Many are sure that at home it is impossible to make a good soldering iron on your own, which would not only not be inferior to factory samples, but also surpass them. And this, of course, is true, but with one caveat: such a task is impossible only for those who do not own a set of simple technological techniques and tricks. In this article, I share my experience and talk in detail about home technologies that make the impossible possible.

1. Sometimes it's easier to make than to buy.

In the arsenal of a good electronics engineer, the tool should be very different. This also applies to soldering irons. It is impossible to get by with one soldering iron for all cases. There are usually no problems with powerful soldering irons: there is enough of this stuff for sale for every taste. But with their "younger brothers" it is more difficult. However, it is more correct to talk not about power (it should also ideally be adjustable), but about the diameter of the sting and the distance from the tip of the sting to the handle. Power is often talked about as the main criterion, simply for the reason that soldering irons with a thick tip are designed to work with massive parts that have a large thermal capacity - the tool must develop a sufficiently large power to warm them up. And vice versa, for the smallest installation, soldering SMD components and chips with small pin pitch required miniature soldering iron with very thin sting. Such a soldering iron does not need high power, because the thermal capacity of the parts in this case is very small. At the same time, the smaller the distance from the tip of the tip to the handle, the more accurate the movements during soldering. This is especially noticeable under a microscope. But with a long soldering iron, the likelihood of a miss is much greater, and, for example, "glue" two closely spaced tracks or pins on the microcircuit, and then spend time eliminating such a defect. And in small installation this is very difficult.

That's all you need to make a soldering iron!
1 - wooden block (material for making a handle); 2 - a can of condensed milk (mild steel for the body); 3 - silicate glue (liquid glass - a binder for a heat-resistant composite); 4 - coil of thin steel wire; 5 - mild steel about 0.5 mm, often called galvanized iron; 6 - wire trimmer resistor (source of high-resistance wire for the heater); 7 - a piece of copper winding wire for making a sting; 8 - asbestos cord (fiber for heat-resistant composite).

The photo does not show only an electric wire, a small piece of fiberglass, as well as 10 centimeters of any thread and a drop of BF glue. All other materials used are shown in the photo.

Electronics keeps getting smaller and smaller. Today, a sting even 1 mm in diameter seems thick in some cases. In hardware stores, soldering irons with a power of less than 25 W and a tip diameter of less than 4 to 5 millimeters are rarely found. For such a product, it is better to contact specialized stores. You can also search online stores. In general, interesting samples can be found. But even with these samples, as a rule, something is wrong. Not a single "spoon of honey" is insured against a "barrel of tar". For example, I do not understand the fashion for stings with a conical working end made of some hard-to-work alloy. Such stings (if not sharpened, but it seems impossible to sharpen them) do not have a working edge and are poorly wetted with solder. But I would like, as the poet said: "And fingers ask for a pen, a pen for paper." Only in our case, instead of a pen, a soldering iron, and instead of paper, you know what. Yes, a soldering iron should inspire inspiration by its very appearance. And what? Technical creativity also requires inspiration. It is also a kind of art.

In general, you can look for a ready-made soldering iron and adapt to its shortcomings, or you can make your own soldering iron by adapting it to your preferences.

2. The main difficulties in the manufacture of a soldering iron

In order for the soldering iron to serve for a long time and flawlessly, it must have the necessary mechanical strength, and its electrical connections must be reliable. In this case, it is necessary that the heater is isolated from the body and the tip (even with low-voltage power!). High requirements are also placed on the reliability of this insulation. In addition, you should take care of the thermal insulation between the heater and the handle.

By themselves, all these conditions are easily met in conventional designs that operate at low temperatures. But we talking about a soldering iron- a product, some parts of which are heated up to hundreds of degrees Celsius. The first problem is already in the fact that many materials that could be used in our product immediately disappear. They just can't handle high temperatures. The second problem is the methods of electrical and mechanical connections. Most of the methods of joining parts available at home are unsuitable when working at high temperatures - they are either not applicable to heat-resistant materials, or the resulting joints will, at best, last a short time and collapse. In the past, for example, I could not find a way to connect the heater wire to the electrical cord for a long time. Attempts to directly connect a copper wire to a high-resistance wire constantly ended in copper burnout and the destruction of such a connection. Later, the correct solution was found - an intermediate link made of steel wire ensured high reliability.

3. Materials for making a soldering iron

After the first glance at the photo with the image of the materials, it may seem that the contents of the wastebasket were shaken out and carefully laid out in front of the camera. Yes, the soldering iron described in this article is made from such "garbage".

With the choice of material for the handle did not have to be particularly tricky. soldering iron handle made from wood. It is an easily accessible material, which is easy to process, strong enough, and has good thermal insulation properties.

Tin from a tin can is used for soldering iron body. It is a mild sheet steel that is easy to cut and bend, and at the same time, rolled into a tube has enough miniature soldering iron strength. I strongly recommend tin from condensed milk - it does not have polymer coatings, which is important for our case. Tin, coated on the outside with varnish, like canned fish, or on the inside with something white, like various peas and corn, is not suitable because of this very coating. At a high temperature, it will begin to release combustion products that we do not need. I especially want to emphasize that in the store you need to buy not "condensed milk", but whole milk condensed with sugar. I will not describe the difference here - this is not relevant to the topic, but there is a difference between these products, and the quality of the tin can also be different.

Next on the list we have silicate glue. This is a very interesting substance. It does not contain organics, it is not poisonous, it is not dangerous for the skin - you can work without gloves. After drying, it turns into glass - a substance that easily withstands high temperatures (more than sufficient for a soldering iron) and at the same time does not conduct electricity. When a heat-resistant fiber is added, it forms a composite that also has high mechanical strength. What we need as insulation for heater manufacturing.

Silicate glue in Soviet times could be bought at any bookstore. It was the most popular adhesive for paper and cardboard. But, I must admit, it is not very good for paper. Apparently, therefore, now it is not so easy to meet him on sale. Silicate glue has been almost completely superseded by more modern paper glues. It's a shame, because it's irreplaceable. soldering iron. However, it is still on sale to this day. The bottle of glue shown in the photo among other materials was bought in 2016 for a symbolic price. Rubles for fifteen. I confess, when I saw it in a newsstand located on the territory of a grocery store, I immediately thought of a new one. homemade soldering iron, which will bring together all the accumulated best technological solutions. The seller somehow strangely looked at me, clearly not approving the choice. I wanted to offer a better glue. But I assured her that silicate glue domestic production for some cases is simply irreplaceable. She had nothing to argue against such a powerful argument, and a profitable deal was made.

I will add that there is a lot of Chinese glue for paper on sale now, and, it seems, also silicate. But I did not try to use it, as I very much doubt its composition. Most likely, it contains a large percentage of impurities that make the glue more suitable for paper, but completely unsuitable for manufacturing. high temperature composite. These possible impurities, when heated, can begin to chemically break down with the release of toxic substances. A significant reduction in the strength of the product is also possible. Therefore, for me, when buying, it was important that this is a domestic-made glue, moreover, it is very cheap, which means that it is just liquid glass without any additives.

Thin steel wire is used to tie the tin case, which allows you to fix the heater in it, as well as create a "thread" for the handle - a simple but very effective solution. In addition, two pieces of steel wire are required to make the heater leads.

You will need mild steel sheet with a thickness of about 0.5 mm. A small rectangle is folded into a cylinder, which is then inserted into the body from the side of the handle attachment and provides the necessary strength in this place. Sheet galvanized iron is sold in building materials stores. It is mild steel, like the one used in tin cans. It is also easy to cut and bend, but it is much thicker than canning, and therefore the details from it are stronger. It is not a shortage, but only large sheets are sold in stores. One such sheet is enough for a thousand soldering irons. However, the material is good for many applications. In any case, you need to have it in the household.

For heater manufacturing will also need high resistivity alloy wire. You can get this wire in different ways. In the case described, the wire is taken from a wire-wound trimmer that was once soldered from a domestic-made color TV. To align it, the wire can be pulled over the edge of the table. It is necessary to evaluate the thickness of the wire, its length and resistance. High precision in this case is not required. Just be aware that very thin wire reduces the reliability of the soldering iron due to the risk of burnout. Thick wire will be more difficult to wind, and the thickness of the product will be increased. With the resistance of the wire (and, consequently, with soldering iron supply voltage) it is difficult to guess exactly - it is not known how much it will go to the heater. It is easier to make an approximate version, and when the soldering iron is ready, select the voltage to achieve the required power. But too big errors with the heater resistance will lead to the fact that either a very large current will have to be supplied to the heater, which increases the requirements for wires and electrical connections, or to make a power source with a very "specific" voltage, for example, 50 volts. However, power from 50 In case of an overestimated resistance of the heater, it is much better and more reliable than an unreasonably large current - with an underestimated one.

For making a sting a thick winding wire with a diameter of 1 to 2 mm is excellent. You can set aside a whole coil of such wire as a consumable, and in the future, as it wears out, make new stings. Soldering iron design provides for the possibility tip replacement. It is inserted into the steel base of the heater and held on by friction. So you don't have to worry about burnout.

Asbestos is a natural fibrous mineral. High temperature resistance is one of its most valuable qualities. In conjunction with silicate glue allows you to get an excellent composite for heater insulation.

As you can see, the materials are mostly readily available. Difficulties may arise in finding asbestos. If you can’t find a cord, you can try to grind asbestos cardboard and mix it with silicate glue to get a slurry. And use it to isolate the heater. But I have not tried this method. I used a cord, separating more or less even sections from it and winding it on an insulated surface. Then impregnated with silicate glue. You could try using fiberglass. More on this at the end of the article. There was an idea about using gypsum or even clay, but I did not try to use these materials either, so I can not guarantee anything. One way or another, you can find something suitable.

4. It's a pity not for a bee, or What should be a good sting

If the theater starts with a hanger, then a soldering iron starts with a sting. Both convenience in work and the result obtained largely depend on the quality of the sting. Making a soldering iron it is also wise to start with the choice of stinger. But what is it - good sting?

Here I would like to recommend a small article. It tells about the physical essence of the process, how wetting, capillary effect and surface tension solve most of the problem for us. This information is very useful for beginners, and will not interfere with those who continue.

But, returning to the topic of a good sting, you have to remember physics again. Now from the field of thermodynamics. Don't be afraid - there will be no formulas. It's about the form working surface of the sting. I had to touch on this topic due to the fact that manufacturers of soldering irons somehow peculiarly understand the optimal shape of the working surface and supply their product with tips sharpened under a cone. Suffer from this, as a rule, imported soldering irons. I can't say the same about domestic ones. I think this is such a marketing ploy among foreigners, counting on a mass amateur who has a sharp end conical tip associated with high precision soldering. But let's figure it out. The cone, in principle, is beneficial and effective, but only from the point of view of heat transfer along the entire length of the sting - this is when everything conical sting(at least its outer part). At the same time, the working surface in the form of a cone is extremely inconvenient and inefficient. That is, if you sting cylindrical, and the working end is conical - this is bad and pointless. Why is this so, and what does physics with its thermodynamics have to do with it?

As is known, heat transfer proceeds the faster, the larger the surface area of ​​contact between the interacting bodies. In our case, this is a sting and a detail. So, ideally, the surfaces should either be both flat, or each convexity should have its own "convexity", and vice versa. Conical working surface of the sting thus optimized for soldering "pits" and all sorts of "holes", which is not so in demand in practice. But to work with a plane, for example, irradiate the contact pad on the board, a cone will be much more difficult than a flat face. Practice shows that it is the flat edge that is the most versatile working surface, which means that the sting can be sharpened as you like, but so that there is at least one flat edge. In this case, it is not at all necessary to turn the sting into a "shovel". Even the smallest flat surface at the end of the tip gives a noticeable gain in ease of use of the tool. For thin stings(1-2 mm) we can recommend two classic forms of sharpening: wedge-shaped - with two flat edges, and in the form of an oblique cut - with one flat edge. Of course, any variations are also possible (there are indescribable many of them) for reasons of convenience for a particular case, but do not lose the working edge by getting carried away with sharpening.

We figured out the shape of the working surface. And now it may not even be clear why I find fault with the manufacturers of soldering irons with conically sharpened tips, if the tip can be resharpened. Yes, the fact of the matter is that not every sting provides for sharpening. The ones I've criticized are often short and not made of copper. It seems like this is some supposedly wear-resistant fireproof alloy. Maybe with some kind of coating. There is no point in sharpening also because this alloy is poorly wetted with solder. That is irradiate such a sting is very difficult even with the best fluxes. And after a long effort, when everything seems to have worked out, the tip is tinned, soon the solder on the surface of the tip becomes uneven again, gradually begins to collect in droplets. Maybe that's why the sting doesn't burn, because it can't be used. It's like that joke: so that toys do not break, do not give them to children. Why then use such metal for a sting, if even an ordinary iron nail is more suitable for this role? But maybe I'm just misunderstanding something about newfangled stings. I would be grateful if someone could tell me where I'm wrong, if so.

Nothing better than the most ordinary copper for a sting, I can not advise. Some copper alloys are good too. I'm in my soldering iron I used a piece of thick winding wire for the sting. First the sting was made with some margin in length, then I shortened it slightly. This is due to the fact that for a tip with a constant cross-sectional area (not a cone), there is a maximum allowable length value for a given diameter. Approximately (I do not pretend to be mathematically accurate!) The length of the outer part of the cylindrical tip (from the tip to the edge of the heater) can reach ten diameters. Exceeding this limit reduces the efficiency of the tip in terms of heat transfer, as a result of which, even with a powerful heater, it is still possible to solder only small parts.

And now, when there is complete clarity about what should be good sting, you can describe the process soldering iron manufacturing. In my description, I do not give exact dimensions, since this does not make any sense. Accurate copying of the product in compliance with all dimensions is an extremely time-consuming task. The technology that I propose is based on the fact that the dimensions of subsequent parts depend on the finished ones and are adjusted to the exact dimensions of the finished parts, where necessary. In those cases where the dimensions are not of fundamental importance, they are chosen "by eye". And the first dimensions that I had to decide on were the diameter and length of that part of the sting that is included in heater. I prepared a piece of thick winding wire for the future sting, aligning one end of it. The enamel coating has not yet been removed, so that there is some margin in diameter. There were fears (perhaps unfounded) that I would not be able to insert the sting due to "too precise" size matching. Thus, the diameter of the enameled copper wire became the internal diameter of the base of the future heater. I chose the length of the heater intuitively.

5. Heater base

The base of the heater is made of tin from a can. It is a steel tube, which, with some friction, includes a blank for the sting. The tube is obtained by folding a tin rectangle on a mandrel of suitable diameter. For folding the sheet, you can use a vice and pliers. The dimensions of the rectangle are chosen so that the edges of the metal sheet meet without overlap and do not form a gap. One end of the tube (from the side where the sting enters) expands in the form of a bell. To do this, several cuts are made on the edge of the tin blank before being rolled into a tube. The opposite end of the tube, on the contrary, is jammed so that the inserted the sting had an emphasis on heater. When jamming the end of the tube, do not forget to first insert the blank of the sting, otherwise the tube will be deformed more than necessary, and the sting may not be fully inserted in the future.

If you want to have soldering iron If there was an additional wire connected to the tip, for example, for antistatic purposes, then it makes sense at this stage to insert a piece of steel wire into the jammed end of the heater base to a depth equal to the length of the jammed part of the tube. In the future, you can solder an antistatic wire to this steel wire and connect it to a bracelet on your hand (preferably through a 1 MΩ resistor). Then electronic components sensitive to static electricity will be safe. Grounding is not required for this purpose. But keep in mind that if you connect the antistatic wire to ground and do not connect it to your body, then the effect antistatic protection will not be - the potentials between you and the earth will not be aligned. And remember that you can connect yourself to ground ONLY THROUGH A RESISTOR of at least 1 MΩ. It's without options. The equipment is grounded, of course, directly, without any resistors.

Finished heater base must be covered with a strong heat-resistant insulation. I used for this asbestos cord and silicate glue. He separated small bundles of fibers from the cord, removed defects in the form of solid particles, and wound them on a tin tube as thinly as possible, but without gaps. At the same time, the fibers were impregnated with glue. The blank of the sting was inserted to prevent the glue from flowing into the cavity of the tube. Periodically, I pulled out the sting blank from the tube to prevent it from sticking to the base of the heater.

Before winding high-resistance wire, the insulation layer must dry well.

6. Making the heater

winding process heater wire does not require special comments. The photo shows how it was done. The first layer is wound from the rear end of the heater base towards the tip.

It is desirable to lay the turns closer to each other, but not too close, leaving some distance between them so that the probability of short-circuited turns remains minimal. The wire, of course, tries to unwind, but you need to somehow prevent it from doing so. Various tricks are suitable for this.

The first layer of turns is covered with insulation in the same way as the base of the heater was covered. After that, the glue is dried again.

The second layer of turns is wound in the opposite direction - from the tip to the rear end of the heater. And again, the product is covered with insulation, and then thoroughly dried.

If, after the next drying of the insulating composite, significant irregularities are visible, they can be smoothed out with a file or sandpaper. It is useful to do this at every step, thus maintaining the cylindrical shape of the heater. In this case, care must be taken not to expose the surface to be insulated. It is better to scrape the dried composite in the fresh air so as not to spread asbestos dust in the room - they say it is not very useful.

Direct connection of ends high-resistance wire and electrical cord supply voltage to the heater is not a good technical solution. If this is done near the heater, then the junction will be exposed to high temperatures and will quickly collapse. If this is done inside the handle, where it is cooler, then such a connection, although it will last longer, will also collapse. And besides, even the ends of the high-resistance wire will emit unnecessary heat all the way from the heater to the handle. A reasonable solution is to use an intermediate link made of a metal that tolerates high temperatures well and, at the same time, has a low resistivity. Steel is quite suitable for this role.

For making heater leads I used two pieces of steel wire in my soldering iron. Given the high temperature, soldering here does not make sense. The connection is made by winding one wire onto another. But simple twisting is unreliable. To increase the reliability of the connections, they are crimped with tin tubes, which are made in the same way as the heater base - by folding a tin rectangle on a mandrel. But here it is better that the edges of the tin strip meet with some overlap. As a mandrel, you can use a needle of suitable thickness. With a correctly selected diameter, the finished tube is put on the junction with some friction. Further, each worn tube is compressed by pliers, slightly flattened, which ultimately ensures high strength of the connection.

The next step is to isolate the findings. For this, the same materials were used - asbestos and silicate glue. At this stage, it is necessary to exclude any possibility of shorting the heater leads. This is especially true for joints crimped with tin tubes, since these places are much thicker. Steel heater leads covered with insulating composite up to the point where they connect to the copper conductors electrical cord inside the handle.

Next, the finished heater was thoroughly dried. Dry soldering iron heater you can simply put it somewhere and forget about its existence for a long time, or apply a small voltage to its outputs to speed up drying. In the second case, it should be remembered that too high a voltage can cause the temperature to rise to such a value that the silicate adhesive begins to boil. Until the glue dries completely, you can not bring the temperature to the boiling point, otherwise it will lead to various swelling and deformation of the product, which in the end can ruin the whole work. Irregularities on the surface of the dried heater can be eliminated with a file and sandpaper, bringing the shape of the product to a cylindrical one.

By measuring the resistance between the base of the heater and its terminals, one can to some extent judge the completion of drying. In my case, this resistance after a thorough drying of the heater was 20-30 kOhm. By this time, the danger of boiling glue was no longer there. After warming up the soldering iron in operating mode, this resistance increased to several megaohms.

8. Manufacture of the body and installation of the heater

The body is made of tin from a tin can. The workpiece is a rectangle, the width of which depends on the diameter of the heater. In my case, the dimensions of the workpiece were 20.5 X 80 mm. Rows of holes are made to reduce heat transfer on the body in the handle.

The workpiece is rolled into a tube on a mandrel of suitable diameter. A heater is inserted into the resulting tube.

Heater fixed in the housing by tightly wrapping the housing in the area of ​​the heater with steel wire. In order for the ends of the wire to meet, I first bent it at a right angle, retreating a few centimeters from the beginning, and laid this section of wire in the gap between the edges of the body plate bent into a tube in the direction from the future handle to the sting. Then he tightly wound the wire coil to coil in the direction from the tip to the handle and connected the ends with a twist. I tucked the twist into the slot of the case.

9. Design features on the side of the handle

The opposite side of the housing, connected to the handle, is reinforced in the same way as the side of the heater - by wrapping it with steel wire. At the same time, this winding also plays the role of a thread, which provides the possibility of simple and high-quality body-to-handle connections. Of course, I did not cut the thread in the hole of the handle, but only adjusted the diameter of the hole with a round file to the size when the wire "thread" without excessive effort, but at the same time firmly screwed into the handle.

The wire is wound as tightly as possible to make the case durable. But if a stone-hard heater is located on the side of the sting under a thin tin, then the side of the handle would have been crumpled during the wrapping process if I had not installed an additional part - a reinforcing sleeve. The sleeve (see photo) is made by bending a rectangle cut from a steel sheet (galvanized iron).

Inside soldering iron handles the temperature is no longer as high as near the heater, so the choice of materials and methods for connecting parts is much wider here. Less heat-resistant materials can be used, and electrical connections can be made by soldering. To connect heater leads With electric cord it turned out to be tough, I inserted a fiberglass rectangle into the body of the future soldering iron between the leads sticking out of it. The width of the rectangle is chosen so that it is inserted with considerable effort and does not dangle after installation.

10. Making a handle

soldering iron handle planed with a knife from a wooden block without the use of machines. But first, a hole was drilled in the bar. If you first plan out the cylinder, and then drill a hole in it, then without using a machine it will be very difficult to get a hole exactly in the center. It is much easier to first drill and then evenly plan the workpiece around the existing hole. The finished handle is processed with sandpaper.

The diameter of the hole in the handle on the side of the connection with the body is slightly increased by a certain depth. This is done so that the actual contact of the metal case (carrying the unwanted heat flux from the heater) with the handle is a little deeper inside the handle. Thus, while maintaining a small distance from tip to handle decreases handle heating.

As electrical cord I used a cord from a handset. I agree that this is not the best option for a soldering iron - such a wire is designed for currents of a maximum of several tens of milliamps, which for soldering iron not enough. To burn something will not burn - it will create unnecessary resistance. But I wanted to have a cord twisted into a "spring". Yes, besides, a wire turned up, which had a defect in one of the connectors, and it was no longer suitable for its intended purpose. The photo shows how the connection is made. The ends of the conductors of the cord are free from insulation. The cord is fixed by winding it with threads to the fiberglass protruding from the body. The place of fastening with threads is covered with BF glue (in the photo it is marked with the number 2). The connection of the heater leads with the copper wires of the cord is made by soldering (in the photo it is marked with the numbers 1).

12. Finishing the assembly of the soldering iron

Of course, before attaching the cord, I put a handle on it. Then all that was left to do was turn soldering iron body into the handle with the help of his improvised carving.

After connection of the handle to the body the place of the cord exit from the handle is additionally reinforced so that the cord does not hang out in the handle and extraneous forces are not transmitted to the connections inside.

Finally, sting inserted, soldering iron tested. Everything worked out as it should. Properly assembled from suitable materials, the soldering iron does not smoke or exude odors. I later varnished the handle.

If a the stinger enters the heater too loose, you can wrap it with a strip of aluminum foil. It is better not to use copper foil, so as not to get scale in its place over time, which makes it difficult to remove the worn sting. After testing, I shortened the sting a little, bringing its outer length to about ten diameters. Reducing the length of the tip expands the capabilities of the soldering iron and even allows thin sting do the smallest work.

13. To be continued?

After the soldering iron was ready, ideas began to appear to improve the technology. In the store, I somehow drew attention to fiberglass. Bought a small piece. Fiberglass threads are easily separated from the flap at the edge. The idea was to use fiberglass instead of asbestos. This will be much easier already for the reason that artificial glass threads have practically no defects, unlike natural asbestos, which is full of small knots and solid particles. But haven't tried it yet. I don't know if it's possible to get a good composite if both the fiber and the binder are almost the same. In this case, both are glass. However, they are different types of glass. I think for soldering iron this combination should work just fine. Who will try before me, tell me what happened.

In addition, the idea arose to apply bifilar wound wire heater. To do this, the wire is folded in half, and then wound on the base of the heater from the tip to the opposite side so that the turns do not intersect, and the middle (place of bend) of the wire is at the very beginning of such a winding - from the side of the tip. In this case, there will be only one layer of wire, which will significantly reduce the diameter of the heater, and hence the entire soldering iron will become thinner and more elegant. Have you seen how a glass tube is twisted in energy-saving fluorescent lamps? There, the spiral is single-layered, but both ends of the tube meet on one side of this spiral. The difficulty is only in the higher requirements for inter-turn insulation. In the method that I used in my soldering iron, the turn-to-turn circuit is not significant. The soldering iron does not lose its working capacity from such a short circuit (unless there are too many short circuits). And in the case of bifilar spiral circuit can completely withdraw soldering iron out of service. To prevent this from happening, you can try one of two options. The first option involves covering heater wire before winding it thin but strong heat-resistant insulation. This can be tried by wrapping fiberglass around a wire and impregnating it with silicate glue. The second option is to fill the gaps between the turns of the already wound wire with the same glue-impregnated fiberglass. I like the first option more, since the spiral should be tighter and neater. But you have to try.

At the beginning of the article, I promised to talk about the manufacture of a reliable soldering iron that is not inferior to the factory one. After reading the article, I think you noticed that all the connections are not made "bluff". Despite their technological simplicity, they provide (in the absence of defects in work) a sufficiently high mechanical strength the whole structure and reliability of electrical contacts. This means that once you spend time on soldering iron manufacturing, you can get a tool that will faithfully last more than one year. Or maybe the grandson will not be ashamed to give.

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