Working Principle
Thermofens can be divided into two groups: professional, they are industrial, and domestic, which are used by home masters.
Secondary soldering is an opportunity to make repairs with your own hands in an apartment or private house, to repair the bumper of a car or a part of a scooter. The air temperature of a household plastic brazing dryer reaches 550 ℃.
Soldering plastic is often referred to as welding, because the melting of the material of the parts and its connection at the molecular level takes place.
Household appliances are also divided into two groups: with a manual method of adjusting the temperature of soldering and automatic. In the first case, the temperature at the hair dryer is set manually.
But there is one subtle point. the distance from the nozzle heaters to the soldered plastic maintained by the master himself. Therefore, the insufficient distance can lead to failure to weld, and this will cause a decrease in the strength of the connection.
This is because the greater the distance, the faster the temperature in the welding area decreases. For example, it is believed that removing the nozzle of the hair dryer from the welding zone by 8 cm reduces the temperature of heated air by half. If the mode was set to 500 ℃, it reaches the plastic workpieces to be welded at 250 ℃.
NEVER DISSOLVE plastic canisters! Great idea with your own hands!
The automatic model with a sensor differs from the manual model in that the heating temperature is adjusted as the tool nozzle gets closer or farther away from the soldering zone.
For all other indicators and characteristics, it is the same devices, consisting of a housing, a heating element and a fan, with the help of which the air supply is created. It is very important to pay attention to the capacity of the heater. Construction hair dryer has a power of at least 1.6 kW.
Making a heat gun
A fan-assisted hair dryer and a 0.4 mm thick nichrome coil are well suited for making a heat-soldering iron by yourself. As the assembling of self-made device is supposed to be compact in size, the spiral diameter is greater than 0.5 mm will not do. For a larger cross section will need a higher current. First you need to select the power source, and then choose the number of turns, as this will depend on the resistance of the coil and the heating of air. To assemble a powerful heat gun, it is enough to have a power source with a voltage of up to 36 V.
Housing and heating system
As the body of the heat gun can be used an old soldering iron or a steel tube, but since the operating temperature will be high, you need to wrap the tube heat-resistant material or attach a handle-holder. Also a car cigarette lighter can be used as an air duct, inside of which the heating system will be placed.
The next step is to wind the nichrome spiral with a small distance between the coils. A ceramic tube with a diameter of 4-5 mm can be used as an insulator, on which the coil is wound. The length of the coil must be wound taking into account the resistance, which is calculated in the range from 70 to 90 ohms.
The end of the tube can be equipped with a ceramic or faora tubular element, and the spiral is better to wind it on a flat plate, which will favorably affect the heat transfer. Diverters in the form of petals, which will not touch the insulator. To increase efficiency, you can make thermal protection with fiberglass or asbestos.
Air supply device
To supply air, you can use a small-sized cooler from a computer power supply, which is installed near the handle of the heat gun. A metal tube with a wound coil is connected to the fan.
At the end of the fan a hole is cut out for the air flow to the tube. One side of the cooler is hermetically sealed. Mica plates from an old hair dryer can be used as the base of the thermal system. A cross-shaped base is made of such plates, and a nichrome wire is wound onto them.
Power Control
In order to be able to regulate the air flow and current it is necessary to assemble the block, which will be placed rheostats. One of the rheostats is connected to the heating system and the other to the air ventilation. The on-off button is common to the whole system. Homemade soldering station with a hair dryer and controls to replace the factory version, and can be used not only to solder ordinary radio elements, but also to work with more serious items. When assembling the heat gun you must take care about the insulation of the coil from the metal case, otherwise a short circuit is inevitable.
A hot air gun made from an ordinary soldering iron
An ordinary soldering iron will work fine as a case for a soldering iron. All internal components must be removed. You must be very careful not to damage anything. For the assembly, you need a halogen lamp bulb as an insulator.
Next, the edges of the flask are cut with a glass cutter to obtain a glass tube, and on one side is attached to the tip with a socket made for the heater. The heater can be a nichrome plate up to 0.7 mm.
In the manufacture of the device carried out different actions, but it is better to adhere to this sequence:
- Winding the coil and introducing the quartz bulb inside the coil.
- To reduce the heat of the unit, the insulator is wrapped in foil.
- Mounting the heating element in the body and fixing.
- Connecting the compressor hose to the handle or installing a fan.
Such a simple design will not have a high performance, and the heating of the air flow does not exceed 300 degrees. For remaking with your own hands suit a soldering iron with 40W power, as well as an aquarium compressor as an air blower.
Upgrading an ordinary soldering iron can be done without removing the heating element, but with the removal of the metal part. The supply wire is led out into the side hole made in the handle, and instead of the wire, a sleeve is installed in the back for further installation of the air tube. The place of the output sleeve and wire must be sealed.
Next, the metal part of the soldering iron is installed in place, and a metal tube of suitable diameter is installed instead of the copper tip. A section of a telescopic version of a room antenna element can be used as a tube.
In a homemade soldering heat gun of this type, it is important to regulate the air flow, because with a high flow rate, the air will not be able to heat to the desired temperature.
From a plastic can
To make this construction, you will also need a nichrome coil, a power supply and a blower fan, and the following parts are used as housing elements:
- A small plastic can from tablets;
- Aluminum tube from the condenser;
- A plastic lid from a coffee can;
- Steel tube as a nozzle.
To assemble the device it is necessary to cut off the bottom of the plastic can with a stationery knife. A cooler is glued into the lid from the coffee can, and the case from the condenser is mounted into the lid from the pill can, along with the prepared heating element. All wires are brought outside, after which the lid with the cooler is put on the can with the help of thermal adhesive. Such a device is quite compact and does not require an additional holder, and as a nozzle can be used not only steel tube, but also the ceramic elements from the heating system of an old iron.
Soldering basics
Before you start making a soldering dryer based on a soldering iron or a regular hair dryer, you should first know how the process of soldering with this tool works. With this information you will avoid many assembly errors and be able to build a properly functioning unit.
Operating Principle
- During soldering with a hair dryer a jet of hot air or radiation produced by a soldering device affects the work surface.
- The printed circuit board, as well as the chips located on it are made of plastic, which has great difficulty absorbing heat from the air.
- The soldering points, as well as the metal leads of the chip have a metal base. They conduct heat very well and get most of it from the air that is blown from the nozzle of the hair dryer into the area of the board.
Keep in mind that before you work, all other metal elements on the board, including electrolytic capacitor housings, heat sinks of microchips, located in close proximity to the work area, should be protected from the effects of hot air or radiation using special shields of textolite, which should be pre-fixed to the board.
Features of soldering and brazing
Now it is time to know how to unsolder or solder a specific chip.
- First of all it is necessary to tin the contacts. An ordinary soldering iron can help. just draw it across the pins.
- For soldering you need PIC solder and soldering acid. You can also do this with a hair dryer, but to apply the solder you will need to use a soldering iron anyway.
- In the next step, clean all the tracks between the pins with a needle. This is to ensure that you do not inadvertently solder the tracks together when soldering. At the same time you should make sure that there are no traces soldered together on the board.
- Next, you can directly install the chip in place. To place it you need tweezers, and it is fastened using a soldering iron, which you need to heat all the pins evenly.
- During soldering move the hot air gun around the chip to heat all the pins evenly. When you have done this, gently press the chip with tweezers against the board and blow on it. That way you will cool the pins down and help them solder in faster.
- After that we take a needle and check if all pins are attached. If one of them does not, you need to solder them and clean the paths between the pins with a needle.
You shouldn’t have any problems with unsoldering the chip. To do this you have to move the dryer along the soldered pins. After they all come off, you can remove the chip. But here you have to make sure that all pins are heated evenly. Then they can be easily disconnected. During this operation it is important not to overheat the chip, otherwise it will no longer be suitable for further use.
Tool description
Homemade soldering station with a hair dryer is partly similar to a construction hair dryer, only the power and size are smaller, special mini nozzles are installed to supply air to a small area. Industrial versions are represented by a combination of a soldering iron and a heat gun, as well as two temperature controllers that allow you to make the air hotter or lower its temperature.
The principle of action of the heat soldering iron is quite simple:
- The air flow with high temperature is directed to the chip, making it more malleable.
- Together with the circuit itself the tracks to which you want to connect the product are heated.
Which is better: professional or homemade tool? In the professional provision of services for repair of modern home appliances and other electronics, it is best to buy a device that will be complete with interchangeable nozzles. Sooner or later it will pay off. If the repair of electronics is carried out rarely, you can get by with a homemade version.
Based on the cooler
Make a hair dryer with their own hands at home is easiest, if you use the turbine principle of blowing air, implemented with any suitable for this purpose small-sized fan.
A hair dryer for soldering can be homemade on the basis of the cooler, which is equipped with a power supply unit of any stationary computer.
In this case, the fan is built into the handle of the heat element of a refractory tube with an electric spiral, passing through which the air will be heated, and then enter the soldering zone.
The outer part of the body of the soldering iron must be sealed, which prevents the possibility of air suction into the surrounding space. To assemble the heater, you need a nichrome wire wound as a spiral onto a ceramic tube.
The total length of the winding is chosen so that the resistance of the entire wire section is about 70-90 ohms.
The individual coils of the coil, wound on a ceramic base, must be placed at a certain distance from each other. For the safe operation of the heater this distance should be about 1-2 mm.
About the heater temperature and the choice of material for its body
Operating temperature of nichrome spiral should not exceed 1000 ° C. You can roughly determine the temperature of red-hot spiral by its color. The table shows the temperature in degrees Celsius.
This table shows the melting point values of some metals.
As you see, copper, brass, or steel is best for the heater body. But, copper and brass oxidize quickly at high temperatures. So it is better to choose steel or nickel plated steel.
If you have any defective lithium-ion batteries at your disposal, you can make a tube out of the body of one of the cans. The jar shells of all lithium-ion batteries and rechargeable lithium-ion batteries are made of stainless steel.
The picture shows a disassembled laptop battery. Can body diameter is 16 mm, length. 65 mm. How to disassemble a notebook battery is explained and shown here
And this picture shows the disassembled battery “EN-EL1” from Nikon cameras. The diameter of the can is 14mm and the length is 48mm.
The cans’ contents of lithium-ion batteries and rechargeable lithium-ion batteries are extremely toxic! Therefore, it is necessary to disassemble the cans in the open air, and the removed products must be corked in a secure container and handed over to the point of battery recycling. Such items are usually available in large supermarkets and specialized stores.
Technical data
The fan of the hair dryer is powered by a 12 Volt DC power supply.
The heating element of the hair dryer is powered from a 0 12 Volt AC source. With it, you can change the temperature of the air flow, from room temperature to 600 ° C.
Mini hair dryer parameters at temperature limits.
The diameter of the nichrome wire of the heating element spiral. 1,2 mm.
Power supply voltage of the fan. 9 Volt.
The time of the dryer entering the selected temperature mode. 1 minute.
I did not make a special power supply for my hair dryer, so I have at my disposal universal sources of different power.
If you do not have a suitable power supply, you can adjust the resistance of the coil to one of the output voltages of a computer ATX power supply or make the simplest power supply from the ballast of a burnt CLL (Compact Fluorescent Lamp). For a detailed description of redesigning a power supply, based on a CLL, see here
On the picture, a schematic diagram of a switching power supply for a miniature soldering iron, based on a CFL ballast. The red color indicates the additional elements. The TV2 pulse transformer has two secondary windings. One of them feeds the fan and the other one feeds the coil of the heater. The switch S1 is used to adjust the coil temperature.
Car bumper soldering tips
The time of metal bumpers seems to have gone irrevocably. Today car manufacturers prefer to make this part out of plastic. This solution makes the vehicle more lightweight, but it has disadvantages: the plastic bumper is quite easy to damage, it is not an uncommon phenomenon in road accidents (especially often the front bumper suffers).
It is not always reasonable to change the damaged part; in many cases it can be repaired by soldering. You can do it with some skills and desire at home.
Choosing a hair dryer for soldering plastics and microchips
Such devices are not often used in everyday life. Some people haven’t heard of them and have no idea how a heathen can help with a lot of household and specific problems.
And still the main aim of such devices is to help craftsmen in soldering out radio components and repair of products made of PVC and other materials amenable to melting.
The appearance of such equipment is similar to construction, the differences are in dimensions and special replaceable tooling.
