How to solder stainless steel with a soldering iron

How to solder stainless steel: technology for brazing stainless steel

Soldering stainless steel is a rather labor-intensive process, but at the same time there are no great difficulties here. Alloys containing up to 25% nickel and chromium are alloyed together quite simply. Moreover, these alloys can create strong bonds with other metals, with the only exceptions being magnesium and aluminum alloys.

But you need to pay attention to the fact that some nickel-plated alloys when heated to a temperature of 500-700 degrees. Carbides can form; their level of release depends on the duration of soldering, so the procedure time must be reduced.

The resulting carbides significantly reduce the corrosion resistance of stainless steel. In order to minimize the precipitation of carbides, titanium is added or additional heat treatment is carried out upon completion of soldering. Under the influence of hot solder (tinol), the cold-hardened stainless material can crack, so soldering occurs after annealing, without using loads during soldering.

The choice of solder for stainless steel depends entirely on the following characteristics: steel composition, soldering conditions. It should be noted that products that are made in corrosive conditions must be soldered using silver tinols, which contain a small amount of nickel in the composition. Copper, silver-manganese, and chromium-nickel solders are used during oven soldering in dry conditions.

is most often used as a flux for processing stainless steel . It is applied to the joint in powder or paste form. When the borax melts, the rest of the metal gradually heats up to a bright red heat (850 degrees). When this temperature is reached, solder is injected into the joint.

Removal of material adhering to the stainless surface upon completion of soldering is done by rinsing the soldered product in water or by sand blowing. Hydrochloric or nitric acid, which can be used in cleaning, are very undesirable at this stage of working with stainless steel, since they, along with the solder, will corrode the base metal.

Soldering stainless steel at home

Perhaps everyone knows that a home handyman is constantly faced with everyday difficulties that he needs to eliminate on his own. But it often happens that you need to do the work associated with processing stainless steel yourself. Therefore, this will require certain skills, abilities and knowledge. You will also need to acquire some materials and tools. Here is a list of everything you need:

• Soldering acid;
• Electric soldering iron 100 Watt;
• Tin solder for joining metals;
• File or sandpaper;
• A tube;
• Metal cable.

Now that you have decided on the soldering tool, you need to know the steps to perform the actions:

• To process stainless steel, you must initially ensure that you have flux and a 100-watt electric soldering iron. You need to know that there is no point in choosing a more powerful soldering iron for processing stainless steel. The flux is ordinary soldering acid. Also, do not forget to always have tin-lead solder on hand.
• When all the necessary tools and materials are ready for soldering, you can begin work. First you need to clean the stainless steel joint: this can be done using sandpaper or a file. Upon completion of cleaning the work areas, it is necessary to apply soldering acid followed by further treatment. If the treatment does not work (the solder does not stick to the surface of the stainless steel), then you need to re-manipulate the soldering acid on a thoroughly heated surface, then perform the treatment again.
• In the case when you made a second attempt, and it was not successful, and the solder lags behind again, then the working surface of the stainless steel needs to be cleaned with a special brush, which you can make your own: you will need a piece of pipe with a cross-section of 5 mm, where you place thin wires pulled from a metal cable . Now, apply acid to the soldering area, and then bring the brush and soldering iron here at the same time. Then start working with two tools. It should be noted that this process is very helpful in removing the oxide film from the surface of stainless steel.
• When the parts have been tinned, begin soldering stainless steel using a soldering iron and flux.

Soldering with a gas torch

The parts are heated using a gas torch or a tin-plated soldering iron tip. When working with the burner, you must ensure that there is not too much oxygen in the flame, because this causes the stainless steel to oxidize. This can be determined by the color of the fire (it should be blue); if the color is pale and the fire is weak, then this indicates an excess of oxygen. To warm up the connection, the burner must be moved smoothly.

By periodically touching the metal with solder, the quality of the temperature achieved is determined. Heating is sufficient when the solder melts not from the flame of the torch, but from touching the metal.

Then solder is immediately applied to the part where the joint needs to be made, while the parts continue to be heated so that the solder, melting, slowly fills the joint completely . If there is not enough liquid solder in some area, it is heated more strongly than other places, and the solder itself flows into it. A clear sign of high-quality soldering is the leakage of excess solder from the joint.

Working with hard solders

Stainless steel soldering works well using flowable, liquid, fluxed solder with a low melting point and high capillary characteristics. This solder is quite elastic and has excellent deoxidation properties, which are very useful when working with stainless steel.

It can also handle brass, copper and some other materials. Soldering with such hard solders is very suitable for stainless steel. Stainless steel does not contain cadmium, and the percentage of silver here is 30%. Processing the material with hard solders gives good results, making it possible to obtain durable and high-quality metal fastening.

HTS528 solder can cope with copper, brass, nickel, bronze, stainless steel, and other metals. Along with other hard solders today, this tinol is the most in demand. The solder looks like a rod treated with red flux. The rod size is about 45 cm , and the weight is 20 g. The melting point is 760 degrees.

How to choose a flux for soldering

Small elements are soldered with adjustable gas-air burners (this method is more suitable for jewelry). Larger parts are best soldered with acetylene. The same applies when choosing a flux for stainless steel, since this metal is very demanding on flux. Flux for stainless steel consists of 10% calcium fluoride, 20% boric acid, 70% borax .

For small stainless steel parts, you can prepare a flux composition that includes 50/50% boric acid and borax. This flux must be diluted in water, then applied to the part; when it dries, the solder will adhere perfectly to the metal surface.

That is, the soldering area is not etched, but only cleaned using sandpaper. Copper does not spread well over the surface of steel, so it is better to use L 63 brass. For better soldering, you can also use silver and brass to make solder from them.

Recommendations from professionals

There are many people who, so to speak, “ate the dog” when working with soldering. And they share personal experience gained in practice, giving useful recommendations:

• It is best to choose a soldering iron with a non-burnable tip.
• An electric soldering iron needs a power of 60-100 watts. The most optimal soldering iron is 100 Watt. A less powerful soldering iron will not be able to heat the metal.
• Phosphoric acid works best as a flux.
• It is advisable to use tin-lead rods as solder. You can also use tin in its pure form. It must be said that it is better to solder utensils with tin, since pure tin does not contain lead.
• When working with soldering, it is necessary to use personal protective equipment.
• Soldering must take place in a well-ventilated and open area.

Basic mistakes during soldering

If an error is made during preparation, selection of materials, or during the soldering process, the solder may not spread over the surface and may not hold the parts together. It happens that the parts were not properly cleaned or were not heated up properly. This often happens with large-sized products. The tip of the soldering iron must be thoroughly cleaned after any session, and in order for jewelry work to be possible, its tip must be sharpened from time to time.

To obtain a high-quality connection, do not solder stainless steel with pure lead or use rosin. If the solder is made of tin, then working with it can be quite difficult due to its weak consistency. If the tin does not melt more than to the state of warm plasticine, then most likely it will not hold the connection, constantly breaking and crumbling. The optimal state of tin for fastening is if it looks like a liquid.

High-quality solder, which is laid according to all the rules, can only be scratched , but not separated from the stainless steel soldering area. In order not to damage the connection in the future, after soldering the product must be allowed to cool down at rest. When the joint has cooled, it is cleaned of any flux and solder that remains at the edges, and then washed thoroughly with soap.

Source: https://stanok.guru/metalloprokat/nerzhaveyuschiy-prokat/kak-payat-nerzhaveyku-i-tehnologiya-payki-tverdym-pripoem.html

How to solder stainless steel at home?

Soldering stainless steel is a rather complicated procedure. It is used to connect thin-walled parts when it is not possible to perform TIG welding. This avoids excessive temperature exposure to the work surface.

Features of alloys

Soldering stainless steel is classified as skilled work . This is due to the fact that in order to select the optimal soldering mode, it is necessary to accurately determine the type of material. For example, riveted grades of stainless steel are soldered without load, in order to avoid the formation of defects on the surface due to temperature exposure.

Aluminum and magnesium interact weakly with the alloy in question, so when selecting a material you should pay attention to the composition of the product. Stainless steel forms a highly durable connection with other types of metals.

Highly alloyed compounds with a high chromium content do not withstand high temperatures. When heated above 500 Cº, the formation of chromium carbide is activated, which negatively affects the parameters of the metal.

Solder selection

The correct solder for soldering stainless steel is the key to the quality of the connection. The following factors influence the choice of suitable material:

• metal composition;
• working conditions.

Under standard conditions, soldering is performed with silver solder - it has excellent anti-corrosion properties, and the nickel in its composition increases the strength of the connection. Visually, the connection will not differ from the main surface. Craftsmen consider silver compounds to be the best material for soldering stainless steel. However, it is prohibited to use silver without additives. To improve the quality of the connection, copper or zinc is added to it.

Flux selection

Not every flux is suitable for working with stainless steel, since the process takes place under the influence of high temperatures. Experienced craftsmen recommend using borax . It is introduced into the contact zone and heated until completely melted, after which solder is supplied.

In the absence of borax, it is recommended to use phosphoric acid as a flux. More active compounds will negatively affect the solder layer.

How to make flux with your own hands?

Experienced craftsmen prefer to prepare flux with their own hands. There are several recipes. The most common mixture is considered to be one that includes:

• borax – 7 parts;
• boric acid – 2 parts;
• calcium fluoride – 1 part.

The mixture is prepared on a water basis.

To work with small parts, just mix boric acid and borax in a 1:1 ratio.

Features of tin soldering

Solders based on tin-lead mixtures are distinguished by high quality connections at an affordable price . This is the main reason for the popularity of soldering stainless steel with tin at home.

The method has proven itself best when sealing small cracks or connecting small parts. Products subject to temperature loads during operation are recommended to be soldered using silver compounds.

An example is distillation tubes, which are operated at high temperatures under pressure.

The use of tin as a filler material when soldering stainless steel is not widespread in industry due to the low temperature threshold of the connection.

Advantages

The use of low-melting solders has the following advantages:

• easy procedure for soldering small parts;
• preparatory procedures do not take much time;
• low cost of consumables;
• You can use either a household electric soldering iron or a gas burner.

Flaws

The method has the following disadvantages:

• low connection strength;
• the low melting point of tin reduces the scope of application of sealed parts;
• competent use of molten tin requires certain professional skills from the master.

Modes

Tin-lead solders are used with the following parameters:

• the maximum burner temperature is 240 Cº;
• minimum power of the soldering device – 40 W;
• surface exposure interval – no more than 10 seconds;
• The thickness of the solder, regardless of the form of manufacture, should not exceed 4 mm.

How to work at home correctly?

Soldering stainless steel is considered a rather complex process, so work at home should be approached with special attention. Most solders, with the exception of tin, require a soldering iron of at least 100 watts .

Do not forget about preparing the surface for soldering. This procedure begins with mechanical processing of the plane and ending with its tinning.

The use of active fluxes requires special attention - after completion of work, it is necessary to rinse the connection with running water.

Connection with other metals

When soldering dissimilar compositions, for example, soldering stainless steel with copper or bronze, it is necessary to carefully study the properties of the metals being joined . The main problem is the selection of temperature parameters, since the workpieces have different melting conditions.

Regardless of the type of metal, the contact area must be thoroughly cleaned.

As a working tool, you can use a soldering iron or a torch.

If silver solder is not available, brass-based compounds can be used. This will reduce the quality characteristics of the connection, but will allow you to save on consumables, since brass is cheaper than silver.

Food solders

The requirements for soldering utensils used for cooking do not differ from the general rules for carrying out work. Proper solder for stainless steel is a basic requirement. For example, POS group solders cannot be used to repair cookware, since lead negatively affects human health .

Basic mistakes

The slightest mistake can lead to a significant decrease in the quality of the connection. The following tips will reduce the likelihood of errors:

1. When doing homework, the optimal soldering iron power is 100 W. Using a more powerful device will lead to overheating of consumables, and a less powerful one will lead to incomplete heating of the metal.
2. Use a soldering iron with a non-burnt tip.
3. It is better to solder food utensils with pure tin, since lead has toxic properties.
4. Experienced craftsmen recommend using active compounds as flux. Orthophosphoric acid has proven itself best.

Conclusion

Soldering stainless steel is a complex procedure due to the variety of alloying alloys. For small parts that are not exposed to temperature, POS group solders are best suited.

Source: https://svarka.guru/payka/tehnik/nerzhaveyki.html

How to solder stainless steel with a gas torch?

Those who have worked with stainless steel know that soldering this material is not easy. This process has certain features, knowing which you can avoid mistakes and controversial issues when connecting parts. Soldering stainless steel is a process that is accessible not only to experienced craftsmen, but also to beginners. It is important to choose the right tools, consumables and follow a certain procedure.

Inventory

To carry out the work, you need to prepare all the necessary tools in advance. If soldering steel is carried out at home, you need the following equipment:

1. Electric soldering iron. The optimal power of the equipment is 100W. As a similar option, you can use a hand-held propane torch.
2. Solution for degreasing the working surface.
3. Flux for soldering.
4. Tin based solder.
5. Rags.

We must not forget about personal protective equipment - safety glasses, gloves, a work suit and a respirator.

Solder Types

Solder for soldering stainless steel is considered the main consumable material when carrying out work. There are two groups of solders:

1. Soft - mixtures made from lead and tin. These materials increase the ductility and fluidity of the consumable material for creating a connecting seam. The disadvantage of soft compositions is the low strength of the hardened material.
2. Solid - used in workshops and enterprises. The compositions contain 30% technical silver, thanks to which the connection is strong and durable.

Flux preparation

Proper soldering of stainless steel requires a competent choice of flux. This is due to the fact that alloys that are resistant to corrosion processes are easily damaged during the welding process. To avoid mistakes when choosing a purchased mixture, you can prepare it yourself. Making flux:

1. Take a portion of borax and the same amount of boric acid.
2. Mix the ingredients together.
3. Dilute with clean water.
4. Stir until a homogeneous mass is formed.

The finished composition is applied to the adhesion site. After drying, the adhesion rate to the treated surface increases.

Homemade fluxes are not inferior to purchased compounds. To increase its effectiveness, before applying the substance it is necessary to treat the metal surface with sandpaper or a file.

Features of work at home

Stainless steel products are found in most apartments and houses. If they break, you can try to connect the parts yourself. Soldering stainless steel at home requires not only the preparation of tools and consumables, but also skill. For the first time, it is better to train on products that you don’t mind throwing away.

To carry out work, you need to equip a workplace. Soldering must be done on a non-flammable surface that does not transfer heat. A ventilation system must be installed in the room to extract flux and solder fumes. It is necessary to place a vice or clamps on the workbench to clamp the parts being fastened.

Soldering iron technology:

1. Soldering stainless steel with an electric soldering iron begins with cleaning the working surface and degreasing it.
2. Next, flux is applied to the joint.
3. Solder is evenly distributed over the surface to be joined using a soldering iron.

There are situations when the solder does not want to stick to the material. To correct this problem, you need to re-clean the surface with a wire brush and degrease it.

If work is carried out using a gas burner, you need to take into account some features. It is necessary to heat the workpiece, and not the joint of the parts. This way the solder melts evenly and does not spread to the sides. Heating should be completed after the solder flows out of the seam.

Disadvantages of brazing stainless steel

Tin-based brazing alloys for soldering stainless steel have significant disadvantages:

1. Low strength of the finished connection.
2. The temperature that the material withstood is reduced to the melting temperature of the solder.

Due to the high fluidity of solid solder when heated, it is difficult to work with it on vertical surfaces.

Useful tips

Soldering steel is a labor-intensive process, during which controversial issues may arise. In order not to get hung up on them, you need to take into account the advice and recommendations of other masters:

1. An electric soldering iron with a power of 100 W is enough for home repair work. It is advisable to choose a model with a non-burning tip.
2. The best type of solder are rods made from an alloy of lead and tin. If you need to repair a crack in a pot, you need to use tin solders.
3. The ventilation system will protect the respiratory tract from diseases associated with inhalation of harmful impurities.

You need to practice on spoons, cups and old bowls. You can use waste from the production of galvanized castings.

The most common mistakes

There are a number of mistakes that a person can make when carrying out work:

1. Solder may not adhere to the material due to poor cleaning of the work surface.
2. Contamination of the part with greasy fingers before applying flux.
3. Insufficient heating. Solder does not always have time to fill the seam for reliable bonding.

It is important to remember to clean the soldering iron tip. It is advisable to refrain from using solders with a high percentage of lead.

Soldering stainless steel is a difficult process, but it can be done. To successfully connect parts, you need to choose the right consumables and use high-quality tools.

Source: https://rem-serv.com/kak-payat-nerzhaveyku-gazovoy-gorelkoy/

How to solder stainless steel to stainless steel? How to solder with a soldering iron with rosin and tin

How to solder stainless steel to stainless steel using tin and rosin? This is a very labor-intensive process, for which you need to know all the subtleties and tricks of soldering work. If you follow the instructions discussed in this article, you will be able to make a reliable connection of stainless steel products.

Process Features

For work with food containers, you can only use lead-free solders (for example, tin and alloys based on it). Soldering stainless steel products is a complex process that requires some knowledge and skills to perform.

The best solder for working with the mentioned metal is tin. Thanks to this material, it will be possible to make a high-quality connection. However, tin is more often used for soldering when small parts need to be attached or small cracks need to be repaired.

Solder is sold in coils or in the form of bars 2–4 mm thick.

In industry, soldering using tin is rarely used. And at home, to repair household items (for example, a stainless steel kettle), they use a soldering iron or a gas burner, as well as the mentioned solder. In this case, the main thing is to prepare the necessary consumables (consumables). But we should not forget: during soldering work, hot objects and toxic substances will be used, so you must follow safety rules.

Why do you need flux?

This substance will ensure uniform spreading of solder over the surface of the soldering zone and create conditions for high-quality adhesion of the material to the metal coating. Fluxes are currently classified according to the degree of impact on the following varieties:

1. Inactive (neutral), which do not contain acids. In addition, they almost do not conduct electricity.
2. Active (acid) fluxes.
3. Protective (anti-corrosion), the purpose of which is to protect the soldering zone of the finished joint from corrosion and destruction.

If the question arises why flux is needed for soldering, then the answer can be this: this substance is necessary to comply with the technology, since it will definitely be needed during soldering work. However, the method of application of the composition depends on its initial state:

• if the flux is in a solid state, the soldering iron tip must first be dipped into the reagent, and then grab a little solder with it;
• the finished liquid mixture will have to be applied to the soldering area using a brush;
• The surface should be treated with a paste-like substance using a regular stick.

In addition, flux is sometimes sold in special tubes.

Necessary equipment

Before you begin repairing the product, you need to prepare the following tools and materials:

• A simple soldering iron (minimum power - 100 W) or a propane torch.
• Organic solvent (for example, white spirit or acetone).
• Tin solder.
• Rosin or phosphoric acid.
• Steel rope.
• Metal brush, file or sandpaper.
• Clean cloth for wiping.

However, before soldering stainless steel to stainless steel and, accordingly, repairing the part, you should purchase protective equipment: polyurethane gloves, goggles and a respirator.

In addition, to connect large products, a more powerful soldering iron may be required, the tip of which must be fireproof: this will not only increase the service life, but also improve the technical parameters of the tool.

Regarding solder, it should also be said that tin bars are suitable for soldering food utensils or other containers, since they contain fewer harmful impurities.

When the materials and tools are prepared, you can begin this operation. To solder stainless steel at home, you need to follow these step-by-step instructions:

1. Use sandpaper or a brush to remove oxide film and other contaminants from the metal surface.
2. Degrease the part to be repaired with solvent.
3. Apply flux - rosin or soldering acid - to the surface to be treated. This step does not need to be performed if a combined tin solder is used, which already contains the mentioned substance. Flux must be applied immediately before soldering, since a film forms on the surface of the stainless steel after about 10 seconds.
4. Heat the soldering area on which the flux is applied with a tinned soldering iron tip.
5. Add solder if necessary, but most likely you won’t be able to cover the entire surface with tin the first time.
6. Reapply flux and heat it again with a soldering iron. Repeat this process until the surface of the metal is covered with an even layer of tin. The main thing is that the solder melts not from the tip of the soldering iron, but from the heat stored in the part. In addition, to make the soldering of stainless steel with tin better, you need to add rosin to the joints, which will remove oxides from the solder.
7. Wash the product from flux residues. To complete this step, you need to prepare a solution consisting of water and detergent and buy metal scrapers. The remains of rosin, according to the masters, can be easily cleaned with cold water, since the substance becomes brittle in it.

Soldering is considered high quality if the result is a uniform surface. But in any case, at the end the coating must be sanded with sandpaper or a file.

How to join stainless steel parts: optimal technique

First you need to equip your workplace. The table must be steel or have a non-flammable surface. The main thing is that it is even. In addition, you need to make high-quality exhaust ventilation. In turn, in order to solder several products into one at home, you need to cover their parts with tin and fix them together. The next step is to heat the parts at the same time so that the hot solder bonds. You will probably have to add tin to the soldering area by placing it on the soldering iron tip.

After this, you need to warm up the entire surface and, if the solder is applied well, you need to place the parts on a flat surface. A stainless steel product assembled from two or more parts must not be moved until the joints have completely hardened. It is better to secure the soldered parts with fastening devices (for example, clamps or a vice).

Soldering with a gas torch: repairing a kettle

First, you need to thoroughly clean the soldering area with sandpaper and remove scale near the damaged area. To solder a stainless steel kettle with a gas burner, you need to follow these instructions:

1. Heat the connection with a flame, smoothly moving the device. The heating will be sufficient when the solder begins to melt upon touching the metal.
2. Apply flux (rosin or phosphoric acid) to the soldering area.
3. Apply tin to the damaged area, while continuing to heat the area with the burner so that the substance melts and fills the entire defective area.
4. Sand the seam with a metal brush.
5. Wipe the sealed area with alcohol to clean its surface from scale and oxides.

During soldering work, you need to monitor the oxygen level. To determine this parameter, you need to look at the flame, the normal shade of which is blue. In an oversaturated composition, the color will be pale, which indicates an excess of oxygen. If you ignore this requirement, there is a high probability that the stainless steel will begin to oxidize.

Advantages of soldering stainless steel with tin

The advantages of this method include the following properties:

• consumables are inexpensive;
• no lengthy preparation of the part is required;
• simple soldering work for small-sized products;
• tin solder reduces the fluidity of stainless steel during soldering;
• good connection quality.

How to solder stainless steel

Sometimes brazing stainless steel is preferable to welding. Soldering is used for thin-walled products that are not subject to heavy loads, and in cases where they do not want to experience warping from heating.

It should be taken into account that some types of stainless steel require a certain approach, taking into account their composition and manufacturing technology. For example, cold-worked stainless alloys crack at high temperatures, so their soldering is carried out without loads, after first annealing the metal. There are other subtleties.

How to solder correctly at home

In order to properly solder two stainless steel workpieces together, you need to properly prepare for the process. To do this, it is better to use orthophosphoric acid or zinc chloride, which is usually called soldering acid, as a flux. A soldering iron needs a power of 100 W. As for solder, it is easier to solder stainless steel with tin at home.

The first stage of the process is to clean the edges of the two stainless steel parts. To do this, use sandpaper or a file with fine notches. Then you need to tinning the prepared edges.

To do this, the planes to be joined are treated with flux, then the solder is heated with a soldering iron, which is applied to the ends of the two workpieces. The solder should remain on the soldering iron tip, and from it should be transferred to the planes that are to be tinned.

If the tin does not stick to the stainless steel, then the procedure must be repeated, preheating the ends of the parts to be connected.

Once tinning has occurred, you can proceed to soldering by adding flux and solder to the joint area. At the end of the process, the acid is washed off with water.

Useful tips

Experts who have had the opportunity to solder stainless steel more than once assure that this process is not so complicated. Here are some recommendations from them when using a soldering iron:

• For soldering you need to use a soldering iron with a non-burnable tip;
• The power of the tool varies in the range of 60-100 W, optimally 100. You should not use higher than that, overheating of the workpieces means overheating of the solder, which will begin to boil. Below is also not desirable, because molecular bonds will not form between all the metals that participate in the soldering process;
• It is recommended to clean the tool tip after each operation. Sometimes you have to sharpen it;
• It is better to solder with tin rods or tin-lead rods. The second type is not used for joining food grade stainless steel. Pure tin solder will have to be heated well, at least to the consistency of softened plasticine. In general, the metal must be liquid; it is in this state that it can stick to the steel;
• Phosphoric acid is used as a flux. Rosin, due to its neutrality, is not used for stainless steel;

It is imperative to adhere to safety precautions, especially if soldering is carried out at home. It is necessary to use personal protective equipment, as well as organize ventilation of the room.

As you can see, there are many caveats. But taking them into account, we can talk about the high quality of the final result.

Source: https://svaring.com/soldering/tehnologii/pajka-nerzhavejushhej-stali

Principles of soldering stainless steel at home

Those who have worked with stainless steel know that soldering this material is not easy. This process has certain features, knowing which you can avoid mistakes and controversial issues when connecting parts. Soldering stainless steel is a process that is accessible not only to experienced craftsmen, but also to beginners. It is important to choose the right tools, consumables and follow a certain procedure.

Soldering stainless steel pipes

Soldering stainless steel

Soldering stainless steel is quite a complex and difficult job. To make a high-quality connection, you need to comply with many conditions - both in the choice of materials and in the soldering modes. It is somewhat easier to solder alloys containing up to 25% Ni or Cr. They can also be soldered to other metals and alloys, with the exception of Al and Mg. DIYers most often use tin solders.

Soldering stainless steel

Features of stainless steel soldering

Using tin and compounds based on it, you can repair stainless steel products, as well as assemble homemade structures that are small in size and not subject to heavy loads. Kitchenware and other household items can be repaired with a regular soldering iron and tin solder.

Soldering of stainless steel in production is performed using a more complex technology. For soldering of critical structures, special industrial mixtures containing Cr < Ni, Mn, chromium, nickel, and manganese are used. You have to work with them in a protective gas atmosphere - argon with the addition of boron trifluoride. Pure copper is used as solder when soldering stainless steel.

Equipment used

In order to properly repair products, you need to prepare materials, equipment and study technology. To solder stainless steel in a workshop at home, you will need:

• electric soldering iron with a power of 100 W (portable propane torch);
• flux;
• degreaser (solvent);
• abrasive paper, wire brush, needle file;
• tin solder;
• rags;
• protective equipment: gloves, respirator, safety glasses or transparent face shield.

Portable propane torch

In addition, for the initial heating of massive workpieces, a more powerful soldering iron may be needed. Phosphoric acid provides high-quality surface cleaning and rapid coagulation.

Solder Types

Solders for stainless steel are divided into two main groups:

Soft ones are the usual compositions based on Pb and Sn grades POS. Sufficient tin content increases ductility and fluidity, allowing it to penetrate into all micro-irregularities of the surface and significantly improving adhesion. In addition, tin is a good deoxidizer, which is especially important when working with stainless alloys. The disadvantage of such soldering compositions is the low strength of the resulting joint.

To obtain stronger solder joints on stainless steel, hard solders are used. They are used both in industrial conditions and in the home workshop. Up to 30% technical silver is added to solid compositions. They are produced in the form of thin rods and are designated by the letters PSR.

Solder HTS – 528

If you need to solder together dissimilar products made from materials such as stainless steel, copper alloys, nickel, cast iron, use the HTS-528 composition. It already contains flux, and the melting point is not less than 750 ° C

Flux preparation

Corrosion-resistant alloys are very sensitive to soldering conditions, so the correct choice of flux for soldering stainless steel is extremely important.

The most widely used flux contains:

• 7 parts technical borax;
• 2 parts boric acid;
• 1 part calcium fluoride.

Making flux at home

For soldering small workpieces, the composition of the flux is simplified - equal parts of borax and boric acid are taken. The mixture is diluted in water and applied to the soldering area. Once it dries, it will provide excellent adhesion to the surface of the alloy.

Before applying flux, it is necessary to thoroughly mechanically treat the soldering area with sandpaper, a wire brush or a needle file.

Advantages of soldering stainless steel with tin

The use of soft tin-based compounds provides the following advantages:

• ease of soldering operations for small objects;
• short preparation;
• availability of soldering materials;
• Sufficient soldering quality for not the most critical parts.

Soldering stainless steel with tin

Soldering with soft tin compounds can be quickly mastered by a home craftsman.

Disadvantages of soldering stainless steel with tin

In addition to the advantages, soldering stainless steel with tin also has disadvantages

• low connection strength;
• lowering the maximum operating temperature of sealed items to the plasticity temperature of tin;
• difficulties during soldering caused by the high fluidity of tin.

Due to its high fluidity, it is difficult to seal seams on vertical and inclined surfaces.

Tin soldering modes

The soldering modes recommended by experienced specialists are as follows:

• Burner temperature: 232-240 °C;
• Soldering iron power 80-120 Watt;
• Warm-up time 5-10 seconds;
• The thickness of the solder bar is 2-4 mm.

It is convenient to control the flame temperature with a pyrometer.

Preparation of equipment and necessary materials

When preparing equipment, it is important to pay attention to the characteristics and design features of the soldering iron. Its power is at least 80-110 watts; weaker devices will not be able to provide sufficient heating of the working area. The sting must be fireproof.

You can work with a soldering iron using soft, low-melting solders - rods made of pure tin or from mixtures like POS. Pure tin will be needed when repairing kitchen utensils and vessels that come into contact with food or drinking water. It does not contain harmful components.

The most suitable flux for such dishes is phosphoric acid.

For hard solders you will have to use a gas torch.

Selection of solder and auxiliary materials

The correct choice of composition allows high-quality soldering of stainless steel parts. Such a connection will be reliable and durable. The most common types of soldering compounds are tin-lead POS grades. For soldering work on stainless steel, experts recommend:

• POS50Kd18 (with the addition of cadmium);
• POS-61;
• POS-40.

Only clean tin should be used to repair items that come into contact with food. Not every flux is suitable for stainless steel.

Solder POS-61 Phosphoric and soldering acids

Commonly used:

• soldering acid;
• orthophosphoric acid ;
• zinc chloride.

It is necessary to apply flux immediately before soldering, so that the oxide film does not have time to re-form.

Interesting: Phosphoric acid is part of Coca-Cola. A good reason to think about whether you should drink it.

Technology of soldering stainless steel with tin

It is very important to carry out the preparatory operations correctly and carefully. Their purpose is to remove oxide film and other contaminants from the surface of the stainless steel that prevent the formation of a strong and durable solder joint.

First, the surface is protected with sandpaper, a wire brush or a file. Next, after removing sawdust and abrasive particles, degreasing is carried out. To do this, take a special degreaser.

It can be successfully replaced by any organic solvent - acetone, white spirit, numbered solvents (646, 657), etc.

Immediately after degreasing, the soldering area is coated with a flux compound. (If flux is included in the solder rod, this step is not performed.)

Now the actual tin soldering begins. First, the soldering area is heated using a soldering iron tip or a gas torch. When soldering with a torch, the oxygen content should be monitored, since if it is in excess, oxidation processes will begin, deteriorating the quality of the connection. When the permissible oxygen concentration is exceeded, the flame acquires a light blue tint.

The principle of soldering stainless steel

The entire soldering area should be heated to the melting temperature of the solder.

Important! The solder should melt not from the tip of a soldering iron or the torch of a gas burner, but from the heat stored in the parts being soldered.

Solder must be supplied to the working area until it begins to appear from the working gaps between the workpieces. This will ensure optimal adhesion.

Soldering stainless steel at home

It often happens that a home handyman needs to repair household utensils and stainless steel dishes. To do this, it is necessary to prepare a certain set of equipment, as well as working and auxiliary materials.

In order to quickly and efficiently repair stainless steel products, you will also need to acquire a certain skill. Therefore, you should not immediately take on the repair of complex or large-sized products.

To get better at “feeling metal and fire,” it’s better to practice on spoons, mugs, or just scraps of stainless steel.

Soldering stainless steel at home

To work, you will need to equip a workplace. The work table must be metal or have a non-flammable coating. Exhaust ventilation must be equipped - both the fumes from the soldering compound and the flux and degreaser are harmful to the respiratory system. The parts to be soldered must be securely fastened with inventory fastening devices - vices, clamps, clamps, spacers.

The work area should not be cluttered; only parts to be soldered may be contained in it.

Containers with working fluids should be tightly closed immediately after use and stored in a cabinet or bedside table.

It is necessary to carefully follow the technology for performing the work. If the processing is carried out poorly and the solder does not stick to the surface of the parts, it is necessary to stop soldering and repeat mechanical processing and degreasing. After degreasing, you can handle parts only with thick gloves - even a small sweat stain left by your fingers can ruin the work.

You can make your own wire brush for stripping. To do this, wires obtained from a piece of metal cable must be tightly inserted into a piece of pipe with a diameter of 5-10 millimeters and a length of about 10 cm. They should protrude from the tube by a few millimeters. For small soldering areas of stainless steel, and especially in narrow and hard-to-reach places, such a homemade product is much more convenient and effective than purchased brushes with a wooden handle.

This brush can be used to work in close proximity to a soldering iron or burner flame, minimizing the time between stripping and the start of soldering.

Common Mistakes

The most common mistake when soldering stainless steel is

• poor cleaning;
• insufficient defatting;
• insufficient heating of the parts, as a result of which the solder did not penetrate into all the gaps and did not connect them.

It is necessary to periodically clean the soldering iron tip.

Do not solder with compounds containing high lead content or use rosin.

You can check the quality of the connection by trying to pick it with an awl or screwdriver. A reliable connection can only be scratched; it will not be possible to peel off the solder from the stainless steel.

Cleaning stainless steel after soldering

After the soldering has cooled, clean off any remaining soldering compound and flux. Stainless steel food utensils should be washed with warm soapy water and boiled before use.

Source: https://stankiexpert.ru/spravochnik/svarka/paika-nerzhaveiki.html

How to solder stainless steel with tin

There is a misconception that it is impossible to solder stainless steel with tin, since the process is labor-intensive and very difficult. But this is far from true: such work can be done even at home if you have certain knowledge, skills and experience.

So, if you purchased high-quality stainless steel from the MetalCity company and you need to solder it, then use the information and tips given below.

The main thing is a soldering iron!

Before you begin, consider whether you should actually solder rather than use other fastening methods. Soldering is advisable if metal parts cannot be drilled or the bolted connection is unreliable.

The main factors that influence the process: a good electric soldering iron and the right flux, which ensures the connection of surfaces for a long time.

Pay special attention to the following:

1. The power of the soldering iron should be 60-100 W; if it is less, then it will not be possible to heat the metal well and melt it to the desired state. High power at home is not needed - it leads to excessive energy consumption.
2. You need to purchase a soldering iron with permanent heating - it lasts a long time and saves energy.
3. It is best to have a soldering iron with a tip that does not burn - this will work longer. It needs to be descaled periodically, and also sharpened for precise work.
4. Tin is an almost ideal solder for stainless steel. It does not contain lead, like POS, and can be used with products in contact with food.
5. Without the correct choice of flux, it is impossible to tin stainless steel, as an oxide film will form. The best flux in this case is phosphoric acid.

He who doesn't work doesn't make mistakes

For soldering, the tin must reach the desired consistency - similar to water. Then the seam turns out to be of high quality, even and long-lasting.

Mistakes in achieving a good result are:

• the soldering iron has not reached the required temperature;
• poor heating of the parts being soldered. If they are large, then this can be done using a gas burner or on an electric stove;
• incorrect choice of flux, which cannot dissolve the oxide or fatty film on the metal.

All the above-described features must be observed when soldering stainless steel with tin. After finishing work, the connected surfaces should be washed with soap and water. The fact is that the acids used in the process are quite aggressive, they accelerate the destruction and corrosion of the metal, and soap neutralizes them.

Source: http://euroelectrica.ru/kak-payat-nerzhaveyku-olovom/

How to solder with a soldering iron with rosin and tin: technology

When the materials and tools are prepared, you can begin this operation. To solder stainless steel at home, you need to follow these step-by-step instructions:

1. Use sandpaper or a brush to remove oxide film and other contaminants from the metal surface.
2. Degrease the part to be repaired with solvent.
3. Apply flux - rosin or soldering acid - to the surface to be treated. This step does not need to be performed if a combined tin solder is used, which already contains the mentioned substance. Flux must be applied immediately before soldering, since a film forms on the surface of the stainless steel after about 10 seconds.
4. Heat the soldering area on which the flux is applied with a tinned soldering iron tip.
5. Add solder if necessary, but most likely you won’t be able to cover the entire surface with tin the first time.
6. Reapply flux and heat it again with a soldering iron. Repeat this process until the surface of the metal is covered with an even layer of tin. The main thing is that the solder melts not from the tip of the soldering iron, but from the heat stored in the part. In addition, to make the soldering of stainless steel with tin better, you need to add rosin to the joints, which will remove oxides from the solder.
7. Wash the product from flux residues. To complete this step, you need to prepare a solution consisting of water and detergent and buy metal scrapers. The remains of rosin, according to the masters, can be easily cleaned with cold water, since the substance becomes brittle in it.

Soldering is considered high quality if the result is a uniform surface. But in any case, at the end the coating must be sanded with sandpaper or a file.

Recommendations

Naturally, without a good soldering iron and flux, you won’t be able to make a reliable connection. However, before soldering stainless steel, you need to consider other points:

1. It is advisable to buy a soldering iron with a tip that does not burn: the service life of such a tool is longer than that of a conventional device. However, it must be constantly descaled and sharpened. In addition, it is recommended to use a soldering iron with constant heating: this will save energy.
2. Soldering stainless steel without flux is a bad idea, since an oxide film will constantly appear.
3. Inexperienced craftsmen should practice a little on unnecessary parts and scraps. You need to remember: a reliable connection is difficult to tear off, and you can check its quality using a screwdriver or an awl.
4. A part treated with a solvent should only be touched with gloves, since a small stain left on the surface can ruin the entire work.
5. Before soldering stainless steel to stainless steel, you need to provide the room with good ventilation. In addition, do not touch heated metal or solder with your hands, or inhale toxic fumes.
6. Containers with substances must be immediately closed with a tight lid after use.
7. The finished part must be cleaned of flux and soldering compound. Food containers are treated with soapy water and boiled to neutralize aggressive acids.