How to cut polystyrene foam so it does not crumble

How to cut the extruded polystyrene foam. How to cut the foam board at home. Effective cutting foam with a string at home

Styrofoam is a fairly popular building material. It is used for thermal and acoustic insulation. In the process of construction work this material requires processing, in particular the cutting under the required parameters. There are many options for cutting Styrofoam that can be used at home.

The procedure for cutting foam requires compliance with certain rules, as the material, if handled improperly, is capable of breaking, crumbling. To perform the cutting of foam are used a variety of tools, for example, a good knife, soldering iron, saw with fine teeth for wood, metal, nichrome wire, angle grinder (only for thin Styrofoam).

Consider several ways to cut Styrofoam materials.

Cutting by string

You can make at home with your own hands a special device for processing (cutting) foam. To do this, you need to buy a step-down transformer, a string, springs, with which the string will be stretched, a pipe with a thickness of 2 cm for the lining. The thickness of the most polystyrene board, which will be cut should be not less than 2 cm.

To arrange the table top for this equipment will need a table, a profiled sheet, a board. To fabricate such a device for cutting polystyrene at home is not difficult.

What are styrofoam boards

To understand how to cut polystyrene foam, find out its structure. It consists of polystyrene granules. To make it sheet, a technique is used:

• The impact of elevated temperatures;
• cooling, which gives rise to a large volume of air inside the polystyrene;
• Pressing, in order to get the plates of the required size.

The result is a material that is 98% air, only 2%. from solid structures.

The board is obtained as a result of pressing, after which the product must be cut into sheets of desired length, width and height.

House insulation

Areas of application. where foam plastic is used

Conventional or extruded polystyrene foam is used in the following areas:

• insulation of floors, walls, ceilings and roofs, which prevents the escape of heat and the passage of cold;
• foundation insulation;
• Erection of permanent formwork;
• pipe insulation.

It is not uncommon to use in other areas as well. For example, making furniture, building ships, or making handicrafts for the garden or school.

Decorative slicing

What and how to cut foam boards?

Sheet foam is an insulation made of expanded polystyrene. It is also called expanded polystyrene. It is one of the most popular house insulation materials, since it is inexpensive and easy to install. But during the installation of the boards it is often necessary to cut them. It is extremely important to make the cut of the foam sheet even, as large gaps can impair the thermal insulation performance.

Cut polystyrene foam at home you can use many methods:

• with a knife;
• hacksaw;
• with a jigsaw;
• With an angle grinder;
• electric knife;
• A styrofoam cutting machine with a wire.

A sharp knife is good for slabs up to 5 cm thick. The blade should be thin and not flexible, as otherwise the cut will be crooked. To cut foam plastic with your own hands to be even less waste, it is better to heat the knife. Keep in mind that the blade must be resharpened every 2 meters or so, as otherwise the work will take longer and there will be more debris.

Jigsaw and angle grinder can also be cut at home, and boards with greater thickness. The most important thing is that the height of the blade or disc is sufficient. The jigsaw should be moved smoothly, otherwise the styrofoam balls will start to peel off from each other. Keep in mind that during sawing with these methods the foam is very crumbly.

For cutting expanded polystyrene boards up to 10 cm thick a hacksaw for metal or wood is a good choice. The shallower its teeth are, the better the cut will be. In addition, this sawing method is fast and does not require any great effort. Act smoothly and evenly, without sudden movements.

To prevent the foam crumbles and the cut is even, you can use a wire with a cross section of 0.5 mm and stretch it between the two handles. Start sawing by the marking and at the same speed. The wire will heat up and melt the foam because of the constant friction. This cutting method makes the edges of the board smooth and flat, and the amount of waste is minimal. The only disadvantage is that it requires two people.

If you plan to cut a large number of foam boards it is better to buy a soldering iron attachment or a special electric knife. The sharp blade and high temperature cause the boards to cut quickly and smoothly. They are also used to make shaped cuts. But it should be borne in mind that the length of the blades of many tools is no more than 5 cm. Also, when working with hot tools, you should be careful not to get melted foam on your clothes or skin. It is not possible to remove it from the skin instantly, which means a severe burn.

Another good device that can be used to cut foam boards is a special machine. It can be purchased or made by hand. Cutting is quick, quiet and effortless and material of all thicknesses can be cut (depending on machine capabilities). The amount of waste is minimal and the cut is absolutely flat and smooth. Another advantage of this method, thanks to the hot nichrome wire, the cut cells are melted back. As a result, the thermal insulation characteristics of the foam do not deteriorate.

Tips and tricks and how to make your own simple machine

Before you cut the foam plastic, you need to make a marking with a sharp pencil. If possible, cut the slab in the direction away from yourself. During the sawing of foam plastic by heating method (with a machine with a wire, an electric knife) emits dangerous black smoke, which is very harmful to humans. That is why it should only be cut with these methods in a well-ventilated room or outdoors.

In order to make a simple machine, you need a surface with a slope (20-60 °). Across it is stretched nichrome wire with the desired height of cut. One end of it is firmly fixed, and the other is connected to the spring. Then you need to lead the wires from the power supply. The amperage must be controlled so that the wire does not overheat too much, so a rheostat is additionally connected. The temperature should not exceed 100 ° C. After everything is ready and the strings are heated, the foam is cut. To do this, just put the plate, and it starts to roll itself (if the surface is smooth enough) or it is pulled evenly through the wire. If you do it too slowly, the cut will be wide, because during this time will have time to melt a lot of foam. If fast, there is a risk of tearing the string.

Ready-made machines for cutting polystyrene foam have more options. They are used to make 3D figures. Depending on the equipment, they can have from one to six strings. They are controlled either by the operator manually or through a computer program. Some have compact size, as a result they are easy to transport, which is extremely important for builders. There are also models with a laser. these devices make the best cuts. Laser machines are used to cut out shapes for storefronts, trade shows, or any other important events.

Tips from the Professionals

For fast and efficient cutting of Styrofoam, the following professional tips are recommended:

• It is not very convenient to cut with an ordinary knife. It is best to use a soldering iron instead. Quickly and efficiently cut foam plastic will be possible if the round side can be easily flattened with a hammer. In addition, you must put a metal cap on the electrical device. The blade should be well secured. Only then should the soldering iron be plugged in. Work with the tool only in a well ventilated area. It is best to additionally open the windows. The soldering iron emits gas when heated, which has poisonous effects on the respiratory system.
• It is most convenient to cut the foam with a nichrome thread. It will make the process quick and the edges will be straight.
• Nichrome material is found in hair styling appliances, hair dryers, irons, boilers. If it is not possible to get such a thread, you can use steel wire. It should be stretched across the table. One side is fixed rigidly and the other side only with a spring. A transformer is connected to both of them. It should be plugged in beforehand.
• The foam sheet must be placed on top of the wire. The current charge depends directly on the thickness of the working material. It is necessary to make the wire become red. Do not let it glow, because then the cut may be too wide.
• All manipulations are most convenient to perform in the case, if the table will be at an angle of 20-60 degrees to the floor. This ensures that the foam itself is fed by its own weight. However, there must be a sufficient level of slip for this.
• The nichrome wire will become larger during operation. This is why it is important to secure it to one side with a spring. Thanks to it will adjust the length.
• To cut the foam material it is allowed to use an angle grinder or an electric jigsaw. It is also recommended to use a saw with a wavy blade.
• If it is necessary to create foam figures, then the dough molds are quite suitable for cutting them out. However, in this case, you can take only the foam plastic, the thickness of which does not exceed 1.27 cm.
• To quickly smooth out the protrusions, you just need to rub the foam material against each other.
• When working with foam plastic it is recommended to perform all manipulations on the cutting board. In this case the probability of damaging the table is minimized.

Nowadays, foam figures are very popular in interior decoration. For their creation it is advisable to use a special knife or automatic device. To get an even edge, it is advisable to perform all manipulations with a preheated object. The knife can be made yourself from an old soldering iron. This tool is very popular with interior designers.

If you decide what to cut the foam plastic at home so that it does not crumble, you can use the simplest homemade tool. a strong thin string with wire tied to the ends of the handles. For sawing you will need an assistant who will pull the second handle. The work itself resembles sawing wood with a two-handled saw, but the material is not cut, but rather rubbed and melted under the metal being heated from friction.

Tools for thermal cutting

Styrofoam is not just an insulator. It is used for elements of interior design: skirting boards, moldings, imitations of columns, etc.д. This material is also appreciated by decorators, cutting out from a light and plastic mass a variety of figures, letters, frames.

Styrofoam Christmas decor Source toppennewyear.ru

Professional device for cutting foam by yourself

If the amount of work is larger and shape processing is required, then you should pay attention to professional equipment. Specialists use a soldering iron with a knife nozzle. The heated blade helps create any cut.

Safety precautions must be taken during operation to prevent hot oil from getting on your body or clothing.

Homemade equipment with nichrome thread can be used at home.

The method has already shown its effectiveness and convenience. There is not much waste. The edges are sealed, and the material does not lose its properties.

Necessary materials for creating a homemade tool:

The needle is fixed on the table and the thread is stretched between its ends.

Then connect the elements in series. The thread should only turn slightly red while it is being energized. Too hot thread will provoke an uneven and wide cut.

If you plan to do a large amount of work, it is better to buy a special tool in the store. It heats up quickly and guarantees the quality of the work. But it has a high cost.

If you are going to cut foam seldom, it is not worth buying a professional tool to cut it

Cutting foam has some features at home. So on the preparation is required to make an accurate marking with a sharp pencil.

When working, you should cut the material from yourself to the side. Cutting should be done in a well ventilated room or outdoors. When heated, the foam plastic begins to release toxic substances.

Application and advantages of foam

Styrofoam is used in construction, it is used to insulate roofs, walls, foundations, and other structural elements. Various decorative elements can be cut from such material.

Styrofoam has a number of advantages:

• This material has low sound conductivity, and serves as an excellent insulator, retains heat, thereby saving heating costs.
• The foam is resistant to moisture, so no fungus or mildew.
• Foam is a light material, so it is not difficult to work with it. It is durable, since it does not age and does not decay as a result of damp.
• The material is resistant to temperature changes, so it is used for both external and internal works. From it you can perform a variety of decorative elements inside and outside the room.
• Cutting foam can be done independently at home without resorting to the help of specialists. Thanks to the thermal method of cutting, you can get perfectly flat edges. This method is used to cut out various shapes or edges with exact flatness.

The technology, how to cut a sheet of foam correctly

For home conditions, you can offer a few proven ways:

Important! Whenever attempting to cut a foam sheet with hot blades, wires or high-speed tools, you must work under a hood or outdoors, as the melting of the foam releases a large amount of volatile toxic substances.

If the foam board must be cut with an electric jigsaw or angle grinder, you must use a respirator and safety glasses. When cutting foam dust, it is highly electrified and adheres with incredible force to the skin of the hands, face, eyes and lungs.

Cutting Styrofoam mechanically

The easiest way to cut a thin board, up to 50 mm, is with an ordinary, even a table knife. To do this, place the foam board on the edge of the working table and make the cut. The cutting edge of the blade should be as close as possible to the reference plane. The blade must be sharpened and adjusted on a polishing wheel before cutting.

The part of the sheet to be cut off must be supported so that it does not break off under load. To cut with maximum quality, the knife is moved with little effort in one direction. “from yourself”, the reverse stroke of the blade is performed “idly”. If you have to cut a sheet on the table top with a hacksaw, the direction of the cutting force is reversed on the table top.

Cut the thin sheet foam material on the weight or in a vertical position is strongly not recommended.

It is much easier to cut Styrofoam with a metal hacksaw. For rigid brands the blade of the hacksaw blade can be kept unchanged, for highly porous foamed sheets the sides of the blade should be ground on a sharpener to eliminate the teeth dilution. You can cut with a hacksaw in nearly any position without restriction.

The most productive tool for cutting sheets is an angle grinder or angle grinder. Depending on the diameter of the cutting wheel the angle grinder enables to cut foam plastic up to 50mm thick on the fly. The quality of the cut will be much better than with a knife or saw. The disadvantage of this method is a large amount of dust and shavings. If you reduce the cutting speed of the foam to a minimum, the material will burn and melt, which is not always allowed under the cutting conditions.

It is easy enough to cut the foam sheet with an electric jigsaw. In terms of performance and quality of cut the jigsaw is inferior to the angle grinder, but it has an invaluable advantage. with its help you can make shaped cuts that are difficult to obtain other mechanical cutting method.

Thermal methods of cutting foam

The second most common way to cut Styrofoam is with a thermal cutter. Essentially, it is a nichrome thread laid on a frame in the form of a frame. When an electric current is passed through a nichrome wire, the metal surface heats up and melts the foam plastic. There are several options for torch design. The simplest looks like a nichrome string strung on ceramic insulators mounted on the ends of a wooden or metal frame.

With such a tool, you can cut not only styrofoam sheets, but also wooden laths, plastic pipes, any material with a melting or decomposition temperature up to 270 o C.

If you want to cut a slab with a long cut length it is more convenient to use a machine in the form of a vertically stretched thread on a stand of textolite.

A LATP or rheostat is used to control the heating of the nichrome string. Too high a surface temperature can lead to melting and even ignition of the foam. The great thing about this cutting method is that it is completely free of dust and chips and also that the cut surface is melted, like an alkyd varnish.

If in the process of foam processing it is necessary to cut only small portions of the foam block, for example, in the manufacture of a sculpture or model, it is best to use the nozzle for the powerful electric soldering iron.

The most interesting way to cut Styrofoam with a laser should be mentioned separately. It may seem fantastic, even at home it is possible to laser cut Styrofoam, photo. Normal LED laser power of 2-5 W can cut a sheet of foam on an arbitrary trajectory.

While such a tool can cut paper and Styrofoam for 10-15 minutes, so a large amount of cutting on it will be very difficult to achieve.

Why is it hard to cut Styrofoam

The widespread use of expanded polystyrene was largely constrained by its porous structure, which resembles a compressed layer of tiny polystyrene cells filled with a gassing agent.

If you have ever had a chance to cut foam sheets, you have probably noticed this peculiarity:

• The denser and heavier the material, the easier it is to cut it with sharp tools. The thinner the cutting edge, the easier and faster it is to cut even the hardest urea foam;
• Lightweight foams are best cut with electric tools. The higher the cutting edge speed, the cleaner the cutting surface. In industrial settings, non-thick foam boards are cut with a thin water jet, almost without waste;
• When you try to cut the board with a sharp blade in several movements, a situation develops where each new cut almost doubles the amount of foam sawdust and dust.

Tip! Thin foam boards are cut by craftsmen with a shoemaker’s cutter. To do it with a sharp-edged wide blade with great effort make the cut with a knife “on itself” without changing the angle and depth of cut.

Most modelers and craftsmen who work professionally with foam plastic will protest that it is not at all difficult to cut foam plastic boards, especially since the density and strength of the material is relatively low. And they will be right. Cutting foam at home is not difficult, you only need to accurately select the mode and equipment for cutting foam.

The number of options for the practical application and use of foam plastic for those who know how to work with their own hands, has long exceeded a hundred. Foam material is used for making dozens of different models, molds, toys, stucco, decorative elements, insulation, acoustic system parts and even refrigerators. The main problem which accompanies any attempts to process the material mechanically is the choice of how and what to cut the foam plastic so that it does not crumble, as a consequence the cutting is always accompanied by a large amount of waste product.

If the edge of the cutting tool is not sharpened enough or moves with low speed, when trying to cut the smallest gas-filled balls the cutting edge does not cut them, but slides on the styrofoam, crumbs and tears from the compressed mass of foam. It is possible to cut foam sheets with this method, but it produces a great deal of waste.

Technology, how to properly cut a sheet of Styrofoam

For home conditions, a few proven methods can be suggested:

Important! In any attempts to cut the foam sheet with hot blades, wires or high-speed tool to work under the hood or outdoors, as the melting of foam plastic emits large amounts of volatile toxic substances.

If foam plastic is to be cut with a jigsaw or angle grinder, a respirator and safety glasses must be worn. Styrofoam dust when cutting strongly electrifies and with incredible force sticks to the skin of the hands, face, gets into the eyes and lungs.

Scheme of cutting foam board mechanically

The easiest way to cut a non-thick, up to 50 mm, board with the help of an ordinary, even a table knife. To do this, lay the foam board on the edge of the working table and make the cut. The cutting edge of the knife should be as close as possible to the supporting plane. The blade must be resharpened and adjusted on a polishing wheel before cutting.

It is necessary to support the cutted part of the sheet to avoid breaking the material under load. In order to cut with maximal quality the knife is moved with little effort in one direction. “from yourself”, the blade moves backwards “without load”. If you have to cut a sheet on the table top with a shoemaker knife, change the direction of the effort to the opposite. “toward you”.

It is strongly not recommended to cut thin sheet foam material by weight or in vertical position.

It is much easier to cut Styrofoam with a metal saw. For rigid grades the blade of the hacksaw blade may not be changed, for highly porous foam sheets the sides of the blade are ground on the grinder to remove the tooth separation. You can cut with the hacksaw in almost any position without restriction.

The most powerful tool for cutting sheets is an angle grinder or angle grinder. Depending on the diameter of the cutting wheel, the angle grinder can cut foam plastic up to 50 mm thick on the fly. At the same time the quality of the cut will be much higher than when using a knife or saw. The disadvantage of this method is a large amount of dust and shavings. If the cutting speed of the foam is reduced to a minimum, the material will burn and melt, which is not always allowed by the cutting conditions.

It is sufficient to cut the foam board with an electric jigsaw. In performance and quality of cut the jigsaw is inferior to the angle grinder, but it has an invaluable advantage. with its help you can make shaped cuts that are difficult to obtain other way of mechanical cutting.

Thermal methods of cutting foam

The second most common way to cut Styrofoam is with a thermal cutter. In essence, it is a nichrome thread laid on a frame in the form of a frame. When passing an electric current through a nichrome wire, the metal surface heats up and melts the foam. There are several design versions of the torch. The simplest looks like a nichrome string stretched on ceramic insulators mounted on the ends of a wooden or metal frame.

With such a tool, you can cut not only styrofoam sheets, but also wooden laths, plastic pipes, any material with a melting point or decomposition up to 270 o C.

If you need to cut tiles with a long cutting length, it is more convenient to use a machine in the form of a vertically stretched string on a stand of textolite.

The LATP or rheostat is used to control the heating of the nichrome wire. Too high a surface temperature can cause the foam to melt or even catch fire. The wonderful thing about this cutting method is that it is completely free of dust and chips and has a molten surface like an alkyd varnish.

If during the processing of foam it is necessary to cut only small fragments of the foam block, for example, in the manufacture of a sculpture or model, it is best to use the nozzle for a powerful electric soldering iron.

We should separately mention the most interesting way to cut the foam with a laser. It may seem fantastic, even at home it is possible to laser cut Styrofoam, photo. An ordinary LED laser with a power of 2-5 W allows you to cut a sheet of foam on an arbitrary trajectory.

While such a tool can cut paper and Styrofoam for 10-15 minutes, so a large volume of cuts on it will be very difficult to achieve.

Coloring procedure

If there are doubts about the color and adhesion of the composition to the surface, you should conduct a small test. On a small part of the styrofoam sheet you need to apply the purchased compound and leave it for two days. Then you should assess the result. In case of positive effect the coloring work can be started. Otherwise the paint will have to be replaced.

When finishing foam plastic inside the room, the composition to be painted bears a decorative orientation. The material is thus protected against moisture. Before staining the surface, make sure it is clean and free of grease stains. When cleaning the surface, make sure that the rag does not leave lint. If there is a lot of dirt, it is quite easy to clean the foam core with warm water.

The foam board can be painted only after the material has dried thoroughly. In addition, it is applied in layers. They should not be thick. To prevent streaks, it is necessary to work with the tool in one plane. Always wait until the first coat is completely dry before applying a second coat. Foam is not capable of absorbing paint, so after applying the first layer, you should look closely. and whether the second one is needed? For staining the surface of the foam plastic a good emulsion composition is suitable.

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There are no drawings and drawings, but it is most likely a cutter for foam plastic.

hi. You take a sheet of plywood to size put wooden bars in them two iron studs to one to the other. from an inverter welding between and. nichrome wire. You set it up right, and then you cut.

Look at my blog, something link does not insert. I made a torch like this.

I had a broken blade from the kitchen year, plain stainless steel. I made a shank and put it in the jigsaw, and it cuts amazingly fast.

Stitched the whole ceiling with no debris from cutting the foam.

I hooked it up to an ancient but eternal charger my dad gave me

Oh, crap. !I’ve got one just like it, and my dad gave it to me!Works like a sweetheart, but the current regulator’s been acting upif I take it apart, I’m afraid I won’t be able to find a rheostat to replace it.

I made a quick one of these

An ordinary knife or the more clerical. are very inconvenient when cutting the EPPP more than 30 mm thick (the blade jams). I cut the EPP with a homemade knife made from an ordinary metal-cutting blade. Sharpened and left teeth on the blade (serrated sharpening). You put a sharpened blade in the handle for the hand saw.

You don’t have to try to cut the EPPP very precisely, all joints will be sealed with foam afterwards anyway.

Electric jigsaw and a saw sharpened like a knife.

I cut it with a hacksaw, the stitches are still foamy. But it’s better to cut it with a nichrome spiral.

I made myself such a thing, cuts the foam with hurray, the most important thing is even and the edge does not crumble. The table is 1.5×1.2m. Cutting is regulated by self-tapping, moving the spiral on a bar up or down, the spiral is better to the bar through the washer to which clamp the wire.

You take the nichrome and hook it up to the welder. Don’t go too hard on the amperage, it’ll burn out fast. I took the nichrome from an old ballast resistor. I used this method to dissolve 100 at an angle to insulate the plinth, and on top of the sill. Good luck with cutting!