Many home craftsmen do not know how to bend a profile pipe on their own, without turning to specialist workshops. In fact, performing such an operation is not so difficult if you acquire the necessary equipment.
1 Bending a profile pipe with your own hands - practical tips
Thousands of owners of plots outside the city and private housing constructions literally put their souls into their real estate. They try in every way to make it original appearance. Moreover, such people strive to perform many landscaping operations with their own hands, truly being proud of their work.
Very often, when arranging a country “estate”, a person needs to bend a profile pipe, which is now very actively used for various purposes, from the construction of fences to the installation of an unusual canopy over the entrance to the house. Bend the pipe manually without using special devices designed for such purposes is difficult and sometimes simply unrealistic.
This statement is especially true for profile pipe products. If the pipe round section You can also heat it up, wrap it around a special template, securely fasten one of the ends of the structure, and then try to bend it at the required angle, but for profile products this method is absolutely not suitable.
There is only one way out: use a device for bending a profile, thoroughly study the principle of performing the operation with its help, and solve the problem of giving the pipe the desired configuration. Let us note that even with the help of special equipment it will not be at all easy to carry out such a procedure - there is a high probability that under the hands of an inexperienced person the pipe will be flattened or its cross-section will be deformed.
To minimize the risk of such an unfavorable development of events, it is recommended to first freeze the pipe by placing it in a large industrial-type refrigeration unit. If there is no large refrigerator, it is recommended to perform the bending operation in winter, when the temperature outside is sub-zero.
Before freezing, one edge of the profile product should be securely plugged, then fill the pipe with plain water and close the other end of the structure. After this, we place the workpiece in a chamber or take it out into the cold, wait until the liquid in it is completely frozen. Frozen water will prevent the product from deforming during the bending process. And the process itself, believe me, will be much easier.
An alternative to the described method is a technology in which sand is poured into the pipe, plugs are placed at both ends of the structure, and then 2-3 small diameter holes are made in it. They are necessary so that subsequently, when the workpiece is heated, the gases formed in the pipe have an outlet. If holes are not made, there is a risk of deformation of the structure.
Having completed all the specified operations, you can begin bending. To do this, using a blowtorch, you need to heat the selected area along which the bend will be made, and then boldly bend the pipe. Described preliminary stages(freezing, filling with sand, heating the profile product) will not have to be done if you use modern pipe benders designed specifically for working with pipes.
2 How to bend a profile pipe using a pipe bender?
By such a device we mean special devices several types, which make it possible to bend structures made of round or profile steel with a minimum of manual effort (for example, for home greenhouses, canopies, and so on). All pipe benders are usually divided into two large groups:
- Roller (they are also often called profile benders): used for bending profile pipe products along smooth radii. IN in this case bending is carried out according to the principle of pipe rolling.
- Hydraulic lever: they are usually used to bend metal structures at the required angle, applying a certain force in a given place. The ease of the procedure is ensured by the fact that the force is set by a lever.
The advantages of using pipe benders are as follows:
- reduction of human effort to bend ( manual labor when using a device with an electric drive, it is completely reduced to zero);
- refusal to install additional fittings and carry out welding work when installing pipelines);
- no flattening or creases (the metal retains all its technical characteristics);
- guarantee of obtaining curved pipes with precise dimensions.
In addition, pipe benders provide truly elegant appearance structures that are made from solid pipe products. From the point of view of decorative appeal, such designs can be considered impeccable. Try to achieve similar results if you do not know how to bend a profile pipe using a pipe bender. It is unlikely that you will succeed.
The choice of a specific machine for bending pipes depends on the material of the products, as well as on the type of work that you will carry out using steel or (as you yourself understand, plastic structures there is no need to bend with a pipe bender). For example, copper pipes for installing a heating system or water supply are bent simple pipe bender manual type, which is intended specifically for this material.
And now hardware for plumbing work, they are bent using a device that can cope with stronger and harder material. Naturally, they work with profile pipes exclusively with a roller device, which was created specifically for such activities. By the way, it makes it possible to bend round seamless pipes with thick walls.
3 Popular models of domestic manual profile benders
IN construction stores you can easily find different types foreign-made pipe benders. But their price often does not suit Russians, who prefer to buy proven domestic mechanisms. Fortunately, in terms of their capabilities they are no worse than imported products.
The most popular devices for bending profile products are the manual machines “PG-1” and “PG-2”. The first of them costs no more than $500, it is made in a compact form, being mobile (portable) equipment. Due to this, the mechanism can be used directly at the execution site installation work for bending copper, metal and with dimensions no more than 40 by 40 millimeters.
Structurally, the device consists of a frame with three rollers attached to it. The pressure roller (it is central) allows you to pull the pipe. The ease of turning this roller is due to the presence of a comfortable handle. The width of the rotating components of the machine can be changed to work with pipes of different sizes.
The profile bender "PG-2" differs from its brother in a more powerful design. It easily bends pipes made of the above materials measuring 30 by 60 millimeters. It can even be used to bend pipes into rings. It is clear that the cost of such a model is higher. You can buy it for 750–800 dollars.
We hope that you now have no questions about how to bend a profile pipe.
Bend profile pipe can be done independently, without the use of expensive and bulky machines. If all the rules are followed, the work will turn out to be of no less quality. Let's consider several options that allow you to bend pipes yourself.
Bending a pipe using a grinder
To perform this procedure you will need an angle grinder Grinder) and a welding machine. Let's move on to the work process:
- Before bending, it is recommended to fix the pipe (for example, in a vice). This will keep it in one plane. If there is a weld on the pipe, it must be placed on outside bend so that the metal does not come apart.
- Calculate the bend radius and mark the bend location. Take a grinder and make transverse cuts along the length of the mark (on 3 sides). After this, you can bend the product without difficulty.
- The resulting cracks must be welded and cleaned. Try to do the work slowly and carefully - this will allow you to achieve good quality and not damage the pipe.
Bending a pipe using a spring and a blowtorch
You will need steel wire with a diameter of 2 mm. Make a spring out of it so that it can fit inside the pipe without dangling. You can also purchase a ready-made spring for bending pipes. Insert it into the pipe, mark the bend and heat it with a blowtorch. After this, you can easily bend the pipe using a rounded blank. If the resulting result does not suit you, you can redo the work, but it is preferable to immediately carefully perform all the steps.
Bending a pipe using sand and a gas torch
This method will allow you to give the pipe a suitable bend without the risk of cracks and flattening. You will need quartz or purified sand, gas welding(burner), two wooden plugs and a drill. Let's consider the process in order:
- Instead of quartz sand, you can use regular sand. But it must be cleaned first. Sift the sand and dry it thoroughly by heating it over a fire or burner. The sand should be heated until it stops smoking. When everything is ready, pour the cooled sand into a clean container.
- Insert a wooden plug into one end of the profile pipe (to a depth of no more than 10-20 cm). Completely fill the pipe with quartz (or purified) sand and close the other end with a plug. This filling will avoid destruction during the bending process. If there is no sand, the material will simply deteriorate.
- Make a small hole in one of the plugs. During heating, air will escape from it.
- Mark the area that needs to be folded and heat it with a torch. Then give the pipe the required form. Try not to overheat the metal - this can lead to the formation of scale and loss of quality of the material.
- When the pipe takes the desired shape, remove the wooden plugs and pour out the sand. It is recommended to heat the ends of the profile pipe - this will make the plugs easier to pull out.
Additional bending methods
There are methods designed for pipes made of specific materials which you can also use:
- For bending copper pipe(as well as brass and duralumin) you will need water and negative temperature. Plug one end of the pipe, then fill the pipe with water and cap the other end. Place the product in the cold and leave it there until ice forms. After this, the product can easily take the desired shape. You can also use melted paraffin, rosin or lead as a filling.
- For bending metal-plastic pipe You can use table salt. It must first be heated in a frying pan (until the salt crystals begin to explode) and poured into the pipe. When the hot raw material is inside, the pipe can be bent without much effort.
The variety of ways to bend profile pipes allows you to perform this procedure at home, without resorting to the help of specialists and expensive equipment. Try to follow the algorithm for creating bends and act slowly. In this case, the chances of creating a high-quality product are greatly increased.
Making metal structures with your own hands at home or in production often cannot be done without the use of curved elements. The rounded shape of pipe frames is found everywhere in private construction: sheds, hangars, greenhouses, garden arches, benches, swings and much more. All this looks aesthetically pleasing and lightweight. The most popular material for such structures is profile pipe; it is durable, lightweight, easy to install, and resistant to breakage and bending. Then the question arises: how to bend a profile pipe?
Bending a profile pipe: how to do it correctly?
The process of bending a profile pipe and a round one is not always carried out in the same ways; as a result, you can get a result different from the expected one. The square (rectangular) cross-section is difficult to bend, folds, cracks, breaks, flattening, axial twisting and other defects occur. To avoid this, let’s consider all the subtleties of the question: how to bend a profile pipe at home?
Before you begin bending, you should measure the internal height and wall thickness of the profile pipe. Due to the fact that the permissible bending radius of this range of products is not regulated, a value equal to the height of the inner wall of the profile minus twice the wall thickness is taken. These measurements are also necessary to determine the minimum permissible length of the bendable pipe section:
- If the profile height (A) is up to 20 mm, the minimum bending area should be 2.5*A mm;
- If the profile height (A) is more than 20 mm, the minimum bending area should be 3.5 * A mm.
Bending of a profile pipe along a radius is carried out taking into account the characteristics of the material and wall thickness. It is not recommended to bend tubular products with a large clearance and a wall thickness of up to 2 mm; flattening, creases, seam rupture and other deformations cannot be avoided. At home, it is better to use welding to form a bend.
When bending a square (rectangular) pipe with your own hands, the seam of the product must be placed on the side or on the convex side (not the concave side), so that the compression force does not directly act on the seam.
Ways to bend a profile pipe with your own hands
Owners most often cope with the arrangement of the territory around a private house on their own, building greenhouses, fences, gazebos, canopies, installing frames and structures from profile pipes. Such structures can consist of a large number of curved parts. The service for forming the required bending of parts can be ordered at the enterprise, where, using a special pipe bender (profile bender), everything will be done quickly and efficiently. However, many people bending a profile pipe with their own hands turns out to be of no less quality and even without a pipe bender, which is expensive and will not be needed in the future. There are several ways to do this at home.
How to bend a profile pipe using welding
Tubular products with a square or rectangular cross-section, the wall height of which is 30 - 40 mm or more, are difficult to bend, especially with small radii. To form a beautiful 90 degree bend from such material with your own hands, without a grinder and welding machine not enough.
Procedure:
- Make a bending template, which makes it easier to make several identical parts;
- Use a grinder to make notches along the pipe along the three walls, leaving one intact. The more notches, the rounder the bend will be;
- Fix one end of the profile securely;
- Using force, grasping the second end, gradually bend the pipe according to the template so that the cuts form the concave part of the bend. The bending plane should not be disturbed; you can use a mallet;
- Weld the cuts and grind the welding areas.
How to bend a profile pipe using fillers
The filler is used to obtain uniform bends without flattening and folds (corrugations on the concave part), filling inner space it distributes compression and tension forces over the entire surface of the bent section of the profile. The most tested filler is fine, dry, well-sifted sand.
This method may be accompanied by heating the pipe blowtorch or by incandescence charcoal, when heated, the metal will acquire plasticity, which makes bending easier. Tubular products with a wall height of 30 mm or more are hot bent.
Pipe products with a wall height of up to 20 mm bend without heating, and with a bending radius of less than 50 mm, no filler can be used.
Procedure for the hot method:
- Anneal the bend section of the prepared pipe;
- Make wooden plugs in the form of pyramids 10 bases long, which are 2 times larger than the lumen, make 4 longitudinal grooves on one for gas removal during heating;
- Plug one end of the pipe, gradually fill in sifted and calcined sand to the brim, compacting it by tapping. Cap the second end with a chopper with grooves;
- Mark the heating area with chalk, clamp the profile, placing the seam not on the concave side relative to the template;
- Heat the pipe until red hot, bend it with translational movements in one approach (re-heating is not advisable), observing the bend plane according to the template. Follow safety precautions;
- After cooling, knock out or burn out the plugs.
With a wall height of up to 10mm, we can safely bend a profile pipe with our own hands without heating or filler. In other cases, instead of sand, you can use a steel spring with dense square or rectangular coils. It should be slightly smaller in size internal dimensions pipes so that they fit tightly to the bend. The spring will also prevent unwanted deformations from forming during cold bending. They pull it out by the wire attached to the end turns, which goes out.
How to bend a profile pipe at home on a bending plate
This is another option for how to bend a profile pipe without a pipe bender, using devices you make yourself. These include horizontal metal or concrete slab with holes, stationary flat template with fixing element, workbench with mandrel. These designs are good for cold bending of thin tubular products. The principle of operation is simple: one end of the profile is clamped, and the other is pressed under force, bending around the prepared shape. Manual bending requires considerable effort and does not guarantee accuracy.
It should be remembered that rolled steel pipes have a plastic moment of resistance (spring effect), so the bend must be adjusted several times to the template.
How to bend a profile pipe with your own hands and bring it back to its original shape is a difficult task. For everything to work out as planned on the first try, you can’t do without a special machine.
Pipe bender for products with square and rectangular sections
A roll forming machine is a device with shafts, one of which, with free movement under pressure, uniformly bends the pipe the desired shape along the entire length. The shafts are machined to a specific cross-section. The pressure is applied gradually until the desired bend is achieved. The force is applied manually or using an electric drive or hydraulics. The home pipe bender is designed for a small amount of bendable products, professional can be used for serial bending of guaranteed accuracy.
Thanks to its design features, the profile bender qualitatively bends rolled steel pipes without heating, both in a separate section and along the entire length at different angles, in different planes.
It is also possible to make a bending device with your own hands; it will take a lot of effort, time and money, but the process of bending pipes will become easier. Manual machine for profile bending, it is easy to use, has small dimensions, and can be installed in a garage or small workshop. The pipe bender should be provided with a reliable, stable position; the work should be done slowly, constantly checking compliance with the template. The simplest option, suitable for thin pipes, is the Volnova roller machine. In a certain place of a workpiece clamped in a vice, a bend is formed by a roller, but good physical strength is required.
How to bend a profile pipe at home is not an easy question. There are many nuances to consider and everything to be done correctly so as not to spoil the material. Much attention is paid to the cross-sectional dimensions, wall thickness, calculation of the bending radius, and it is also worth deciding whether to use heating, filler or not.
When designing various metal structures Sometimes there is a need for correct deformation of a metal profile. For example, greenhouses or canopies made of stainless steel, copper steel and other products made from bent profile pipes give a more aesthetic appearance compared to rectangular shapes. In some cases, the use of bent elements in general design rather saves material than reduces the cost of the entire product.
A corrugated pipe is a metal product that has a rectangular cross-section and is empty inside. Speaking in simple words, this is an ordinary pipe, only not round, but square section. The wall thickness of the profile pipe can be different, from two to five millimeters. The wall thickness is selected based on the scope of application. This type of rolled metal is very popular and used in most various fields human activities, such as:
- Construction.
- Mechanical engineering.
- Manufacturing of metal structures.
Methods for bending a profile pipe in a factory
A profile pipe can be bent and bent in the factory using special pipe bending machines. The use of such machines allows you to achieve high-quality results. But it is worth noting the fact that such production is set up exclusively for bending large volumes of work, so it is extremely rare to order a curved profile of a certain size in the amount of a couple of pieces. When a profile is bent at the factory, it is preheated, which allows the metal to quickly take the desired shape.
Methods for bending a pipe at home
Many craftsmen are interested in the question: how to bend a profile pipe at home correctly? This operation can be done independently with the help of some devices or without them. Bending a profile can be done in several ways:
- With the help of sand.
- Using profile cuts.
- Using a manual pipe bender with special rollers for the profile pipe.
The first method is as follows. One end of the pipe is tightly closed (can be welded) and then clean sifted sand is poured inside the pipe. And the second edge also closes. Next, the pipe is securely fixed in a vice and heated using a gas burner. Then, using a lever, it is bent desired angle or semicircle. The sand in the profile prevents the thin-walled metal from pressing inward, thereby bending evenly.
This method is more suitable for single bending of a profile of small sections. In addition, this method has a number of disadvantages, such as a large amount of time spent on one product. Inability to make large semicircles. In most cases, the bending is of poor quality. With this method it is impossible to make two perfectly identical bends. This method can be called artisanal, but in some cases it is impossible to do without it.
How to bend a profile pipe without a pipe bender using profile cuts. First of all, it is immediately necessary to note the laboriousness of this bending method, but compared to the first method, bending with cuts allows you to get more quality product in the final result.
So, in order to get a profile, arched, it is necessary first of all to make a pattern along which the bending will take place. It can be made from a sheet of plywood and metal corners. You need to draw an arc of actual size on the plywood and screw metal corners along the entire line. Then you need to make markings on the metal profile. The markup is as follows.
On the profile you need to draw lines along which you need to make cuts using a grinder. The number of these cuts depends on the bending radius of the product. The smaller the bend diameter, the more cuts need to be made. The cuts must be made at equal distances from each other, this will ensure uniform bending. It should also be taken into account that the thicker the cuts, the better the final result.
After the cuts, the metal profile is applied to the middle of the pattern and securely fixed. Bending occurs using the method of gradually pressing the profile to the corners. After bending, the slots are welded to ensure strength.
This method of bending the profile provides high accuracy arcs, and if you need to make several identical bent elements, this method can be completely used. But as noted above, this method requires a lot of time, as well as additional costs.
Every craftsman who works with metal probably knows how to bend a pipe at home using a pipe bender.
A pipe bender is a device with which you can roll a profile under pressure, due to which one wall is stretched and the other is compressed.
This device consists of three rollers, two of which are located in a row and the third at the top above them. The third roller, using levers, presses the profile onto the lower ones. In this way, the entire profile is rolled.
This method is the most effective, since little time is spent and the result is maximum quality. Pipe benders can be different designs, it is also worth noting that this device can be completely assembled independently, without resorting to additional costs for its purchase.
If we compare all three methods, then the pipe bender will be the most effective. But if you need to bend the profile in a single case, it will be easier to use one of manual methods, since it is impractical to make a pipe bender in order to make one bent element. Of course, in this case, you can contact a workshop, and for a small fee, specialists will do this work efficiently.
Some home craftsmen have a question about how to bend a stainless steel pipe, since this alloy behaves very critically when bending. Stainless steel can only be bent using slightly heated pipe benders. This avoids cracks. The incision method in this case is ineffective and leads to additional costs. In addition, if the structures are then polished, the welding will look unsightly.
Greenhouse frame with square or rectangular cross-section attracts with reliability and service life. A very durable metal structure allows maximum light to pass through, because its racks, supports, and ties are much thinner than those of its wooden competitors. Metal is inferior in manufacturability. Without knowing the nuances, it is difficult to make an arched arc or a frame for a door from a straight blank. Because of these complications with a metal base, it is completely in vain to prefer to buy “green houses”. However, if you thoroughly understand how to bend a profile pipe for a greenhouse, you can build an inexpensive arched structure with your own hands at little cost.
The essence and problems of bending profile pipes
Bending of metal products, regardless of the cross-sectional shape, consists of giving them a partial or complete smoothly curved configuration. One of the common plumbing procedures is performed either under pressure alone, or under pressure in combination with heating the bending area. At this time, compressive forces with inside workpiece and tensile forces along the outer wall. Complications are that:
- During the process of changing shape, the material may lose the alignment of the segments, i.e. parts of the curved workpiece will not be located in a single plane;
- the stretchable outer wall in the bending area may not withstand the impact and simply burst;
- The compressed inner wall may, instead of uniform contraction, fold into folds resembling a corrugation.
Without knowing the intricacies of bending a profile, there is a risk of simply crushing the product, ruining the workpiece. But recklessness is not our way! Especially if it is accompanied by material losses. For the glory of rational economy, we will take into account all the vagaries of the profile and characteristics of the “iron” material. Let's not forget about the cross-sectional dimensions, the wall thickness of the profile pipe, the required bending radius and the elasticity of the steel alloy. Based on the specified parameters, we will choose the correct technological path - also known as the bending method.
Why do you need to know the profile characteristics?
Profile pipes from standard round version differs in cross-sectional shape, which can be square, oval, rectangular or flat-oval. According to GOST R regulations No. 54157-2010, a round product is also included in the list of specialized products. However, in greenhouse construction, products with a square and rectangular cross-section are most often used, for example, 40x20 mm profile pipes, because it is easier to attach the coating to their smooth, flat walls.
For a variety of national economic needs, products are produced in a wide range of sizes. It differs in configuration and cross-sectional area and, naturally, in wall thickness. The combination of sizes determines the plastic capabilities. In professional language, they are called the minimum permissible radius of curvature. This means that before you find out how to make a blank for a frame, you need to find out what is the smallest radius of flat round deformation that the blank can “survive” without damage.
To determine the minimum allowable bend radius of a square or rectangular profile, we need the height h because:
- products with a profile height of up to 20 mm will be bent without becoming unusable defective if bending is carried out on a section with a length of 2.5 × h or more;
- pipes with a profile height of over 20 mm will withstand deformation over a section of length 3.5×h or more without loss.
The indicated limits are necessary for those who are planning to make racks, shelves and frames for windows or doors. The thickness of the walls also makes adjustments to the area of limitations. Wide pipes with thin walls up to 2mm thick are generally not recommended to bend. It's better to use welding.
Home craftsmen who decide to make arcs for , need to take into account that products used in everyday life from ordinary carbon or low-alloy steel alloys tend to “spring” slightly after applying force to them. They seem to be trying to return to their previous state. Consequently, after a novice mechanic completes bending all the arches with his own hands, he will have to repeat the processing and again adjust the arches to the template. It is advisable to initially take into account the value of the plastic moment of resistance Wp. It is usually indicated in the documents of the building material being sold. The smaller the moment, the less fuss there will be with the fit.
Bending methods and their features
They bend profile pipes in both cold and hot states. Heat gas burner will significantly increase plasticity. However, material with a small cross-section bends excellently even without unnecessary temperature effects, because thin pipes are quite flexible and more easily amenable to the force applied to them.
There are no exact instructions regarding the use of heat for bending. The standards indicate only the dimensions of round products, according to which it is necessary to apply flame to the treated area with a diameter of 100 mm or more. With square and rectangular shapes, everything happens a little differently. Based on the experience of folk craftsmen:
- with a profile height of up to 10 mm, the workpieces are definitely cold bent;
- with a profile height of 40 mm or more, the pipes are bent with heating.
How simpler and easier it is to bend a profile at home with a height in the range from 10 to 40 mm, the performer will have to decide on his own. If the craftsman has a profile bender in his arsenal, he can use it to create an arched curve without heating. There is no apparatus, it is better to try your hand in advance. To do this, clamp one end of the material in a vice. Place a pipe larger than the height of the profile onto the other end and pull the “shoulder” enlarged in this way. If it works, there is no point in heating metal products.
Option #1 – bending with heating
We will deform the unyielding material using the hot method, after filling it with sand. This will improve the quality of processing and ensure uniform bending. Let's stock up on canvas gloves for hot work and get started:
- from scraps of timber or logs we will make two pyramidal plugs, the length of which should be 10 times the width of the base. Base area of each homemade cork should be almost 2 times the square or rectangular hole, which she has to shut up;
- Let’s try on how the plugs “fit”, then select longitudinal grooves on one of them on four sides. They are needed to release the gas that accumulates when the filler is heated;
- pre-anneal the workpiece in the area of the future bend;
- Let's prepare the filler. Let's take pure construction sand medium grit. In the absence of bulk building materials, we will use sand from a children's sandbox. We first sift it through a sieve with 2 or 2.5 mm mesh to remove gravel and trash from the packing. Large inclusions on the surface of pipes can form unnecessary relief. Then we will “pass” the sifted mass again, but through a fine sieve with 0.7 mm cells, so that the dusty particles do not sinter when heated. We will return all the screenings, as well as the filler, to the sandbox upon completion of the actions;
- calcinate the filler at a temperature of 150ºС;
- Let's plug one end with a wooden plug, which has no channels for venting gases. We will install a funnel at the second end. Depending on the size, we will install the workpiece at an angle or perpendicular to the ground. We will pour the filler in portions through the funnel. Periodically tap the walls of the product from bottom to top with a wooden or rubber mallet to compact the sand. A dull sound will indicate sufficient compaction;
- close the filled blank with a second plug;
- Mark the heating area on the workpiece with chalk;
- We secure the workpiece either in a vice with a template or in a clamp. We install the material with the welded seam so that the welded joint is on the side. It is not advisable to stretch or compress along the seam;
- heat the marked area red-hot and carefully give the workpiece the required shape. We bend in one step with a progressive, unsharp movement in a strictly horizontal or vertical plane;
- After cooling, compare the result with the template. If everything is in order, knock out or burn out the plugs and pour out the sand.
The described method is good for forming single corner bends, because It is strongly not recommended to heat the pipes several times. Metal loses strength from repeated temperature shock. However, when creating a rounded arch, repeated heating is inevitable. After all, it’s impossible to do the job in one go, but when cooled to a light cherry hue, i.e. up to 800ºС, the workpiece may simply burst.
Option #2 – cold method
Plastic deformation of rolled profiles “cold” is carried out both with and without filler. Material with a profile height of up to 10 mm does not require filling. It is better to fill a thicker pipe with sand or rosin. An alternative to sand filler is a tightly wound spring, the dimensions of which will allow it to be tightly installed in the cavity at the processing site. The spring gasket will prevent sudden changes in the profile section at the bend points.
You can cold bend at home:
- manually using simple devices such as bending plates, vices and mandrels;
- using a mobile profile bender - an improved analogue of a manual pipe bender. The profile bender is different from the bending device round pipes only the shape of the recess of the working roller;
- by rolling on a home-made or factory-made profile bending machine, which you can make yourself or purchase ready-made.
It is wiser and more profitable to rent technical means of bending mechanization if they are needed for a one-time construction of a greenhouse. If you plan to build green houses for relatives and neighbors or erect a beautiful metal fence, for example, there is a reason to acquire your own bending installation.
Bending fixtures and machines
The family of bending devices and units includes representatives of varying degrees of technical complexity. First, let's look at the tools for those who are puzzled by the question of how and with what help you can bend a profile pipe without the use of special equipment. Then we'll move on to homemade rolling rigs.
Options for simple devices
The use of elementary “helpers” for cold deformation regulates the dimensions of the material:
- thin pipes with a profile height of up to 10 mm are bent using a horizontal plate with holes. Metal pins are rigidly installed in the holes, acting as stops. Bend the product by placing it between stops installed in the holes according to the bending radius. Start from the middle of the workpiece and gradually move towards the edges. The disadvantages of the method are the application of considerable muscle effort and the rather low accuracy of deformation;
- pipes with a profile height of up to 25 mm are bent using roller devices operating on the principle of a Volnov machine. Metal blank is firmly fixed in a vice, and physical force is applied to the workpiece through a roller. Bending is performed better and more uniformly than in the previous case. But by analogy, considerable effort will be required from the performer.
To form a bend with a large radius of curvature, such as arcs for an arched frame, stationary round templates with clamps are used to fix the workpiece. These devices belong to the category of plane-parallel plates. The workpiece is forcefully “placed” into a groove whose dimensions are equal to the dimensions of the pipe. The pipe, bent manually using a mandrel, takes the shape of a given contour.
Upgraded bending plate
If a home mechanic is not deprived of physical strength, he will need it for his own needs. the simplest tool for rather labor-intensive deformation of the profile pipe. It can be made in the form of a panel attached with clamps to a desktop or workbench. In the case shown in the photo, the bending plate is welded to a metal pedestal, but it is screwed with four bolts to concrete floor workshop. To remove the device upon completion of work, it will be enough to unscrew the bolts. After dismantling, no fastening pins remain and do not rise above the floor surface, which means that nothing will interfere with movement and create traumatic threats.
The principle of manufacturing a working plane is extremely simple:
- The bending plate is a panel cut from thick sheet iron.
- The panel is welded to a profile pipe, installed according to telescopic rules in the pedestal stand.
- Two holes were drilled in the working plane for bolts, which act as stops.
- The bending radius is adjusted by installing nozzles of a suitable size on one of the bolts.
- In order to maintain the alignment of the segments adjacent to the bend, a metal plate, fixed with bolts.
The pedestal is multifunctional. Its owner has the opportunity to use it as a miniature workbench to perform an impressive number of plumbing operations.
Mandrel for bending profile pipes
The method is suitable for products with a wall height of up to 25mm. The master will need a large workbench and a significant amount of free space around working area. One edge of the workbench is perforated with frequently spaced holes for fastening the mandrel and for selecting the optimal position of the part fixing the pipe. A template for the upcoming plastic deformation is cut out of thick plywood. True, the plywood mandrel is suitable only for one-time bending procedures. If there is a lot of bending work to be done, it is better to weld the mandrels from angle steel.
Using a manual profile bender
Significant volumes of deformation work require mechanization. Mass production of curved parts will take too much health from the performer. To make bending easier, it is advisable to make a machine according to the drawing. They are used mainly for working with large-sized workpieces. The main working parts of the manual unit are three rolls, two of which are fixedly fixed. Changing the position of the third movable roll determines the bending angle.
If the methods described above are not acceptable, then the future owner of the greenhouse has two options - rent manual installation or ordering the production of rounded parts. The process of deforming the workpiece was demonstrated in a video: it is up to the performer to decide how easier it is to bend a profile pipe - by repeated rolling or by physical impact.
When working manually, it is important to follow the rules for bending profile pipes and not make sudden movements. It is necessary to monitor the uniformity of deformation on the outer and inner sides of the rolled product. However, you should not be too upset about small wrinkles on the inner surface of the fold: they can be corrected with hammer blows. Before starting work, you need to make templates from wire, chipboard or gypsum board to verify and obtain a result that corresponds to the project.
