To remove the insulation from the outside most often use a tool with a special heel. This is a specific knife that can not be used for any other work. That’s why its purchase will be beneficial primarily to a professional electrician, who regularly encounters such procedures. For home masters-amateurs bought tools has a rather high price, and the frequency of its use in the economy does not justify the expense of its purchase. For this reason, a cable stripper is sometimes made by hand from improvised materials.
The look of a fixture with a heel, bought in a store, promises a high level of usability. Knife is equipped with a rubberized grip to hold it firmly in your hand. Besides, there are special notches on rubber cover, thanks to which it does not slip and fits well in the palm of the hand. The ergonomic shape of many models also has a beneficial effect.
Blade of these knives is made of quality steel, and it is double-edged, which facilitates dissolving of insulation in both directions. from yourself and towards you. There is a small plate, called a heel, welded on the end of the blade allowing to safely strip cable without damaging internal winding. Its size varies depending on the wire thickness. the knife with a wide heel is suitable only for thick multicore cable, but the tool with a small one can remove the insulating layer from any wire. So the second method is of course the most universal.
The only disadvantage of such knives for wire stripping is that they are very expensive, but for electricians their purchase will pay for itself in the shortest time, allowing them to quickly and professionally strip insulation from flat cable.
It should be noted that a knife with a heel is designed exclusively for stripping flat cables. It is of course possible to adapt it to any type of cross-section, but when cutting a round cable there is a big risk of damaging the internal conductors.
Knives are also available without a heel. They look the same as ordinary ones, or they have a small hook. It is also relatively convenient, and the price of such models is much lower, but their use increases the risk of damage to other layers of insulation.
Making it with your own hands
To avoid having to spend a lot of money, you can make a cable stripper yourself out of the available tools. Each craftsman uses his own materials that can be found in the garage or closet. However, a rough set of everything needed would look like this:
- Blades from a paper knife.
- A handy handle, such as that of a chisel, or simply a block of wood that feels good in the hand. It is possible to use a metal profile, into which a bar with a slightly smaller cross-section is inserted.
- A boron drill or mini drill.
- Diamond cutting mini-disc for drills.
- Solder and soldering iron.
First of all, on the tip of a clerical blade with a diamond microdisk a kind of foot for the future heel is milled, in which a hole is sawed to the size of this very foot.
The blade is sharpened on the other side, then the heel is put on and carefully soldered on with a soldering iron. After soldering, it is necessary to round off and grind its surface well, so that in the process of work it could not damage inner layers of insulation, and also to improve sliding in thickness of wire.
After making the blank, proceed to the handle. A thin flat hole is sawed into the wooden rail, into which the blade itself is inserted. Then the bar is slid into the aluminum profile and fixed with a screw to secure it. At this stage, the work on the self-made electrician’s tool can be considered complete.
If a chisel or a cutter is taken as source, then the number of work steps is significantly reduced. they come with a convenient handle already ready, so it remains only to process the cutting part and solder the heel.
Among the reviews of customers regarding the functionality of the knife with a heel you can meet the facts of obtaining injuries of fingers while working with the product. The main reason of such facts is elementary nonobservance of safety measures. To avoid cut fingers it is necessary that the holding hand was always behind the blade and in no case in its way. For other questions, the answers are placed in a separate block below.
Q Can the product be used to strip the insulation from live conductors??
Theoretically it is possible, but in practice it is totally ineffective. This tool is intended for stripping primary insulation. The cutting edge must be perfectly sharp for that. Improper use means that the blade comes into contact with hard objects (metal wires in this case), which will cause the blade to dull quickly and reduce its effectiveness.
Q The voltage that the handle insulation is capable of protecting against is indicated on the product. Does this mean that the knife can be used on live cables??
Of course not. Any work involving the breaking or stripping of insulation from live parts must be preceded by a power outage. Markings on the handles indicate the ability to withstand a certain voltage in case of unauthorized activation.
Question When working with a knife you notice that the insulation of the inner cores of the cable is damaged. It is insignificant, but the tendency is alarming. What can be caused by such a disorder?
There can be two reasons: the first. the heel has lost the smoothness of the surface, the second. the user can not maintain the angle of the blade (with an increased angle, the heel begins to “dig in” and can damage the insulation of the current-carrying cores). To normalize the operation, check and, if necessary, grind the heel, and make sure that when cutting, the heel moves parallel to the conductor, without excessive tilting.
it can be noted that, like any tool, a heel knife has its advantages and disadvantages. After getting acquainted with them you can successfully use the device for many years. In addition, you can make a device for removing the shell with your own hands, getting a new tool in your arsenal and saving quite a significant amount of money.
Usually, the plastic insulation is stripped mechanically (with a knife or side cutters) or by melting. Enameled wire insulation is stripped mechanically (by scraping with a knife or sandpaper) or chemically.
How to properly strip plastic wire with a knife
It is not correct to cut the insulation in a circular pattern with a knife blade, which is perpendicular to the wire, while applying considerable force to the stripping process.
This cuts into the copper strand and the wire can easily break at this point. This is especially important when stripping thin wires, diameter 0,6-0,8 mm. They break after such stripping after a few minor bends.
It is necessary that the blade should be almost in one plane with the wire axis. The insulation is cut along the conductor, the remaining on the wire is taken aside and also cut.
How to properly strip wire insulation with side cutters
A second mistake is often made when removing insulation with side cutters. Usually, people pick up the tool as they have to, without paying attention to the orientation of the cutting edges.
If the sharpening side is in the direction of wire cutter movement, a considerable clamping force must be applied. The wire can easily break off with the insulation.
The sharpening side of the diagonal cutters must face the opposite direction of the tool’s movement, as shown in the photo. As a result, the cutting edges, even with a slight touch of the insulation, cut into it, and the insulation is easily removed with a tube without notching the wire.
Removing Plastic Insulation by Melting
Modern electric wires are usually insulated with PVC or polyethylene, which have a melting point of between 105 and 140°C. Therefore, with a soldering iron or other heating device, it is easy and safe for the wire to strip its insulation. To do this, you just need to run the end of the soldering iron tip, pressing on the circumference of the insulation in the right place. The insulation heats up, melts and is easily stripped off by hand.
As you can see, the insulation came off perfectly, without harming the copper wire.
If there are a lot of wires that need to be stripped of plastic insulation, it is advisable to use a special tool. A wood burner is very good for this. They used to make these under the name “Pattern”.
The method of stripping insulation by melting is indispensable when working with old electrical wiring. The plastic will age over time and become very hard, like bone. A piece of wire only 3 cm long protrudes into the junction box in the wall. A knife or wire cutters can’t reach the insulation. In this situation only melting will solve the problem. You can soften the insulation by heating it with a match or a gas lighter, and then already remove it.
Removing insulation from enameled wire
If the diameter of the wire is more than 0,2 mm, the most suitable way of stripping is to use abrasive paper or scraping the enamel with a knife.
To remove with sandpaper, you need to bend a small sheet of fine sandpaper in half, put the end of the wire inside between the bent halves of the sheet and pull the wire through without squeezing hard with your fingers. Repeat the operation by turning the wire until all the enamel is removed.
To remove the enamel with a knife, you need to put the end of the wire on any hard surface and turning the wire in a circle, scrape off the enamel until the end of the wire is completely clear of varnish.
In the case of stripping the wire with a diameter of less than 0,2 mm, it is difficult to remove the enamel mechanically without damaging or breaking the conductor.
But it is easy to remove the enamel thermochemically, using a soldering iron and a piece of chlorvinyl insulation. For this purpose it is necessary to pull the end of the wire between the sting of the soldering iron pressed to the chloro-vinyl. Chlorine released from heating will clean the wire from the enamel.
This method is indispensable for removing the enamel from the wire type licorrat, which is widely used in radio communications for winding high-frequency inductance coils. Licker wire is a lot of thin wires covered with enamel and twisted into one conductor.
Enamel can also be removed with aspirin, you put the wire on the pill and press it with the soldering iron, and then pull the wire through. The wire is immediately tinned.
Removal of fluoroplastic insulation
Fluoroplastic is a chemically produced polymer that is resistant to organic solvents and will not be dampened by water. Characterized by high electric strength, resistant to temperatures up to 300°C. Perfect insulating material, but expensive. Therefore, it is used only in technically justified cases. Household fluoroplastic wire is used by hams, as it is not melted when soldering with a soldering iron, takes up little space and has an aesthetic look.
Fluoroplastic insulation is a thin, narrow strip of tightly wound on a stranded thin copper wire. You can only free such a wire from its insulation physically.
It is best to use a knife for this purpose. Having pressed the wire to the pad, a knife scrapes off the PTFE to the required length.
After the wire is exposed, it is bent aside and the remaining unnecessary fluoroplastic is cut off. The result is a neatly stripped of fluoroplastic insulation conductor ready for soldering.
Insulation made of rubber, fabric and other insulating materials is removed by one of the mechanical methods described above. The main rule is not to make any notches on the wire strands.
Principle of mechanical removal of cable insulation and braid
Spot welding for batteries with your own hands
The mechanics of cutting a cable or wire is to make one or more longitudinal cuts in the insulating layer. The sheathing is usually made of PVC or rubber. These are pretty soft materials. To cut them, you just need to pull the wire through the sharp blade of the cutter.
The principle of mechanical cutting of cables is that the wire is fed into the machine’s socket by tapered rollers that are driven by an electric motor. The cable is cut with a knife, only metal appears at the output, the removed braid and insulation remain at the back of the equipment.
The design of the wire cutting machine may be different, depending on the characteristics of the processed product: it is the wire diameter, insulation coating thickness, multi-core filling, the presence of armored braid.
How to strip wire and power cable?
The easiest way to remove the insulation from a wire is with a regular knife. In this case the upper protective layer is removed with longitudinal cuts, and the sheath of the contacts is cut in a circle with a bit of the blade stuck inside. In this case you will not spend much time on such an activity, but there is a risk of damaging the conductor, especially if the coils are thin.
If you decide to use a knife, it is advisable to use a special one, the blade of which is slightly curved for easy stripping. Pay attention to the handle, it must be made of a material that does not conduct electricity.
Experienced electricians advise stripping wire insulation with a knife according to the following technique:
- Place the conductor on the table.
- Press down with the index finger of your left hand (if you are right-handed).
- With your other hand take the stripping tool (in this case a knife) and press a little into the protective sheath.
- With the index finger of your left hand slowly turn the material one full turn (very handy if you decided to strip the sheath from a round power cable).
- Tighten the cut piece of insulating material (can be PVC, rubber, silicone, or even paper sheathing).
That’s the essence of the job. As you can see, there is nothing complicated, but there is a high probability of damaging the contact, which makes this method not very effective.
On how to make an electrician’s knife with their own hands we told in a separate article. Step-by-step instructions with photo examples explain the whole essence of the work!
The second method of stripping wire and power cable insulation is to use a soldering iron. In this case, the stinger is heated to the required temperature, and then you remove the sheath by analogy with the previous variant (you twist the conductor with your finger, leaning the soldering iron against the insulation). As a result, the extra piece of sheathing is easily separated from the remaining part. The disadvantage of this method is that when the material comes in contact with the heated sting, an unpleasant smell will go through the room. In addition, the soldering iron is not recommended if the shell is rubber.
By the way another tool can be used with the same method. the so-called “roaster”. When using it you will hear all the same unpleasant smell, so you should use it only in extreme cases.
There are also universal tools for stripping wires and cables, called manual strippers. These products are more functional, t.к. Allow you to manually adjust the diameter of the cores so that when you cut them, you don’t damage them. To use the strippers is quite simple. you fix the desired contact and scroll through the guiding arrow one turn (as shown in the photo).
there are also special strippers on the market that can be used for stripping insulation of cross-linked polyethylene without burning. Such tools have a high price (over 6000) and are used for industrial purposes, so we will not dwell on their review in detail.
Video overview of the professional puller:
And the last and best method, according to electricians, is using a tool called a stripper. The given device is designed for automatic stripping of insulation from wires. The design provides not only a section regulator, but also special cutters and a crimper (used for crimping lugs). Using the stripper is not difficult: the cable is fixed in the jaws, the handle is squeezed and unclenched. The result is a quickly stripped wire without damage. It can be used to peel off the insulating material from the most popular types of conductors: VVG, PVA, NYM and many others.
In fact, if you have already decided to engage in electrical work, then make sure to buy a stripper. (usually 300-500).
At the same time, the tool‘s advantages are as follows:
- used both for very thin sections, from 0,05 mm 2. as well as with thick 6 mm 2 ;
- can additionally be used as wire cutter and baler;
- applies to any kind of insulating material: silicone, polyvinyl chloride, rubber, fluoroplastic sheathing:
- can easily strip the sheath, even from loops, twisted pair and stranded wires
- does not damage the current-carrying part of either aluminum or copper wire;
- easy to use;
As you can see, this device has a lot of advantages and no disadvantages compared to alternatives. That’s why we recommend you to choose a stripper for stripping wires and cutting cables. This tool has many positive reviews on thematic forums from experts in the field of electronics.
In the field, many electricians use their own teeth to remove the protective sheathing. Please note that this method is quite dangerous for the enamel of teeth, so it is not recommended to use it! If possible, it is better to use pliers or side cutters, an electrician should always have them handy!
We also recommend watching the video, which shows how each of the tools for stripping wires works:
How to make an electrician’s knife with your own hands
The electrician’s knife with his own hands can be made from two blades of office knives or a small piece of metal, as the working part of the tool should be small. In the first case, the sequence of actions is as follows:
- It is necessary to saw a rectangular piece on the blade of the office knife to form a sufficiently narrow protruding part (spike).
- From the other blade, an oval or round heel of the required diameter is cut out, a line of contact with the spike (slit) is drawn in it.
- Both parts are connected by soldering.
- The outer part of the heel should be sanded to make the surface smooth and the shape slightly convex.
- It remains to cut out of wood or plastic pads to size and attach them with epoxy glue.
- It is better to sharpen the blade only from the outside and guide it in the process of work from yourself.
With this primitive knife you can act if you need to repair wiring at home, but be sure to de-energize it first.
A more perfect tool is obtained in another way:
- It is necessary to take a strip of carbon steel 3-5 mm thick and make a curved blade drawing on it together with the heel.
- The workpiece is cut with an angle grinder or on a machine tool.
- Excess metal at the junction of the base of the blade and the heel is thinned with the same devices, so that the latter part stands out.
- Then it is necessary to sharpen the blades (one or both).
- The heel is also grinded until smooth, it must be a little bit convex, but without jagged edges.
- Handle pads made of wood, plastic, rubber hose are fixed on the blade.
The last stage is performed using epoxy glue, but it is supplemented with fasteners for reliability. For them you will need to drill holes in the shank of the blade and on the pads themselves.
We recommend reading about how to choose a carving knife for work in the kitchen. From the article you will learn about the characteristics and purpose of the carving knife, its varieties, cost, the rules of processing knives for meat.
And here’s more about the pros and cons of electric knives.
There are many tools for removing protection from cables, and a specialist should only choose a good quality factory knife. If you need to repair the wiring at home, you can buy an inexpensive product with a heel or make it your own hands. The latter is not difficult, and the materials for the knife are quite available.
How to make a knife with a heel by yourself?
As we have seen, a montage knife equipped with a heel is a very handy tool that has serious advantages. Nevertheless, it has one serious disadvantage. a high cost, due to which many people can not afford such a purchase.
If you have to do electrical work only periodically, as is usually the case in the home, the purchase of a specialized tool is impractical.
However, such an electrician’s knife can be made with your own hands, this procedure does not present any difficulties. Let’s understand in detail how to perform it and what we need for this.
Materials for work
To make a homemade knife with a heel for wire stripping, first you need to stock up on the accessories that are listed below:
- Blades for office knife (2 pcs).)
- The aluminum profile that is used to make the handle. A piece of metal base from mosquito netting used for PVC windows will do.
- A slat made of wood, which must be slightly inferior to the profile in its cross section.
After all the necessary materials and tools are ready, you can proceed directly to the assembling of the knife with a heel.
Order of manufacture
A homemade montage knife is made in the following order:
- Cut out a spike on the stationery blade, to which the heel will be attached.
- Grind off the extra sharpening so that only the edge remains sharpened.
- Sharpen the opposite side of the blade.
- Make a piece of second blade into a heel with a slit that matches the thickness of the cutting blade.
- Use a soldering iron and solder to attach the manufactured heel to the first blade. Give its edges an oval shape, so that during the work of the tool it could not damage the insulation of the wires and their metal base.
- Insert the blade into a piece of metal profile and cut it inside using a wooden slat with a kerf.
- Drill a hole in the handle so that it overlaps with the hole you have in the blade.
- Insert a bolt in the hole and secure the other side with a nut.
That’s it, the tool is ready to use.
A slightly different technology of making a knife with a heel on the
A knife with a heel for cable stripping
A wire stripper with a special heel is a great invention that makes it easier for the electrician to cut through cables and wire. With it, the laborious work of stripping the outer sheath of a conductor becomes a simple operation, taking only a few seconds. However, the price of the finished product in the store is a significant amount, which makes the user think about the advisability of such a purchase. One thing. a professional electrician, daily faced with the need to use it, but for the home craftsman, such a purchase will be an unjustified waste. There is a way to solve this problem by making an electrician’s knife with your own hands. In the article we will tell how to make a knife with a heel for stripping, give detailed instructions.
Things to Consider When Stripping Wire Cores
Many people do not pay much attention to what tool to use to strip the insulation from the cores of cables. However, it is the tool that plays an important role in the durability of the installed connection. As an example, you can consider the use of an ordinary cutter. Cutting an entire length of insulation can damage live wires in a flexible cable. If you trim the insulation in a circular manner, then grooves are formed on the cores, along which they can later break off.
The same is true for stripping wires with side cutters. Of course, a professional electrician with experience can easily strip the insulation with any tool without damaging the cores, but such specialists are very few. What about those who don’t have enough experience? In this case, some advise to make a special device for stripping the insulation. Of course, there are “individuals” who use their own teeth for cable stripping, but Homius editors warn the dear reader against such actions. That’s not what people’s teeth are for, after all.