate, and the rest of the solder will form a lump and begin to oxidize.
• Amount of flux and solder. An excess or deficiency of components is also a critical factor. Too much flux - the solder will start to spread, too little - it will evaporate quickly and will not be enough for the entire area.

How to solder without acid

To solder efficiently and correctly, just follow simple rules:

• Do not overheat the soldering area. If it seems that tinning and melting the solder is going slowly, it is better to try another tip, try heating the air with a hair dryer to one hundred degrees (on top of the hair dryer, near the soldering point). Under no circumstances should you increase the temperature on the soldering iron to 400 degrees, this will only worsen the situation. Solder at such temperatures begins to evaporate rather than melt, let alone flux.
• Assess the situation. For example, some parts or connectors cannot be tinned well without heating. In especially severe cases, you can even lightly walk over the contact with the softest and most gentle sandpaper. There is such a problem with homemade boards when they are not soldered for a long time after production. Copper traces are plated with copper and are more difficult to tinn than before.
• Safe soldering. Soldering should only be done in a ventilated area. Even the products of rosin evaporation are not very useful, let alone other fluxes, especially soldering acids. When soldering, you must maintain a distance, otherwise a drop of solder may accidentally get on your skin or mucous membranes.

For example, for soldering twisted pairs, a medium tip of the mini wave type and alcohol rosin are suitable. Soldering time is no more than 5 seconds. Is the contact not soldered? Wait until the soldering area has cooled down, apply flux again, and smoothly go over the soldering iron.

For complex cases, LTI-120 is sufficient. This is an activated flux (not active and acid free)

Active flux should only be used as a last resort. Even strong oxides, ordinary acid-free fluxes perfectly clean and tin. There is no need to use any aspirin tablets, acids, or F-38N. To solder the same wires, ordinary rosin is enough.

How to wash off soldering acid

You can remove residues with Galosh gasoline, isopropyl alcohol or soda solution. This can be done using brushes, cotton pads or sticks. It is necessary to carefully remove flux residues without splashing.

Source: https://tyt-sxemi.ru/kislota-payalnaya/