Crafts from iron beer cans. What can be done from the keys of beer cans. Decorative planters for the garden

It's incredibly simple and inexpensive. solar collector for additional home heating, which heats the air directly. The most interesting thing is that the solar panel is almost entirely made of empty aluminum cans!
The body for the solar collector is made of wood (plywood 15mm) and its front panel is Plexiglas/Polycarbonate (you can also use normal glass), 3mm thick. On the back of the body, glass wool or foam (20mm) is installed as insulation . Solar receiver made from empty cans of beer or other beverages that are painted with a high temperature resistant matt black paint. ().

When it is sunny, regardless of the outside temperature, the air in the cans heats up very quickly. The fan returns the air back to the heated air and the room is warm.
To begin with, we collected empty jars from which we will make solar panels. We must wash the jars as soon as they begin to spread odors. Attention! Jars are usually made of aluminum, but there are also some made of iron. Jars can be checked with a magnet.

A punch (or nail) is inserted into the bottom of each jar and neat holes are made, although you can drill it with a drill. The caliper is then inserted and distorted according to the pattern (Figure 1, 2 and 3). Instead, you can use special tools or large Phillips screwdrivers.
The top of the jar is cut with scissors and bent to form a "fin". Its mission is to promote turbulent airflow in order to collect as much heat as possible from the heated can wall. ( Please follow the technology!) All this must be done before gluing the cans.

Remove grease and dirt from the surface of the can. Any synthetic degreaser will work well enough for this purpose. Degreasing should only be carried out outdoors or in a well-ventilated area.. The adhesive or silicone tape on the jar is resistant to high temperatures up to at least 200°C. There are also bonding products that can withstand up to 280°C or 300°C. glue. A detailed section of the glued cans can be seen in Figure 4, and the series is shown in Figure 5.

In order not to miss with the vertical-horizontal, it is better to make a template in advance from two boards knocked down with nails at an angle of 90 degrees. The template (picture 6) will provide support during the drying of the cans in order to obtain a straight tube - a solar tunnel. Figures 7, 8 and 9 show the process of gluing and joining. be fixed until the glue is completely dry.

The inlet and outlet boxes are made of wood or aluminum 1 mm thick (fig. 11 and 12); the gaps in the edges are closed with adhesive tape or heat-resistant silicone. The perforated parts can be seen in figures 12 and 13, the first row of cans is glued to the lid of the suction port. To see what it looks like when all the parts are assembled and ready to paint the manifold, see picture 13. The glue dries very slowly. Be sure to let it dry for at least 24 hours.

The body of the solar collector is made of wood (fig. 14). The back of the solar box is made of plywood. To further strengthen the structure, you can make an inner wall. Insulation is applied between the sections - fiberglass or foam. The whole thing is covered with a thin plywood cover. The installation of the thermal insulation can be seen in Figure 15. Pay special attention to the insulation around the air inlet and outlet in the solar collector.
Next, you should install the "ears" (Figure 16) - fasteners with which the Collector is attached to the wall, and protect the wood with protective paint. Then an empty box must be placed on the wall and mark the place where there will be a hole for hot air to enter and cold air to exit. A pipe made of improvised material is inserted into the holes punched in the wall.

At the end of the work, the solar collector is painted black and placed in a cabinet. The top is covered with plexiglass, carefully fitted to the frame. the solar collector is shown in figure 19 and finally the installed solar collector can be seen in figure 20.
Look on YouTube how it works and how to make a solar collector.The test video is shown on a clear day. After the first 20 minutes of operation of the Collector, the air heats up to 50 degrees Celsius. If you are worried about how solar panels work in cloudy weather, in winter, you will certainly be interested in our video that shows it.
Important note: This design cannot store the thermal energy it produces. If it is cool at night, then it is better to close the Collector, otherwise the house will cool down. This can be solved in a simple way - by installing a valve or gate valve, which will reduce heat loss.

The differential thermostat controls the operation of the fan and turns on/off. This thermostat can be purchased from electronics stores. The unit has two sensors. If you set the temperature threshold correctly, the solar collector can produce on average about 1-2 kW of energy for heating. This mainly depends on how sunny the day is.

The dress rehearsal of solar collectors was done in the yard before installing the system at home. It was a sunny (see video) winter day, there were no clouds. A small cooler was used as a fan, taken from a faulty power supply to the computer. After 10 minutes of sunlight from the solar collectors, the air temperature reached 70°C!

After completing the installation of collectors on the wall of the house, when the ambient temperature is from -3 ° C, 3 m3 / min (3 cubic meters per minute) of heated air came out from the solar collector. The temperature of the heated air rose to +72 ° C. The temperature was measured using a digital thermometer. To calculate the power of the Solar Thermal Collector, we took the air flow, and the average air temperature was taken at the outlet of the unit. The calculated power that the Solar Collector gave was approximately 1950 W(watt), which is almost 3 hp. (3 hp)!

Conclusion: Considering that the results are quite satisfactory, it can be concluded that these homemade solar panels are definitely worth making. The collector can at least be used for the additional space in which you reside, and your task is to design and understand which savings can be achieved.

source: Implementation of solutions and photos - Mladen (inventor). Text, images, web design, SEO by Dr. Draško (Doctor), - Republic of Serbia.

Photo(arranged according to the numbering in the text).
Rice. 20. Solar collector assembly (hereinafter in order).

Straight to the point! Such a design, on a sunny day, even at an outdoor temperature of -20 ° C, is able to warm up the air flow to +50 ° C. How such a solar collector works and how to make it yourself, read on.

Much has been said about the efficient use of solar energy to reduce the cost of heating residential buildings. However, the wide distribution offered for sale and is constrained by high prices for industrial equipment. Most homemade designs are either unreliable or very complex and expensive. But if, under the sun's rays, not a liquid coolant, but ordinary air is heated, then the design can be significantly simplified and its cost reduced to a minimum.

Structurally, a solar collector made of metal cans is a rectangular wooden frame with an insulated back wall and a transparent top cover made of polycarbonate. Inside it, there are several thin-walled aluminum pipes painted matte black, through which air is pumped.

Air for supply to the collector is taken from the lower part of the heated premises and then rises up through the heated tubes. A pressure difference between cold and hot air is created, which creates forced draft. This thrust is enough for the hot air flow to enter the room through the ventilation duct, replacing the cold one.

Option with forced ventilation by means of an electric turbine

In this version, the design can be used in the supply system of mechanical ventilation.

The fan is switched on by the thermostat when the temperature sensor signals to it that the air is sufficiently heated. If the air temperature is below the set temperature, the system does not work, thereby preventing the circulation of cold coolant.

When working together with a heat exchanger, it will provide a normal temperature of fresh supply air without turning on the system air heater and save a significant amount of electricity.

Advantages and disadvantages

The main advantage of a solar collector made of metal beer cans is the low cost of the materials used and the possibility of self-manufacturing, even for a person who does not have great plumbing and installation skills. The efficiency of this device is such that it allows you to turn off the traditional heating system at an outdoor temperature above -3 ° C, which is at least a third of the entire heating season in the middle zone. The main advantage is energy savings for heating. However, there are also disadvantages.

pros	Minuses
Low price	No industrial production
No need for maintenance	The need for a specially designed air ventilation system in the house
Ability to make your own	Direct sunlight required

How it works, real use case

You can use this design even in an apartment

Self-manufacturing of the collector

This will require recycling material such as aluminum cans of beer, cola or other drinks, four boards, plywood, polycarbonate sheet or glass, some insulation and little effort in manufacturing. As a result, you will be able to get an alternative source of heat for heating your home and reduce the cost of purchasing traditional fuel.

Beer aluminum cans fit perfectly. The material itself is not subject to corrosion (and this is important since condensation can form on the walls) and conducts heat well. The inner surface is glossy and smooth, which allows heat to be reflected inside the tube and not released to the outside.

For work you will need:

• standard metal cans from beer or other drinks;
• plywood sheet 8-10 mm thick;
• 6 boards 30 mm thick;
• polystyrene or mineral wool mats 30-50 mm thick;
• sheet of cellular polycarbonate;
• matte black paint and glue for joining metal surfaces;
• fan and ventilation pipes.

The size of plywood, polycarbonate and board sheets depends on the planned area of ​​the collector. The beer metal can has a length of 150 mm and a main diameter of 65 mm. Therefore, the internal size of a structure of 15 pipes, each of which is made up of 12 cans, will be equal to:

• filling length with glued pipes 150 x 12 = 1800 mm;
• width 65 x 15 = 975 mm (can be rounded up to 980 mm);
• the size of the intake and exhaust compartments 975 x 100 mm;
• the width of the boards depends on the thickness of the thermal insulation material with the addition of the diameter of the cans - 95 or 115 mm.

So, for such a collector you will need a sheet of plywood and polycarbonate measuring 2120 x 1140 mm. Two boards 30 mm thick, 95 or 115 mm wide, 2120 mm long and 4 - 1140 mm.

Air pipe manufacturing

To assemble the air pipes, in our case, you will need 15 x 12 = 180 metal cans, beer cans from Coca-Cola or any other drinks are suitable. To prepare them, it is necessary to maximize the size of the drain hole and punch large holes in the bottom. The best option would be to completely remove the concave bottom and top cover. This is easily done on a grinder or to punch large holes with anything sharp.

After mechanical processing, the jars should be rinsed well to remove food residues and eliminate the appearance of an unpleasant odor.

The manufacture of a single pipe is carried out using a sealant, connecting the bottom of the can with the neck. Here you need to choose a heat-resistant option, since the temperature of the air in the tubes can be 90 ° C. Sealant for fireplaces is not suitable because it is fragile and may crumble over time. But, it is important for us to maintain the tightness of the pipe, so an elastic adhesive is needed. Something silicone-based is suitable, be sure to take it with a temperature margin of at least 200 ° C.

For each pipe, 12 cans are required. A total of 15 air ducts are manufactured. To simplify the work, you can make a guide fixture from two boards, knocked down at right angles along the length. Put this structure in the most vertical position and load the cans on top with something to improve the quality of gluing.

Housing assembly, insulation and pipe installation

The frame can be made in any size, depending on the place where you will mount it. However, the longer the pipes themselves that you install in it, the longer the air will go through them at the outlet and the higher its temperature will be.

A wooden box is assembled from 4 boards and a plywood or OSB sheet. Its bottom must be covered with foam or mineral wool mat. The insulation is fixed with glue.

To install the cans inside the case, it is necessary to make two holders from the boards. To do this, they drill 15 holes with a diameter slightly smaller than the main size of the can. In this case, the neck and bottom are inserted into the holes and the air ducts are securely fixed.

Installation of pipes from cans

To increase efficiency absorption of solar energy, the surface of the cans should be paint matte black(here you can use car primer, it adheres perfectly to the material and has a matte surface structure. It is also recommended to paint the wooden case to increase the durability of the structure. The top of the collector is closed with a sheet of polycarbonate or glass. The second option requires caution when working, but its surface will not fade over time and is much cheaper.

Two holes are drilled in the back or side wall of the box for connecting the supply air ducts. Their surface should be covered with a layer of thermal insulation to reduce heat loss. Already cooled air from the room is supplied to the lower part of the collector, and heated air is supplied through the upper compartment.

The manufactured heater can be installed on the southern wall of the building or on the roof slope. The thermal performance of such a device depends on its size and in each case can be selected individually.

Detailed video instruction on how to make it

I did not lose heart, and decided to proceed with the backup plan "B". In particular, use aluminum beer cans as a solar collector housing and silicone sealant as a sealing and connecting material. Both for cans and for silicone, the temperature of 60-70 degrees (at which the PET-bottle solar collector collapsed) is just seeds.

I collected cans with the help of myself, friends and neighbors pretty quickly. I had about 50 one-liter beer cans at my disposal, I decided to use 40 pcs (so as not to remake the solar collector housing from bottles.) In principle, the capacity of the water heater remained the same - about 40 liters, and the area of ​​​​the irradiated surface was about 0.6 square meters.

4 cans had to be opened not as usual, by pulling the lever on the lid, but with the help of a can opener from the bottom side, so that the “lid” remained intact. For the rest, I cut out both the bottom and the lid with a can opener, turning the cans into pipes. In addition, those 8 cans that will be at the end of the solar collector had to cut narrow holes in the side so that water could freely fill the “pipes” of the solar collector. And in one bank there is a hole for a fitting to which a hose is attached.

Council number 1. Before you start gluing the cans, you should test the silicone sealant for adhesion to the cans! It turned out that not all silicone is equally sticky. Among my “collapses” I came across a couple of tubes with some kind of silicone made in Estonia (Olympus, it seems) - it just peeled off a jar with a fingernail and peeled off completely. Silicone brand "Krass" - sticks well. Of course, the banks are all degreased before gluing.

I glued cans into such a block for the first time in my life ... Therefore, I took a pipe, “strung” 8 cans on it and began to glue the joints ... Since the silicone hardens for about a day, the structure constantly moved when lubricating neighboring cans. In general, I was in a hurry and as a result, during the check, many leaks were revealed in the block, which then had to be identified and eliminated.

Council number 2. Do not hurry! Summer has already passed, and autumn and winter will be long ... Therefore, I would recommend the following technology for assembling a solar collector from aluminum cans, if I could do it now. We take a plane (plywood, chipboard, countertop, board, etc.) We fix the “first” jar on it in any way (hot glue, adhesive tape, clamp ...). After lubricating the joint with silicone, we attach a second jar to it from the end and another one from the side. We leave for a day. The next day, we glue the next 3-4 cans, etc. So you can get a perfectly flat and sealed solar collector. Those. the main thing is not to rush!

Finally, I assembled my 4 pipes into a single block, checked it for leaks and put it in the “coffin” of the bottle collector, i.e. in a box of boards, at the bottom of which lies a piece of polystyrene foam (50 mm) covered with foil. I connected a hose to the fitting to fill the solar water heater with cold water and drain it with heated water. The block of cans was positioned so that the fitting would be at the lowest point of the box. And in the jar that was above all, he pierced a small hole for the exit and entry of air.

Having once again checked the block of cans for leaks, I painted the cans with black matte paint, and closed the box with glass. The gaps between the panes were sealed with tape. The solar collector itself is oriented strictly to the east, with a slope of about 15-20 degrees. Not the most optimal orientation, of course, but that's how the roof is located. In the end, this is just a practical experiment, laboratory work. In reality, the sun began to illuminate the solar collector from about 9-30 in the morning and went almost to the “zero” angle at 17 hours.

Since the second decade of August has already begun, I did not expect any outstanding results from this water heater. And the weather is no longer like early July. But nevertheless, these results have more than satisfied me.

Below are graphs showing my non-systematic observations. Graphs of the same color mean temperature marks of one day. Lower - air temperature, upper - water temperature in the solar collector water heater. The comments on the various charts are as follows:

- color black - almost continuous cloudiness, but not cumulus. The sun barely shines through, you can determine its position.

- sea wave color - partly cloudy with dense clouds, haze, rare breaks in the clouds.

- the color is red - almost clear, the air is transparent, in the afternoon there was about 10% cloudiness.

- color lilac - constant haze, cloudiness 5-10%.

- green color - dense cloudiness during the day from 50 to 100%.

- color blue - cloudiness 5-10%, constant haze.

At about 5 pm, the water from the solar water heater is drained into a thermos (a plastic barrel insulated with polystyrene foam) and used for household needs, watering, bathing, etc. In general, I am more than satisfied with the results, you can start building a serious solar collector. But this water heater continues to work properly.

As you can see, even on almost cloudy days, a solar water heater somehow warms up the water. And you must admit, there is a difference for the same wash - it is one thing to heat 20-30 of water or simply add one “kettle” of hot water to the already heated water to bring the water to condition. Or warm water for irrigation, for example. Cucumbers should not be watered with cold water. And what to do in dry cloudy weather? Do not heat it especially for cucumbers.

A bit of economics. As you can see from the graphs, in the morning the water "starts" at about 15 degrees Celsius. And in the evening it heats up to 55 (on a sunny day and above). Those. 40 liters of water are heated by 40 degrees. Since the heat capacity of water is 4200 J * kg * deg, water receives heat 40 x 40 x 4200 = 6,720,000 J of heat. Or 1.87 kWh (if converted into electrical power). Is it a lot or a little? 1.87 kWh of electricity cost about 4 rubles. Those. solar heater saves me 4 rubles of electricity per day. If during the season I use his “services” 100 times (and this is realistic in the period from mid-April to mid-September - 150-160 days), then the savings will be 400 rubles.

It took me about 2 tubes of silicone to make the solar water heater itself (if I had made the collector right away, it would have taken much less silicone). Banks are waste, the rest is waste material ... Well, let the costs amount to 300 rubles. But anyway - the payback of a solar collector is less than one season!

Three simple rules will help you avoid health problems, avoid cuts and get a beautiful result after all your efforts:

• Gloves for hands will save from small and large cuts.
• The container must be thoroughly washed, dried, in other words, prepared for work so that the smell of food from them is not heard.
• It is recommended to use spray cans for uniform application of paint on the surface of the can.

The preparatory work is done, and you can get to work. Of course, the simplest thing that comes to mind is to make cheerful multi-colored flower pots for your winter garden. Let the brightness of colors give a cheerful mood.

Funny flower pots

The most enterprising housewives have long thought of using tin cans for growing seedlings. But this is not the limit of fantasy. If you choose jars of different heights and sizes and paint them in gold, then you will have reflections of sunbeams in the clearing of the winter garden. Such flower pots will shine like the sun even on a cloudy day. The option of multi-colored jars will create a cheerful mood in the interior of the room.

• Like any material with which decoration work begins, the jars must be wiped with alcohol or, in other words, their surface must be degreased.
• Spray paints are the best medium for painting, but acrylic paints are also quite suitable. It is convenient to apply them with a nylon brush.
• For a flower pot, be sure to make holes in the bottom. For this, a carnation and a hammer will be enough.

If you don’t like plain pots, then using construction tape on the surface, draw stripes, zigzags, different shapes. First, the surface of the jar is covered with the main background color. After it is completely dry, adhesive tape is applied and the intended pattern is drawn in a different color.

Advice: small multi-colored jars are suitable for planting cacti. Create a clearing of cacti with your own hands. For tall flowers, you can arrange cans of aluminum (out of paint).

Decorated material for vases from jars

Natural materials are also used as decor for jars for flower pots. Having decorated a jar with this material, but without holes at the bottom, you can create a beautiful vase:

• Wooden sticks of the same length are used, tied together with twine. A wooden strip is formed, which is wrapped around the surface of the can, pulled over with a ribbon from above.
• A birch bark with a beautiful braid on top can be a decoration for a vase from a jar created in an eco-style.
• The skin cut into thin strips is applied to the surface of the can with a glue gun. Leather vase looks very stylish.

Lace, beads, appliqués, fabric, burlap are used as decor for tin vases. These vases can even decorate a wedding.

Variety of organizers made from cans

Almost every housewife stores small items in empty jars. A great reason to turn them into beautiful and unusual organizers.

You can come up with a lot of ways to decorate the surface of the jar to make a beautiful organizer:

• The surface is covered with an even layer of paint and varnished on top.
• Several jars with different dimensions are assembled into a composition: a multi-level pyramid.
• The entire surface of the jar is wrapped with multi-colored woolen threads.
• You can also connect the decoration with rhinestones to the decoupage technology.
• Glued funny animal muzzles will appeal to little organizers of the educational process.
• An easy way to decorate a jar is to use fabric.

Unusual candlesticks

A sketch of the drawing is applied on the surface of the can. Using a small drill or a nail, the contour of the invented image is repeated. When a burning candle is placed in such a candlestick, the reflection of the lights through the holes will scatter throughout the room, creating a romantic mood.

Making little helpers in the kitchen

In the recipe book of every housewife there is some recipe where you need to cut a figure out of dough, cheese, vegetables. Often an ordinary glass is used for these purposes. Then, apart from the circle, nothing can be cut out. Various molds made from aluminum cans will come to the rescue.

Cans of beer, cola will go to work. Smooth strips are cut from the can. Mold templates are prepared and various figures in the form of hearts, stars, rhombuses are assembled according to them. Be sure to leave the ends overlapping so you can join them with super glue.

Decoration for a summer cottage

An unusual decoration in the country can be a musical pendant made from tin cans. It is not difficult to make such a tool:

To work, you will need different sizes of jars. 8 pieces will be enough. A circle of metal is being prepared, an ordinary rope, nails with a hammer.

• Coat each jar individually with acrylic paint. You can make everything monophonic, multi-colored ones will look more interesting. Make one hole at the bottom of all jars.
• Through this hole, a rope is threaded into each jar, for all of the same length. The end that will be inside the jar is tied into a knot, retreating from the edge about 10 cm.
• Bells or carnations or keys are tied to this free tip.
• Prepared musical instruments are tied to a metal circle.
• An unusual decoration can be hung on a tree in the garden or on the veranda near the door.

Using glass jars

From small glass jars (from baby food) you can assemble a set for spices. It is enough to remove the labels from the jars and decorate the lids. Inscriptions with the names of spices can be beautifully written on the lids.

From the same jars, you can make a convenient organizer for various household trifles, if you screw the lids of each jar with a screwdriver from the inside to the rear of the upper shelf. You can put small things in a jar, for example, buttons, and close it with a lid screwed to the shelf. Jars will not take up space on the shelf, they will hang under it. You can also hang spices, which will always be in front of your eyes now, you will not need to look for them during the cooking process.

Large jars are more suitable for storing various cereals, pasta, flour. Jar lids can be a decoration. Handles for furniture are suitable for decoration, since the choice of shapes is large.

Cosmetic jars are decorated with glitter, which is easy to put on the inside of the jar using PVA glue.

Bold experiments will allow you to create beautiful household items that will become not just ordinary things, but also an interior decoration.

Aluminum cans from beer or other drinks are an excellent material for creating a solar collector. Firstly, it is a thin metal that heats up very quickly and, as a result, quickly heats up the air. Secondly, such cans are made of aluminum, and this metal is an excellent conductor of heat. Perhaps this is the best material for a solar collector that you can get for free.

For the manufacture of the collector housing, the author used plywood 15 mm thick. And as glass, you can use plexiglass, polycarbonate or ordinary glass with a thickness of 3 mm. In order to insulate the collector, glass wool or polystyrene 20 mm thick is used. The design is assembled quite quickly and simply. This device can heat any room, be it a barn, garage or even an apartment.

Materials and tools for manufacturing:
- empty aluminum cans;
- matte paint (heat-resistant);
- silicone or heat-resistant glue;
- drill with a nozzle for cutting large holes;
- plywood;
- a board for creating a box (case);
- fasteners such as "ears" for fixing the collector to the wall;
- glass or polycarbonate;
- a small fan (it can be from a computer power supply);
- differential thermostat;
- puncher.

Collector manufacturing process:

Step one. Preparing banks
First of all, the jars need to be washed and dried well, otherwise all this “aroma” will go into the room when the collector is working. It is best to use aluminum cans, they absorb heat better. You can check what the bank is made of with a magnet, a magnet will not stick to aluminum.

Next, holes need to be made in the banks, for this it is necessary to adhere to the scheme proposed by the author. First, using a nail or other suitable object, three small holes must be punched in the marked places. Next, take a large Phillips screwdriver or a special punch and use it to make holes, as in the photo. With this scheme, the maximum efficiency of the collector will be ensured.
The upper part of the can must be cut and bent in such a way that a “fin” is formed. Thanks to it, air turbulence will form inside the collector, which will allow the air to warm up better.

Step two. We glue the cans
For gluing cans, you need to use glue that can withstand temperatures of at least 200 degrees Celsius. The cans are glued upside down to the neck, they are perfectly suited to each other in diameter. Glue must be applied evenly throughout the circle, if the tightness is broken in the collector, its performance will greatly decrease. How the banks are connected can be seen in the sectional photo.

Thus, it is necessary to form pipes of the required length from cans. In order for the pipe to be even, it is necessary to make a template from the boards, in which the structure will remain until the glue dries completely.

Step three. We collect the frame for the collector
To create the inlet and outlet parts of the box, a board was used, in which holes are drilled using a drill and a special nozzle. You can also use aluminum sheet for this purpose.

The box itself is also made of board, and plywood was used to create the bottom.

After the body is assembled, it must be insulated. For this, fiberglass or foam is suitable. From above, the insulation is covered with a thin sheet of plywood so that the banks do not have direct contact with the insulator.

Step four. Installing banks
Now the cans can be stacked in the case. They are fixed at both ends with two boards, in which holes are cut out according to the diameter of the cans. The boards are attached with glue. To make the structure stronger, you can make an inner wall.

Step five. Collector mount

To make the collector easy to install and remove, you need to install a special bracket.

Step six. Final build step
At the final stage, the collector needs to be painted. The absorber (cans) must be painted with heat-resistant matt black paint. This is necessary for maximum heating of the absorber. The case also needs to be painted to protect against moisture. Now it only remains to glaze the structure, while it is important to remember that everything must be airtight. When using polycarbonate, the sheet must be installed in such a way that it is slightly curved, this will increase its strength.