The creation of a bend in a profile pipe by a professional builder or an ordinary owner can often occur during the construction or repair of any country house and a cottage. Deciding to bend a profile pipe with my own hands V living conditions, the owner is always puzzled by how to properly and reliably arrange a greenhouse structure, covered terrace or smoking room.

When creating such structures, these products are used, since they are much more popular in comparison to pipes with a traditional round shape.

Pipes with an ordinary cross-section in the form of a circle are bent using a conventional hydraulic pipe bender with special shoes and rollers for round workpieces. At the same time, it is not possible to bend profile parts on such a machine, since its actuators for round shapes will simply ruin the profile - the workpiece will crack, break, or be completely crushed.

Methods for bending profile elements

You can bend a profile pipe without any defects with your own hands. There are many techniques for producing such bent profile parts. One of the common options is to bend a profile workpiece using special devices - so-called profile benders. However, the price of such equipment is quite high, which calls into question the purchase of such a special machine from an ordinary owner.

how to bend a profile pipe without a pipe bender

In case of a rare need to manufacture bent profiles at home, it is suggested to purchase special pipe benders on the market for self made, used both for pipes with a round cross-section and for profile blanks. The cost of such home equipment is approximately $100. It is worth noting that when using hand tools to create bent parts, the owner must have appropriate physical and mental preparation - the work requires endurance and patience, but sparingly.

If there is a one-time need to make bends on workpieces, it is irrational to buy even manual mechanisms. In this case, it is recommended to purchase an already manufactured element on the market, or you can place an order in a workshop or at an appropriate enterprise, where for a relatively low fee they can produce any part from their own profile material.

With this solution to the problem, you can not only reduce the cost of work and not waste personal time and effort, but also achieve the desired result - get a part with a high-quality and correct bend of a certain diameter or shape.

In every construction and other business there are always traditional methods. Bending profile blanks with your own hands is no exception. Only in this case is it possible to produce bends of small-sized copper or polymer pipe blanks.

Bending profile products using a pipe bender

Process specifics

In case self-made When bending a profile workpiece, you must first determine the size of its cross-section, the thickness of the walls, the material from which the part is made, as well as the diameter or shape of the bend.

At the same time, it is also necessary to take into account the conditions of the existing production, which can ensure maximum bending accuracy and high quality manufactured parts.

Bending of profile pipes occurs within certain technical tolerances for wall thickness and cross-sectional configuration. An important task is to prevent such defective phenomena as fractures of the internal part of the bent profile workpiece and crushing of the transverse part of the workpiece.

Making a bend

In order to make a bend, it is necessary to have a special pipe bender designed for cold bending with stretching. The tension created by such a machine will shift the neutral axis of the workpiece towards bending. This effect when stretching the profile part will make it possible to reduce the formation of a corrugated zone on the bending surface.

Once located in the unit, the workpiece is clamped at the edges and at the same time stretched. At the same time, when the bending template is moved, the pipe begins to bend.

To bend a stainless steel workpiece without defects, deterioration in quality and reduction in the durability of the walls of the part in the bending zone, this process must be performed under internal hydrostatic pressure. To do this, it is necessary to plug the ends of the pipe with plugs, inside of which there is filled liquid. Next, you need to move the bendable template to the center of the product, through which a bend of a certain shape or diameter is made.

DIY bending process

You can bend a profile blank with your own hands without any professional equipment and special tools. In this way, most often it is possible to achieve a bend that is actually of relatively good quality.

Forming a bend using a regular grinder and welding

To bend a profile pipe, the first thing you need to do is have an ordinary grinder and a welding machine.

In order to bend the workpiece, you must go through the following steps:

1. Determine the bending radius of the workpiece.
2. Along the bending line of the profile part you need to make cross sections three planes with equal intervals between each other.
3. Further, without special labor you can bend the part.
4. Then you need to weld the cut areas.
5. Welding seams must be processed and ground.

Bending with internal countermeasures

To implement this technology, it is necessary to use a means such as a specially prepared spring. In this case, it is necessary to insert a rectangular spring made of metal wire with a thickness of 1 to 4 mm inside the profile pipe, depending on the size of the pipe being bent. Next, you can begin to bend the element.

The size of the spring segment segments should be smaller internal dimensions pipe cross-section by 1.5–2 mm, to allow the spring to penetrate inside the pipe without much effort.

After inserting the spring to the place of planned bending of the workpiece, before bending it is necessary to heat the bending area blowtorch. After this, you can bend the product using a special blank with a radius that must coincide with the required internal radius of the part to be bent.

For the purpose of bending a profile part for heating or water supply from copper, there is one relatively extraordinary method, feasible only in winter.

It is as follows unique option in the following:

1. First thing you need is one edge copper pipe seal with a stopper and fill it with water.
2. Then place the workpiece with water outside in frosty weather until the water completely freezes.
3. Next, bend the pipe in accordance with a bending template of a certain radius. In this case, the pipe will bend without much effort and without distorting its cross-section.

Using the same scheme, it will be possible to bend pipes of the duralumin type, as well as from a material such as brass.

Bend without a pipe bender

You can also bend a rectangular piece without a pipe bender using well-dried and carefully sifted sand. Before bending, it is necessary to hammer a wooden wedge into one of the ends of the pipe to a depth of 10 to 20 cm. After this, fill the opposite open hole of the pipe to the edge with cleaned and dried sand and hammer a similar wedge there. Then you can begin bending the workpiece using a blank of a certain diameter, which must coincide with the planned size of the product.

In case of too sharp bends - when the radius is small, it is recommended to heat the bending area using a burner device. Thanks to the sand filled to the brim in the pipe, the cross-sectional shape of the product will be preserved.

After bending, you need to burn out one of the plugs, pour out sand from the inside and tear out the second plug.

16489 0 3

How to bend a pipe: more than 10 ways to do it yourself

Hello dear readers. Today I’ll talk about how to bend a pipe without a pipe bender and with a pipe bender, and how to bend polypropylene pipe. The topic is of considerable interest since without bent pipes it is difficult to build a greenhouse, gazebo or canopy over the porch.

Why is the correct choice of bending method important?

Incorrect cold deformation of the pipe, regardless of what material it is made of, negatively affects the strength of the walls.

In the process of bending the pipe, the wall along the outer edge is greatly stretched and the material from which it is made becomes thinner. On the inside of the pipe, if bent incorrectly, the walls become wrinkled and folds form, which negatively affect both the appearance and the strength of the product.

In order for the bending of the pipe to be carried out correctly, the walls should not be crushed, while the stretching of the material along the outside should occur evenly.

How to achieve this result?

Methods for deforming pipes without compromising their strength

The choice of pipe bending method depends on the type of production materials. Three types of pipes are commonly used: metal, metal-plastic and completely plastic.

The first two categories can be bent to the required configuration. If the question is how to bend a polypropylene pipe, use an industrial hair dryer with a special nozzle.

By placing the part on the nozzle, you can heat the plastic to a temperature close to the melting point, after which you can carefully bend it. However, when working with plastic, I recommend using corner fittings with soldered or adhesive.

How to bend a metal pipe

Let's take a closer look at each of the methods listed in the diagram.

The hydraulic pipe bender is used to work with thick-walled steel pipes, which require a lot of force to deform.

Instructions for using the tool are as follows:

• The deformable part is located between metal guides and pressure rollers;
• By hydraulically moving the pressure rollers, the bend radius and angle are set;
• the workpiece is rolled through guides and pressure rollers, resulting in the required shape.

The use of a hydraulic pipe bender, due to the selection of rollers of the required configuration, allows you to work with workpieces with a traditional round cross-section and with modifications.

To increase productivity, the hydraulic tool can be supplemented with an electric drive to the rollers. As a result, you will have to set the necessary bending parameters and monitor the work process without exerting physical effort.

A manual pipe bender is similar in design to a hydraulic modification. The main difference is that the location of the pressure rollers is determined not by a hydraulic drive, but by muscular force.

Due to design differences, a manual pipe bender is used to work with pipes with thin walls and small diameters cross section. The main advantage hand tools is an affordable price and the possibility of making it yourself.

The use of external springs is important when working with thin-walled pipes with a round cross-section of small diameter. To increase the efficiency of deformation, the metal walls in the stretching area can be additionally heated with a blowtorch.

• A special spring selected according to the cross-sectional diameter is placed on the surface of the pipe and pushed to the bend point, so that the deformation area is located approximately in the middle of the pipe;
• The area where deformation is performed on the outside is heated with a blowtorch;
• The pipe is taken by hand from both ends and gently bent with force until the required angle and radius are obtained;
• After the metal has cooled, the spring is removed.

Why do you need a spring?

Regardless of whether you use an external or internal spring, it prevents the pipe walls from deforming unevenly. That is, the pipe walls at the bend section will repeat the shape of the spring.

For this purpose, special springs are made of hard stainless steel. In order for the spring to be easily removed after use, its surface is made smooth.

The use of sand backfill is an opportunity to give the pipe a more or less uniform radius and bend angle without severe creasing of the walls.

Using sand backfill, it is possible to bend only individual sections of pipes, while at the same time it will not be possible to deform already welded structural elements of the pipeline.

The deformation instructions are as follows:

• A plug is installed at one of the ends of the pipe;
• Sand without heterogeneous inclusions is poured from the other end;
• The open end is also sealed with a cork;
• At the intended bend site, the metal is heated with a blowtorch until slightly reddened;
• Holding both ends, we bend the metal pipe against a round post until the desired angle and radius are obtained.

Methods suitable for working with plastic materials

Pipes made of metal-plastic differ from their metal counterparts in having lower wall strength due to the thinner metal. Therefore, to work with metal plastic, you can use the methods listed in the following diagram.

Let's consider the listed methods in more detail.

The use of a crossbow-type manual pipe bender allows you to set the required angle and radius of a metal-plastic pipe.

Due to the lower degree of pressure, in comparison with the hydraulic analogue, it is possible to deform a metal-plastic product without the risk of damage to the thin walls.

If you need to set a small bend radius, you need to deform the metal-plastic material gradually, moving from a large radius to a small one. Despite the fact that the workpiece will have to be rolled several times, its walls will remain intact.

The use of a steel spring is similar to that of metal pipe. But if on metal it was possible to use a spring of a larger size than the cross-sectional diameter of the pipe, then when working with metal-plastic, the size should be the same.

We bend the workpiece gradually. To make it easier to remove the spring at the end of the bend, it is advisable to lubricate the adjacent surface of the pipe with machine oil.

The use of sand backfill is practically no different from the use of backfill when working with metal. Essentially, the sand backfill acts as an internal spring, which prevents the walls from collapsing.

Since metal-plastic is more plastic than thick-walled metal product, we take the metal-plastic pipe for bending not by the ends, but closer to the deformation area.

Using wire is a type of pipe deformation using aggregate. That is, if the cross-sectional diameter is small, the pipe can be filled with wire scraps to at least 80% of the cross-sectional area. Then, holding the workpiece by the ends, carefully bend it, having first thrown it onto a round post.

The only drawback of this method is the impossibility of making a bend with a small radius, since then it will not be easy to pull out the wire.

Working with profile metal pipes

Finally, I’ll tell you how to bend square pipe made of steel, equipped with a grinder and a disk for cutting metal.

The instructions are as follows:

• At the site of the intended fold, we mark slots on the inside;
• We cut the pipe with a grinder so that the disk passes through the inner and two side sides and from the side the cuts look like small hollow triangles;
• We bend the workpiece along the cuts.

The smaller the bend radius, the larger the angle of each cut needs to be made.

Conclusion

Now you know how to bend a HDPE pipe and how to perform a similar operation with metal and metal-plastic parts. Additional details can be found by watching the video in this article.

Do you have any questions about the text? Ask them in your comments.

July 25, 2016

If you want to express gratitude, add a clarification or objection, or ask the author something - add a comment or say thank you!

Independent arrangement of a private plot may sometimes require bending a profile pipe to build a greenhouse or gazebo. Some people think that this cannot be done without a special device, but there are several methods that can cope with the task.

Nuances of pipe bending

The term “profile pipe” refers to hollow products of square, oval and rectangular shape. Their round analogues are also included in this definition, but they are used less frequently (more about the types of pipes -). Give the profile pipe curved configurations and at the same time preserve it technical specifications difficult, but doable if you do it using a special device using the hot or cold method.

In this process, the profile is affected by two forces: c inside- tension, and from the inside - compression. To balance these efforts, several nuances are used:

• When bending a pipe, you need to watch its outer wall. When heated, it expands greatly and may not withstand the load, which leads to its crack.
• It is necessary to carry out the bending slowly, then the risk of breaking will be reduced.
• After completing the process, you need to check the edges of the pipe, and if they lie in different planes, repeat the bending process to align them.
• When choosing a bending machine, you need to focus on the thickness of the pipe walls and its cross-section.
• The inner wall of the pipe after the process may resemble an accordion; this is a normal phenomenon, as contraction occurs.
• Bending a pipe must begin from the end, and not from the middle, otherwise it will be more difficult to change the profile.

Before bending, you need to practice on unnecessary pipes to prevent defects.

How to bend profile pipes by welding?

You can bend the profile pipe in a semicircle using a grinder. It is used to make several cuts along the entire pipe profile. This method is as follows:

• Secure the pipe in a clamping vice.
• Make thin cuts in the places where the pipe will bend.
• Clean the cuts from shavings and carefully bend the profile along them.
• Weld the holes formed during bending using welding machine. At small diameter pipes, you can use a soldering iron for these purposes.
• Clean and sand the formed areas of the profile bend and process them protective composition, it will protect them from corrosion.

Using it you can get a pipe of the desired radius. When choosing this method, you do not need to use a vice; the work progress is as follows:

• Fix one end of the pipe in the ground and close it with any plug.
• Fill the profile pipe with sand.
• Heat up the blowtorch. Move it near the intended bend.
• Bend the pipe, but this must be done quickly so that the metal does not have time to cool, otherwise you will not be able to bend it.

This “hot” method allows the use of water instead of sand.

Spring method of pipe bending

This method preserves the integrity of the walls of the profile pipe. Before using the method, preparatory work is carried out:

• Spring preparation . It is made from steel wire. The diameter of the latter depends on the thickness of the pipe walls. A blank is used to wind the spring square section, wire is laid around it. The outer diameter of the spring must be smaller than the inner dimension of the pipe.
• Preparing the template . Pipe bending will be carried out according to a pre-made reference workpiece.

The deformation of the profile pipe is carried out by inserting a spring into it, which will protect the material from breaking. The part is heated with a blowtorch, and when hot it is deformed to the desired diameter.

Bending profile pipes on a manual pipe bender (video)

The video below shows how to bend profile pipes with a cross-section of 25×25 mm and 20×40 mm in order to make a frame for a greenhouse from them.

The pipes come with a wall thickness of 2 mm. A homemade pipe bender is a welded structure. It consists of a base of two small rollers sandwiched between posts. In the middle of the structure rises a carriage made of corners. On their upper part there is a square platform welded into which a screw with a nut from the jack is inserted, and a removable handle is inserted onto it. A handle is also attached to the first roller, with the help of which the pipe is fed to the machine. There is a third roller inside the carriage; the deflection arrow will pass through its center.

Pipe bending process:

• Place the pipe on the two lower rollers and stretch it to the required distance, turning the first roller.
• Lower the middle roller by turning the handle.
• Pass the entire pipe to the marked mark in one direction. After rolling it will become slightly arched.
• Perform the previous step only in the other direction, lowering the middle roller lower. The pipe remains in the device and you need to return it to its original position by turning the handle on the lower roller in the opposite direction.
• Run the pipe through the pipe bender a third time. The arc of its bend will increase sharply.
• Repeat all steps for the 4th time.

As a result, you will get a rather impressive radius of deflection of the pipe, in this way you can prepare required quantity profiles.

In the next video you can clearly see how you can make and use a pipe bender with your own hands:

The described methods using sand, welding and springs are used for special cases in household. If you need to bend pipes often or plan to build a large building using them, then it is better to purchase a profile bender or make it yourself. When using a pipe bender, the process goes faster, the profile is correct without unnecessary kinks.

If you are doing the arrangement yourself in your private home or country house, at least once you have had to bend a pipe. This is especially true if you need to build a gazebo, greenhouse, for example, or something similar. Therefore, bending a profile pipe with your own hands is always necessary and important. After all, such a product is much more justified to use than “round” pipes.

And there is one nuance here. With a profile product, everything is somewhat more complicated than with a round pipe, which can be bent with a pipe bender. After all, standard pipe benders are equipped with round-shaped shoes and rollers designed for circular cross-sections. As a result of using such a machine for a profile product, defects may occur or the pipe may become flattened. There are plenty of videos with similar “effects” on the Internet.

Methods for bending profile products

What to do so as not to spoil the pipe, but to bend it with your own hands? There are several methods. The simplest is to use a special machine for profile pipes. This type of equipment is profile benders. True, such machines cost quite a lot. This is not surprising, because any professional equipment is more expensive than household equipment.

However, there is an alternative, so to speak. If you need such a machine from time to time, you can purchase a manual pipe bender, which is universally suitable for standard and profile pipes. Moreover, their cost is relatively low. However, you should be prepared for big physical activity, if bending is done “manually”.

If you need to bend the pipe once, then there is probably no point in buying equipment. In this case, it is more advisable to contact specialists. It will cost much less. In addition, from such craftsmen you can sometimes purchase a ready-made product that will have the desired shape.

There is another option for how to bend a pipe without a pipe bender - “ folk remedies" However, this method is often effective for small sections. These can be polymer, copper or steel products.

Features of bending with a pipe bender

How to bend such a product with your own hands? Bending can be done taking into account the material, the required bending radius, cross-section size and wall thickness. In addition, the required level of quality should be taken into account. finished product.

Of course, there is no point in making drawings and diagrams, but bending can only be done within tolerance, taking into account the size of the section and the thickness of the walls. You should also prevent flattening of the cross section, as well as the appearance of kinks on the inside of the pipe.

Bending process

To make a bend, we need a pipe bender. It is performed using cold stretching. With this approach, tension causes a displacement in the direction of bending of the neutral axis of the pipe. As a result, the corrugated surface on the bend is virtually eliminated. There are various similar machines created according to individual drawings. However, the scheme of work is approximately the same for everyone.

When the pipe is placed into the device, it is clamped around the edges. Then it stretches and bends at the same time.

What can be done to ensure that bending takes place without reducing the quality of the product? To do this, the process takes place under internal hydrostatic pressure. Liquid is supplied inside the pipes, and plugs are put on the ends. Next, a bending template is fed to the middle of the product. It gives the pipe the desired shape.

Bending by welding and grinder

It is possible to do bending with your own hands, without a pipe bender or other device, and you can get good quality.

Alternatively, you can use welding and a grinder. Let's consider the method in more detail. First, the bend radius is calculated. Next, cuts are made evenly on three sides. Then the product is bent, and the sawn areas are welded. The welding area must be treated.

So in a simple way you can get a profile pipe of the required shape, and, as you can see, minimal tools are needed.

What to choose?

1 Type of machine is designed for radius bending of profile pipes.

Characteristics of a standard machine:

Maximum cross section pipes - 40 x40x2, 50x25x2 mm.

Minimum circle diameters:

• 30x30x2 - 650 mm,
• 40x20x2 - 650 mm,
• 40x40x2 - 1800 mm,
• 50x25x2 - 800 mm.

Drive type: manual.

Hardened rollers – all 3 pcs.

Price: 25,000 rubles.

2 Type of machine is designed for radius bending of profile pipes, round pipe and stripes.

Characteristics universal machine :

The maximum pipe cross-section is 40x40x2, 50x25x2 mm.

The maximum cross-section of a round pipe is 32x2.8 mm.

Strip 40x4 mm.

Minimum diameters of a circle of profile pipes:

• 20x20x2, 25x25x2, 15x15x1.5 –560 mm
• 30x30x2 - 650 mm,
• 40x20x2 - 650 mm,
• 40x40x2 - 1800 mm,
• 50x25x2 - 800 mm.

The maximum arc diameter is unlimited.

Drive type: manual.

Hardened rollers – all 3 pcs.

Price: 30,000 rubles.

At the Customer's request, for an additional fee, the machine is equipped with a dial indicator for the production of more accurate all subsequent workpieces.

For an additional fee, the machine can be equipped with a 220-380V electric drive

2 year warranty

Contacts:

Tel: 8-919-831-25-14

Saratov region Engels

Delivery within the Russian Federation.

Today there are many options for implementing this task. How to make a bend in your specific case? You should be guided by what your conditions and requirements are. If you need to do this one time, then you can do it yourself. If there is no desire, you can give it to a specialist. If such actions need to be performed frequently in the future, you should think about purchasing equipment - a professional pipe bender.

When the greenhouse frame is made of rolled pipes with a square or rectangular cross-section, it is very reliable and its service life is quite long. In this article we will talk about how to bend a profile pipe in order to arched design for your greenhouse it turned out to be correct, reliable, and inexpensive.

Due to the fact that the metal structure is much thinner compared to wood, there is more natural light in the greenhouse. This material is also more technologically advanced. When constructing an arched greenhouse, the profile needs to be bent. It bends for the arch that goes vertical way from the base up, and in the middle, in an arched manner. For example, if you choose a Mitlider greenhouse, the strength of the frame will be ensured by connecting the posts and beams. In dome-shaped greenhouses, the structures consist of polygonal frames (aluminium/metal), but they are quite difficult to assemble on your own.

Himself frame material is selected “for the design” of the entire structure and its dimensions. If you are going to build an arched greenhouse, the frame of which is made of metal rather than plasterboard, prepare:

• flexible rods (for half-arches) - one and a half meters long, in the amount of 12 pieces;
• for a building 1.8 m high - 10 pieces of rods, the length of which is 2 meters and the diameter is 30 millimeters;
• To make a frame, you must begin by identifying the holes for the rods; sometimes you need to bend a square pipe, in which the cross-section is 20 by 20 and the diameter will be three meters.

You will need these tools:

• bending machine;
• profile pipes;
• tape measure, simple pencil;
• Bulgarian;
• welding.

You can make a bending machine yourself; you actually need to bend the profile pipe on it. Scroll it with the handle. It will take a lot of effort, even when the wall thickness of the material is about two millimeters, because it’s not like folding drywall! If you don’t have a machine, you can bend it with your hands. Secure the pipes running parallel. Draw an arc of the required radius directly on the ground, attach the product and bend it so that it becomes exactly the same as in the drawing. The next arc must be bent according to the pattern of the first.

The pipe must be cut into equal parts in advance using a grinder, and then bent according to the sample. In those places where there were undercuts, treat with spot welding. The light and strong profile is quite easy to connect to the planes. In addition, it is able to withstand a fairly large lateral load.

Using a Pipe Bending Machine

Anyone who has tried to bend a profile pipe is aware that it is very difficult. It is much simpler and easier to work with drywall, but not in in this case! Here a special pipe bending machine or a manual method can come to the rescue. Also one of the ways is fire. One part of the pipe is heated, then, using a lever, it is bent at a certain angle. The disadvantages include appearance(upon completion) - rather unaesthetic and it will require a lot of physical effort, because this is not drywall!

Of course, with the help pipe bending machine You can bend the pipe much more accurately, faster and easier. Holding the handle, the profile stretches along the machine’s rollers, while the other one presses down the material, thereby deforming it. It is much more “pleasant” to bend a product in this way when it passes through a pipe bender and turns into an arch, moreover, of the radius that was given to it. Using manual machine, products can be bent to warm up the greenhouse during cold weather.

Make a pipe bender. You will need:

• 3 pieces of roller;
• special bracket with a clamping axis and a lead screw;
• metal table;
• template and blank;
• steel pipes with a diameter of 0.7-1.5 cm;
• channel and welding;
• concrete solution.

Bending methods

You can bend pipes for a greenhouse using a cold or hot method. Both options are provided. If you heat it with gas burner, ductility will be much higher. But if the pipe has a small cross-section, it is easy to bend it without impact high temperatures. Pipes with thin walls are flexible and easy to bend. There are no specific recommendations regarding heating materials, with the exception of pipes with a diameter of more than one hundred millimeters. But if the pipe is square or rectangular, you need to work with them a little differently.

If the profile height is less than ten millimeters, it must be bent cold. If the height is forty millimeters or more, then you can’t do without heating. Regarding bending material with a height of ten to forty millimeters, everyone decides for himself how it is convenient for someone and in what way, after all, it’s not drywall that needs to be bent! If you have a special device for bending the pipe, then you can do without heating.

Video “How to make a pipe bender and bend a profile pipe with it”

A lot of necessary information about a pipe bender to ultimately make a frame for a greenhouse.

Cold method

If the profile height is up to ten millimeters, it must be filled. For this you can use sand, rosin or a tightly wound spring. You can do this with your own hands, for which you will need: a bending plate, a vice and a mandrel, a bending profile (you can either make it yourself or purchase it in a store).

With heating

Material that is not amenable to the cold process must be heated at high temperatures. The pipe is first filled with sand to ensure uniform bending and quality of work. You will definitely need canvas mittens. Trimmings (logs) will be needed for a pyramid-shaped plug, ten times longer than the base. The base area of ​​the plug itself should be twice the size of the hole it will cover. Try on how the plugs fit, then make longitudinal grooves on one of them, on each side. On the future bend you need to anneal the workpiece.

Prepare a filler from construction medium-grained sand (it needs to be sifted thoroughly, several times through a sieve with mesh different diameters, first 2 mm, then 0.7 mm). Next, the filler must be heated at a temperature of 150 degrees Celsius. Plug one end of the pipe with a plug, and place a funnel on the other. The workpiece must be installed perpendicular to the ground, or at an angle, it all depends on the size. And fill it with sand through a funnel. To make it compact, tap the pipe with a mallet. A hollow sound means full.

Then close the second plug with the end of the pipe through which the sand was poured. Secure the product in a pipe clamp or vice. Welded joint should be on the side. Very carefully give the required shape to the pipe. In one step, bend it not sharply, but always in a vertical or only horizontal position. Everything worked out. The plugs can be knocked out (burnt out) and the sand poured out, the material for the greenhouse frame is ready!