Restoration of threads for heating the rear window. Shamanic methods. Rear window heating restoration DIY rear window heating repair
You will need
- - voltmeter;
- - low-tin solder and zinc chloride;
- - graphite powder, iron filings, nitro varnish, epoxy;
- - silver sawdust and nitro-glue;
- - copper sulfate solution, cloth, long copper wire;
- - electrically conductive adhesive
Instructions
Find damage in the heating filaments using a voltmeter. To do this, connect one contact of the device to the busbar, and smoothly drive the other along the idle strip. Another method of finding a broken thread: turn on the heating on the fogged glass. In this case, all the glass will quickly sweat except for the place of damage. This method is simpler than the previous one, but it is not accurate and does not always work.
Regardless of the chosen repair method, first clean the damaged area from the varnish until a metallic sheen appears. It is more convenient to do this with a bent wire. Degrease in any way. Having soldering skills, solder the damaged area with soft low-tin solder such as POS-18 or POSS-4-6. Use zinc chloride as a flux. If there is damage over a long stretch, solder a thin copper or silver strand from a suitable piece of wire.
To repair using another method, coat the damaged area with a mixture of graphite powder and a small amount of epoxy glue (resin). To make the work better, install a strong magnet on the back of the glass, and put small metal filings in place of the area to be restored. They will restore the contact of the threads. After repair, treat the damaged area with nitro varnish. Remove the magnet after the varnish is completely dry. When applying sawdust, try to hit the conductor strip as accurately as possible, and not the entire surface opposite the magnet. This will help make the repair site invisible.
For the third method, take silver filings. Prepare them by grinding off the alloy of unnecessary contact with a file power relay... Pour sawdust into the fold of a sheet of paper and add a drop of nitro glue. With the end of a knife, quickly roll out cylinders 1 mm in diameter and 2-3 mm in length from sawdust. Apply it to the damaged area and crush, pressing firmly on the sawdust. Remove excess.
Another method is perfect for restoring a damaged area or the entire heating thread. Prepare a solution of copper sulfate, consisting of 6 parts of water, two parts of powdered sulfate and one part of electrolyte for the battery. Mix thoroughly. Take a thick, long copper wire from the positive terminal of the battery to the glass with threads. Wrap a piece of fabric 1-2 cm wide and 10-15 cm long around the end of the wire and secure in any way.
With the other end of the wire connected to the positive terminal of the battery, soak the wound cloth in the prepared solution. Start rubbing vigorously at the break for 1–2 minutes. This will start to deposit copper around the intact filament. Copper will look like patterns on frosty glass. When restoring the entire thread, start from the place where it is connected to the side live parts. This method is cheap, affordable, and has a high durability of the restored area. On the other hand, it is quite long-lasting.
For a more modern restoration method, purchase a special electrically conductive adhesive. When buying, consult with the seller. Use the stencil supplied with the product to restore the filament. Apply glue to the damaged area with a soft brush through a stencil and dry for 10-15 minutes.
Hello to all!I have a problem with the heater rear window when I cleaned the tape with which the Transit was glued damaged the heating threads ...
Several of the threads did not warm up.
For repair we need:
1. scotch tape, better narrow;
2. scissors to cut the tape;
3. Composition for repairing heating threads by Done Deal DD6590;
4. Voltmeter, in my case a multimeter;
5. Glass cleaner such as mister muscle or alcohol.TROUBLESHOOTING
To begin with, we simply visually inspect the threads for breaks, cuts, etc. they are clearly visible on them.
Then we turn on the heating of the rear window and wait, 1-3 minutes, the glass will gradually heat up, then I just touched which of the threads do not heat up, and we will test them with a voltmeter.
1 of the voltmeter probes (minus) we hook to ground, in my case it is the rear door shock absorber mounting bolt.
Then we begin to measure the voltages by pressing the positive probe of the voltmeter to the heating threads, which we have not heated up ... Usually, at the break point, the voltmeter sharply shows ZERO, i.e. for example, first 10 volts, and a little move and immediately zero. a gap is found ... if you continue to move the probe, the voltage should reappear, then the gap ended. I only had an almost invisible break on 2 threads, i.e. the thread itself is intact, but "remove" the top layer from it, i.e. the thread became thinner and stopped working and visually it is a little visible, tk. its color in this area was different from the rest of the length.GLUE
0. With a glass cleaner we wash the areas where we will apply the composition.
1. Cut off a certain piece of scotch tape and glue the top and bottom of the thread opposite the break so that the scotch tape goes about 0.5-1 cm on the sides of the break ...
2. When all the places of the gap have been sealed in this way, we begin to dilute the composition, I used an inverted tin can from Sprat in tomato sauce, THIS IS A MANDATORY CONDITION! :)))
3. Carefully moving the composition, apply it with a thin layer on the thread ... better less than a layer of 2 mm :) I applied with a piece of a wooden stick that came in the kit ... the composition is quite liquid and either a brush or a cotton swab for the ears is best suited :) now I figured it out ... so you better use this option!
4. When we missed everything, turn on the heating ... and WE WILL WORK THAT EVERYTHING EARNED ... though the threads that are being repaired are heated a little weaker ... this gives an advantage in the speed of drying of the composition ... about 30 minutes ... finally dries up after a day like ...
5. After 15-20 minutes we begin to tear off the scotch tape neatly, it is better when the composition has not dried to the end, then the repair line remains thin and the scotch tape with the composition along the edges easily leaves. Where the composition was applied with a thick layer of scotch, it did not "break" but crawled out from under it: (((I had to cut a little with a scalpel, but THAT LAYER IS BAD !!!)That's the whole repair. As a result, we have a working rear window heater, the places of repair are noticeable, but I personally do not care, my tinting is native and I don't really look there.
The heated rear window of a car often fails. In most cases, it does not fail completely, but in fragments: individual zones or heating threads do not work. In this case, replacing the glass is completely irrational.
Exists different ways self repair threads and other elements of heating the rear window of the car in order to restore their performance. Let's consider them in this article.
Principle of operation
Heating of the rear window of the car occurs due to the heating of special threads applied to the glass when flowing through them direct current... The threads are made of low resistance conductive material. The total current for the rear window defroster is approximately 10 amperes. The number of threads is about ten. Thus, a current of approximately 1 Ampere flows through each strand. It is easy to calculate according to Ohm's law that the resistance of the filament is about 12 ohms.
Heater filaments are applied when technological process the manufacture of rear glass at the factory in several ways:
- electrochemical;
- vacuum deposition (the most reliable method);
- gluing.
The chemical composition of such threads can include various elements, alloys and composite materials: resins, copper, graphite, nickel, chromium, tungsten. The manufacturer does not declare the production technology, therefore, for each technology (heated glass), it is necessary to select the appropriate method of restoring operability.
For example, brazing is practically impossible if the filaments have been vacuum-sprayed with a carbon compound. In this case, only conductive adhesives are effective.
Connection diagram
Usually, voltage is applied to the heating threads of the rear window battery through the fuse, switch and relay systems as shown below.
In some car models, the rear window heating can only be connected when the engine is running. For this, another blocking relay is provided. The fuse installed on the heater supply is usually more than 15 Amps.
Malfunction symptoms
The main signs of a malfunctioning rear window heating:
- does not turn on completely;
- turns on, but not all threads work (the most common case);
- works periodically.
Why the rear window heating does not work: reasons, how to check, finding the place of failure
If the rear window heating stops working or it works, but intermittently, then this may be due to the following reasons:
1. Malfunction of electrical equipment of the car.
The search for the place of failure should begin with the fuse that serves the heater. If it is working properly, then check the switch (button) of the heater, relay, wiring to the heater contacts.
The heated rear window switch button is checked with a multimeter. Its contacts often burn out as a result of the flow of a large current. In this case, it must be changed.
One of the most likely places for electrical equipment malfunction is a breakdown (or decay) of the attachment point of the contact terminal to the heater. In this case, repair is difficult. It is required to solder using special solders and flux. Bonding with conductive paste is also possible.
Often the electrical wiring is damaged at the transition point of the corrugation, where the wiring from the body to the tailgate is located. It is required to open the corrugation, extract the wiring, search for the broken conductor and eliminate the breakage.
2. Broken filaments.
Such a malfunction may be associated with the removal of the sunscreen film, mechanical scratches on the glass, and natural wear and tear.
Video - how to check the heated rear window with a multimeter:
To search for a specific place where the thread is broken, if it is invisible to the eye, you must use a multimeter. Its probes should be sharpened or connected to sewing needles. This is necessary to ensure reliable contact of the probes with the heater filaments. First, the faulty thread (s) is identified by a visual or tactile (touch) method. It does not heat up. Then the resistance is measured at the extreme sections of the thread.
After determining the location of the damage to the thread, it must be marked with a marker.
How to fix a heated rear window with your own hands
To repair the heated rear window, you should purchase a special conductive adhesive or ready-made heater repair kits. It is necessary to carefully familiarize yourself with the repair technology, which should be described on the packaging or the attached instructions in Russian. Success renovation works is determined by strict adherence to the technology specified in the instructions.
Video - DIY repair of rear window heating threads:
Overview of kits and glue for repairing threads and contacts for heated rear window
Permatex PX 09117 set
The set includes:
- glue for threads 1.4 ml;
- contact glue 0.8 mm;
- a brush for applying glue;
- sample;
- sandpaper;
- activator napkin;
- alcohol wipe.
Mode of application when repairing contacts:
- clean and degrease surfaces;
- clean contacts;
- wipe the surface with activator, wait 5 minutes;
- apply a small (!!!) drop of glue so that it does not protrude beyond the glued surfaces;
- press the contacts;
- give a day to dry.
Mode of application when repairing threads:
- degrease the surface on which the thread will be applied;
- attach a template;
- wait 20 minutes;
- repeat the application 3-4 times at intervals of 20 minutes;
- switch on the heater after 24 hours.
The cost of such a set is about 1000 rubles.
Glue AVS A78358S
Such a conductive glue for repairing rear window heating threads 2 ml costs about 200 rubles.
Conductive adhesive for repairing heated rear window threads.
The price of the glue is about 400 rubles.
Video - how to glue the rear window heating contacts without removing the glass:
The repair technology is approximately the same for all industrial adhesives. The main thing is to degrease the surfaces well and not to rush. If you can't find special formulations for repair, you can try to make them yourself or use other recovery methods.
Self-production of conductive glue, soldering with special fluxes, electrolytic coating
1. Self-production of conductive composition.
The widespread glue BF-2 or BF-6 is often chosen as a base. Other quick-drying adhesives can be used. There are options for using polymer resin, paint, enamel. In order to make a conductive paste from these materials, it is necessary to add fine shavings to it in a ratio of 1 to 1. The shavings can be “mined” with a fine file or file and copper, aluminum or brass material. After mixing the components, they are applied to the prepared surface through a homemade stencil. It is not difficult to make it using construction tape or electrical tape.
The effectiveness of such a homemade composition will be no worse than the purchased one.
2. Soldering the point of breaking the thread and disconnecting the terminal.
Soldering of the thread break is impossible if the distance between the ends of the thread is more than two millimeters. In this case, you can first use the electrochemical method. When restoring the contacts of the connection of the heater terminals, the soldering is more efficient and reliable. Soldering is performed using the classical method using active flux and solder. The solder should be POS-18 or similar. It is better to use a flux of the FCA type based on zinc chloride.
3. Electrolytic coating.
To carry out such a coating, a solution of copper sulfate is required (the proportion is 100 milliliters of water, two teaspoons of copper sulfate, you can add a few drops of battery electrolyte), rags, thread, stranded copper wire with a cross section of 6 sq. Mm (for making a prototype of a copper brush).
Next, a copper brush from a stripped conductor wrapped in rags and thread is connected with the opposite end of the wire to the +12 Volt power source (battery), minus the battery is connected to the body or directly to the heater terminal. The brush is moistened with a homemade electrolyte. After that, a moistened brush is vigorously driven in the place of the rupture of the filament. The treatment site is gradually covered by copper particles as a result of the electrolysis process.
Good afternoon. Today we will talk about how to repair a heated rear window. Traditionally for our site, the article contains a lot of photos and videos and is a step-by-step troubleshooting algorithm.
How does glass heating work?
I think everyone remembers the physics from the high school course. When an electric current flows through a conductor, it heats up. It is on this principle that the rear window heating works.
If you look closely at the glass, you will see contacts and current supply wires from the sides.
When a voltage is applied to these terminals, an electric current flows through the heating filaments and heats the glass, thereby making it.
Accordingly, glass heating does not work in only two cases:
- heating threads are faulty
- no voltage at the terminals
How to repair the heating if one or more heating threads are faulty?
This malfunction looks like this:
For repairs we need:
- sandpaper with a number from 1500 to 2500, 1 sheet of any grain. It is needed to remove oxides and varnish from places of damage to the threads.
- alcohol, preferably isopropyl (we will use it to wipe the glass from dust and degrease the damage)
- napkins, microfiber, cotton swabs or rags (for cleaning).
- conductive adhesive, in stores it is not always available, so if you are ready to wait, I recommend ordering it directly from China (we will use it to restore damaged threads).
Repair procedure:
We carefully examine the faulty heating threads and look for damage, they usually look like this:
We carefully clean the damaged areas with emery paper, trying not to touch the glass, we only clean the heating threads themselves and then next to the damage. If you rub the glass itself with sandpaper, it will become dull, but it will not come out, since the heating threads are not applied to it.
Wipe cleaned surfaces with alcohol using a cotton swab. In this case, we will remove the dust from the sandpaper and degrease the surface.
Gently apply conductive glue to the damaged areas. In order to apply the glue directly and not as a stain, it is better to use duct tape or masking tape. As shown in the video at the end of the article.
Apply conductive glue with a brush.
We wait until the glue dries, check it, make sure that everything works and enjoy the money saved….
What if the heating does not work at all?
If the heating does not work at all, there are two options. Either all the heating threads are faulty (this is unlikely, even on machines that are 30-40 years old, one or two threads heat) ... Or the wiring is faulty.
A person without special education can only check 3 things:
The location of these items can be found in the operating instructions for your vehicle.
If, after checking, by the replacement method, your heating still does not work, it is better to contact an electrician at the station of those. service.
How to repair the heating if the glass is tinted?
I don’t want to upset you, but most likely the answer is no! Since to apply electrically conductive glue, you will have to locally (locally) remove the tint anyway. I'm not sure if you can cut a piece of tinting with just a damaged thread. In any case, you will get an ugly hole in the toning….
Therefore, if you need to repair one or several heating filaments on tinted glass, unfortunately, the tint will have to be removed.
Conclusion.
As you can see, the repair of glass heating is not difficult, of course, with due care and desire.
Obviously, the easiest option is not to repair the threads, but to replace the glass, but think about how, because if the buyer sees glass from different years of production, then at least they will tell you that the car was a bit.
That's all for me today. I hope that you are not left with any questions about how to repair the heated rear window. If you have any questions, or if you want to supplement the article, write comments.
Good visibility is essential for safe operation car. In the autumn-winter period, the glass fogs up due to changes in air temperature, and visibility through them deteriorates. The issue of glass transparency is especially relevant at night, when visibility is already poor.
An effective way to combat fogging car glass is their heating. Windshield, as a rule, it is heated by directed streams of warm air. The rear window and rearview mirrors are usually heated using electricity. Conductive paths made of high-resistance metal in the form of thin ribbons are applied to the glass surface from the side of the car interior. When an electric current passes through them, thermal energy is released. The glass heats up and the water evaporates. After a few minutes, the glass becomes transparent.
Heater wiring diagram
To successfully diagnose and repair the rear window heating system of a car at a professional level, it is necessary to know the wiring diagram of the heater and to understand the principle of its operation.
The photo shows typical scheme connecting the rear window heater of the car to the on-board wiring. Let's consider how it works.
The supply voltage from the positive terminal of the battery through the ignition switch, and the fuses are supplied to the heater switch and to the 30 (or 87) power contact of the relay. The negative terminal of the battery is connected to the car body, one of the terminals of the glass heater is also connected to the body. When you press the heater power button, voltage is applied to the relay coil, the relay is triggered, the power contacts close and connect the relay terminals 30 and 87 to each other. The current enters the heater, flows through a group of parallel-connected threads and returns through the car body to the negative terminal of the battery.
Rear window defogger malfunctions
The functionality of the rear window defroster is ignored until the glass fogs up or becomes covered with frost. After turning on the heater, it is suddenly discovered that after a few minutes the glass did not become transparent or that visibility appeared only through a part of the glass. Depending on the external manifestation, even without measuring instruments, one can immediately make an assumption about the cause of the failure.
It should be noted that the rear window and rear-view mirrors heater can only be switched on when the ignition key is set to the ON position. In some car models, the heater can only be turned on when the engine is running. This is done to avoid a strong discharge of the battery, since the rear window heater, depending on the car model, consumes a current of 10 A to 25 A. For comparison, one car headlight consumes a current of only 5 A.
The heater does not turn on
If the indicator on the button for turning on the rear window heating does not light up after pressing it, then the fuse is most likely blown or the key itself is faulty. If the indicator is on, but not a single thread heats up, then the cause of the malfunction may be a relay or connectors for connecting the heater to the wiring. In this case, according to the documentation for a specific car model, it is necessary to determine the location of these parts and replace the failed one. It is not always possible to quickly find the place of installation of the relay, but there is a way to check its serviceability in an indirect way, which will be discussed below.
Glass is slowly sweating
Sometimes there is a case when, after turning on the heater, the glass sweats for a time significantly exceeding a few minutes. In this case, if it is not very cold outside, the reason may lie in the poor contact of one of the connectors. electrical circuit... As a result, the contact resistance increases, the current is limited, and as a result, the power released on the glass heater filaments decreases. To check such a malfunction, you need a DC voltmeter (multimeter or pointer tester, included in the measurement mode constant voltage) measure the voltage at the input terminals of the heater and battery. Voltages should not differ by more than one volt.
Horizontal misting stripes remain on the glass
And finally, the most common case of a malfunction of the rear window heating system of a car, breakage of one or more threads of the heater applied directly to the glass. This type of malfunction is immediately visible on the horizontal strip of the remaining fogging on the glass after turning on the heater.
The conductive tracks on the rear window have low mechanical strength and are easily destroyed when exposed to them. Therefore, it is forbidden to remove frost and ice from the glass with a scraper. Only wipe with a soft cloth. It is also necessary to ensure that when transporting bulky items, they do not rest against the rear window. As a rule, individual heater filaments stop working as a result of their accidental mechanical destruction. After turning on the heating, stripes of fog or frost remain in the area of the damaged thread.
When renovating an apartment, I was transporting floor skirting boards in my car and did not notice how one of them rested against the rear window. After a while, when it was necessary to warm up the rear window, I saw the result of my inattention. Two strips of the heater passing through the middle of the glass did not heat up, which significantly impaired the view of the road. Upon visual inspection, on the non-working strips, one gap of about 1 mm wide was found, as in the photograph. The question arose about the need to repair the rear window heater.
How to find a broken glass heating thread
It is not difficult to determine which thread of the heater in the cliff, since in the zone of its passage the fogging does not disappear during the operation of the heater. Therefore, in order to easily find a faulty thread during repairs, it is advisable to count the threads from top to bottom and remember which one is in the cliff by number, so that later visual inspection try to find the place of its damage. But the thread break is so small that it is impossible to find it visually. Then a DC voltmeter, ohmmeter or voltage indicator will help in the search. To quickly find the place of a malfunction in a heating element, you need to imagine how it works and works.
The device of the heating element of the glass heating system
The question is logical, why does it happen that only one or several threads in the heater do not work, and the rest work? To get an answer to this question, you need to familiarize yourself with the design of the heating element.
The heating element of the rear window of the car is arranged as follows. On the lateral sides of the rear window, two conductive buses 1 and 2 are applied. To these buses, threads of high-resistance material are connected. Each of the strands has a resistance of about 10 ohms. The number of threads depends on the height of the glass. Thus, each thread is a separate heating element, the operation of which does not depend on others. The scheme of parallel connection of heating elements is applied. Such a circuit design ensures high operational reliability of the heater, since the breakage of one or several threads does not lead to a complete cessation of its operation.
Finding a broken filament heater using a voltmeter
For work, you will need any DC voltmeter with a measurement limit of 15 V. As a voltmeter, any dial tester or digital multimeter is suitable. Before starting work, you need to turn on the heater.
Since one of the tires of the heating element is connected to the car body, the negative terminal of the voltmeter can be connected to the car body; any screw or bolt screwed directly into the body will do. It is most convenient to attach the alligator clip to the boot lid lock bracket.
Since visually with a transparent glass it is difficult to find out whether the heater heats up, then by touching the positive probe of the voltmeter to bus 1, and then to bus 2, you will immediately understand this. Bus 1 should have +12 V, and bus 2 should have 0 V. It is possible that the left bus in your car will be connected to ground, and the right bus will be supplied with supply voltage. If there is no access to the tires, then measurements can be taken by touching any of the threads with a probe at the points of connection with the tires, that is, in the places where they exit from the rubber seal. In the photo, these are points 1 and 5.
Using a voltmeter, it is easy to determine which part of the heating system is faulty. If the heater is on, the on indicator on the button is on and there is 12 V on bus 1, but there is no heating, then the wiring to bus 1 is working properly. If there is no voltage on bus 1, then there is a bad contact in the supply voltage supply terminal on bus 1, or the relay is faulty. If 12 V is present not only on bus 1, but also on bus 2, then you need to look for a bad contact in the terminal for connecting the wire to bus 2 or in the circuit for connecting the wire to the vehicle ground.
Finding the location of the thread break
After checking the power supply system to the heater, you can begin to determine the location of the breakage of the heating thread. The filament is a tape resistance of about 10 ohms, and therefore the magnitude of the voltage at its different points has a different magnitude. Therefore, at point 1, the voltage will be 12 V, at point 3 - 6 V, and at point 5 - 0 V. Therefore, even without knowing which of the threads is in the cliff, it can be easily found by measuring the voltage value in the middle of the length of all threads. On the broken threads, the voltage will be 12 or 0 V. If the voltage is 12 V, then the break point is on the left, and if 0 V, then on the right.
Now it is enough to slowly hold the probe towards the break, in the place of a sharp change in voltage and there will be a gap. For example, in the photo this is a section of a thread between 6 and 7 points.
Finding the broken thread with an ohmmeter
Using a multimeter or pointer tester in the "title =" mode (! LANG: How to measure resistance">измерения сопротивления тоже успешно можно найти место обрыва нити. Включать обогреватель при поиске омметром не нужно, но проверить исправность системы подачи питающего напряжения на нагреватель, кроме проверки цепи подключения к массе, не получится.!}
If the broken thread is not known, then you need to connect one end of the ohmmeter probe to the ground terminal, and with the second, in turn, touch the middle of the heater threads. The thread on which the ohmmeter will show the resistance is twice as much and will be in a cliff. For reference, the resistance on whole strands relative to bus 1 or 2 should be 2-3 ohms. In the event of a break in the thread, the ohmmeter will show 4-6 ohms.
When the damaged thread is found, it is necessary to move the end of the probe from the center to any side. If the resistance increases when the probe moves towards tire 1, then the break is in the gap between tire 1 and the touch point of the probe. For example, in the place indicated by points 1 and 2. As soon as the probe passes the break, the resistance will sharply decrease several times. If the resistance decreases, it means that the thread breakage is between the probe and the bus 2. For example, in the place indicated by points 3 and 4. Then you need to move the probe towards the bus 2, and when the resistance drops sharply, at this point there will be a break ...
Finding the location of the thread break
with Automotive Probe Tester
If a voltmeter or ohmmeter is not available, then you can find the place where the filament of the heating element is broken using a home-made automotive tester-probe, consisting of just any one LED and a current-limiting resistor. I have made such a tester for myself a long time ago, although I have any measuring devices at my disposal. A homemade automotive tester is always in the glove compartment of my car and I had to use it more than once.
Finding a broken thread with a probe tester is not much different from searching with a voltmeter. The indicator in this case will be not an arrow or numbers, but the glow of the LED.
Before starting the search for a damaged filament with a probe, it is necessary to apply a supply voltage to the heater. First, the presence of voltage on bus 1 is checked, the LED should be on, if the LED is off, then the fault lies in the supply voltage supply circuit. Next, the voltage on bus 2 is checked, the LED should not light up, if it is on, it means that there is a contact failure at the point where the wire is connected to the bus or the car body.
To find the place where the heater filament breaks, you need to slowly, lightly touching the filament, lead along it with the end of the probe. At the point at which the LED turns off or lights up and there is a thread break. For example, at point 6, the tester's LED will glow, and at point 7, it will not. In my case, the thread breaks were large and the tester was only useful for checking the quality of the repair.
Methods for repairing heating element filaments
There are several ways to restore the working capacity of the heating thread at home.
Using conductive pastes and adhesives
The simplest and most effective is with the help of special repair kits, for example, DONE DEAL DD6590, designed to repair the threads and contacts of the rear window defroster by both amateurs and professionals. The method is good in that it does not require tools and materials. It is enough to apply a little conductive paste according to the attached instructions to the place where the thread breaks from the syringe, wait until the paste hardens and the repair is completed. But such a set costs more than $ 15.
The second method is similar to the previous one. But instead of a proprietary set, purchased conductive adhesives are used, for example, "Elekont", a Moscow manufacturer. The glue is applied to the place where the thread breaks, overlapping the whole part of the thread by a centimeter on each side. To get a neat look, a stencil made of electrical tape or scotch tape is used. For reliability, the glue is applied two times. Between the layers of conductive glue, it is advisable to lay a piece of tinned copper wire with a diameter of 0.3-0.5 mm.
It is believed that a conductive paste or glue for repairing glass heater threads can be made independently by mixing paint or glue with brass sawdust in a one-to-one ratio. The resulting composition is applied through a stencil in a thin layer to the thread breakage in several layers. But the reliability of this technology has not been confirmed by practice.
Electroplating copper
Another method is the electroplating of copper. The heater filament repair method seems attractive. But from my personal experience, I can say that the reliability of such coatings at home is low. So I hesitated to use this technology.
By soft soldering
The mechanical method of restoring the integrity of the rear window heater filaments by soft soldering has become widespread. The reliability of this method was tested by me when repairing rear window heating filaments in my own car. Given below step-by-step instruction, written on the basis of my experience, will allow you to easily repair the heater thread on your own in just a few minutes with practically no financial costs.
On the advice of theorists from the Internet, I made a big mistake, tried to strip the thread with sandpaper. As a result, instead of breaking a thread with a width of 1 mm, a break of more than 1 cm turned out. The thread tape is very thin, with only a couple of tens of microns and is erased, even with the finest-grained sandpaper, instantly. The heater threads are not covered with anything anyway, and it is enough to degrease the soldering area with a rag dipped in alcohol or acetone.
If the width of the thread break is less than 1 mm, then you can do without soldering the additional conductor. In my case, the width of the gap was large, and I had to pre-prepare a piece of copper wire for the jumper. A current of about 1 A flows through one thread of the heater. Based on this, we select a wire with a cross-section of 0.17 mm 2 from the table of wire cross-sections, which corresponds to a diameter of 0.45 mm. The length of the copper jumper should be equal to the width of the thread break plus 2 cm. Before soldering, the jumper must be tinned with a thick layer of POS-61 tin-lead solder. There is no need to tin the heater thread.
In order for the solder to reliably adhere to the heater thread, before soldering the jumper, grease the thread in the soldering area with a brush with a thin layer of zinc chloride flux.
Next, the jumper is pressed against the heating thread and heats up for one second with a 12 W soldering iron. The hand is pulled to the side. The jumper should be kept on the string. Trying to pull it to check the quality of the soldering is unacceptable, it will fall off, and also tear off a piece of the heater thread. Unfortunately, it has been tested empirically. As a result of experiments, I ended up having to solder the jumper 5 cm long.
After soldering one end of the jumper, the other is pressed tightly to the thread and also warmed up with a soldering iron. After the end of soldering, in order to remove the acidic flux residues, the glass is thoroughly washed with water.
To top it off, for reliability, although it is not necessary, I covered the soldered jumper on top with a transparent superglue "Moment" based on cyanoacrylates, the heat resistance of which is about 70 ° C. The heater does not heat up above this temperature.
As a result, the time to repair a thread break with your own hands, taking into account all the preparatory work, was no more than ten minutes. The repaired threads have been in service for over three years.