Mica burned in the microwave: what to do, how to replace it

Mica - what is it?

Mica is a natural dielectric material that transmits radio waves. There are three types: sheet, powder and intumescent.

In its natural state, the mineral crumbles. To use it as a dielectric layer, it must be applied to an elastic base - the thickness is 0.4-0.5 mm. The color of the mineral is gray-white, indeterminate.

Types of mica and its properties

Mica was not chosen by chance as a material for the protective cover of the waveguide. Among its positive properties:

transparency to ultra-high frequency radio waves;
environmental cleanliness;
low electrical conductivity;
vapor permeability;
affordable price.

In nature, mica is found in various forms, but they all crumble heavily. Therefore, in production it is applied to a flexible base, resulting in a material resembling geotextiles. Mica gaskets are cut out of it to cover the output hole of the waveguide in the working chamber of microwave ovens. They have a thickness of about 0.4-0.5 mm and can be gray, white, or have an indeterminate color. In this case, the plate must be monochromatic and have a high surface cleanliness.

Why does a microwave need a protective screen?

The “heart” of any microwave oven is a magnetron, which generates microwave waves. It communicates with the camera through a waveguide - its output is covered by a special plate similar to thick fabric. Located on the right wall. If you press with your finger, the surface behind which there is a rectangular hole in the waveguide is pressed.

If your microwave oven sparks, there is an 80% chance that the mica gasket in it has burned out. What is this flexible barrier for? Firstly, thanks to it, the microwaves emitted by the emitter are reflected. Secondly, high-quality heating of products is ensured. The gasket is located in the center, right or bottom.

Why is the waveguide separated from the chamber by mica?

The condition for normal operation of a microwave oven is the cleanliness of the waveguide walls. Otherwise, its effectiveness decreases and oxidation occurs. The main purpose of mica plates is to protect the waveguide from grease and other contaminants.

Important! You should remember about the plastic lid that covers the plates with food. If grease or other contaminants get on the protective sheet, an electrical breakdown of the dielectric may occur, due to which it will begin to burn out.

Fat that gets onto the protective sheet burns under the influence of the emitted rays. The plate is destroyed, cracks form in it, through which radiation directly enters the stove. The result is sparking and crackling. Often, in parallel with the overlay, the magnetron cap burns out and the paint burns. If signs of burnout are noticeable - the stove sparks and crackling sounds are heard, immediately turn off the power and take measures to eliminate the problem.

Attention! Experts assure that neither peeling paint nor a burnt cap will interfere with the operation of the device. But only until the magnetron antenna burns out completely.

Why is there a mica plate in the microwave?

In order for our microwave oven to produce microwaves, it has a microwave generator inside - a magnetron. Its waves enter the working chamber of the furnace through a special waveguide. It is its exit that is closed by mica. At the same time, it does not conduct electric current, since it is a dielectric, but transmits any radio waves.

What functions does the mica plate perform?

Protects the microwave generator from high temperatures during heating or cooking.
Distributes microwaves evenly inside the chamber.
Protects the magnetron from aroma molecules, steam particles, fat, food, which inevitably splash throughout the working chamber when using a microwave oven.

This is why the protective mica plate must always be kept clean. After all, moisture particles deform mica and lead to its rapid oxidation. And food debris or fat, falling on the protective mica surface, begins to burn under the influence of radiation from a microwave generator. Then the mica itself burns out, and through these small “gaps” the radiation enters directly into the furnace chamber, leading to a change in the current distribution pattern and, accordingly, to breakdowns. This is where sparks and crackles occur.

To avoid such problems, use a special plastic lid when heating or cooking food, which prevents food particles from splashing.

What you need to know about frequencies

Many people have noticed that mobile phones and Wi-Fi do not function well near a microwave oven. The reason is the coincidence of frequencies. Household appliances use only the values allocated to them - among them 2.4 GHz. Waves of this frequency are actively absorbed by water, the screen serves as an insulator of the chamber from the magnetron and waveguide.

Why aren't there microwaves that don't interfere with computers? The point is the instructions of government bodies - they are the ones who decide at what frequencies to work.

On a note! A microwave oven at a frequency of 2.4 GHz fries the chicken. How does a telephone operating at a similar frequency affect if it is constantly brought to the ear? This is why the power of mobile devices is limited.

When to replace mica

As it is used, the mica plate becomes dirty from grease and deformed from moisture and becomes unusable. It can even be colonized by fungi.

The first sign that the wall between the waveguide and the camera has burned out is a strong cracking sound when turned on . Intense sparking begins inside, and electric arcs even appear near the gasket. If you look closely, dark spots are visible on the mica. If there is an oval with a diameter of 5-6 mm, the stove begins to “perturb.”

The pad absorbs fats and aromatic molecules and becomes filled with them over time. Next, electricity penetrates the material - strong sparking is observed inside the chamber. To correct the situation, you just need to change the broken protection. How to replace a layer that has become unusable? Sheet mica is sold in specialized stores.

Important! The more careful and regular maintenance, the longer the protective gasket will last. Be sure to clean the inner walls of the chamber from food, wash the smooth parts with weak detergent solutions, and keep the plate clean.

What to do if there are sparks in the microwave chamber

If sparks are visible in the microwave oven, there may be several reasons:

The bottom of the mica sheet burned through. This is the case we are considering.
The enamel is damaged. This can happen due to surface contamination, which causes sparking.
Metal utensils. If the cymbals have a metallic finish, sparks will occur.

What is Microwave Oven Mica Plate

Mica is a layered brittle mineral - a dielectric. In a microwave oven there is a plate of this material applied to a flexible base. It protects the magnetron (powerful electron tube) from contamination. The fat deposited on this part of the unit turns into coals under the influence of heat. High-frequency electromagnetic radiation leads to the formation of an electric arc between them. Because of the latter, the mica plate melts, suffers a breakdown, and ceases to perform its protective function, without which more important parts will fail. Even if the element is only slightly melted, it is necessary to replace it. This is easy to do at home.

Remember! You cannot use a microwave without a mica plate if you want to extend its life and maintain the health of yourself and your household. Using an oven without a protective element will result in excessive exposure of the food being cooked to radio waves. It is dangerous for the health of those who use it.

There is evidence that regular consumption of such food leads to serious illnesses, such as asthma, vertigo, and seizures. Symptoms of food poisoning from a malfunctioning microwave are similar to the symptoms of nicotine poisoning.

How to replace mica

If you are convinced that the cause of the crackling and sparks is a burnt gasket, replace it. It's very simple, you don't even need to call a specialist. If a plate burns out in a microwave, you can replace it yourself. Let's look at the gasket replacement sequence using the LG model as an example:

Buy a new plate. Where can I get it? Look in stores or on the Internet.

Important! When buying a protective screen for a microwave, pay attention to the availability of certificates so that it does not cause harm to health.

Remove the heated sheet. It can be attached in different ways: with self-tapping screws, plastic latches. Depends on the microwave model.
Wash the damaged sheet from dirt - you will need it as a stencil. Cut out a new record with a sharp utility knife. The holes can be drilled with a suitable size drill or pierced with an awl.
Rub the cut sheet with sandpaper to remove any irregularities.
Dry it.
Remove grease and dirt from where the mica sheet will be located. Clean the surface thoroughly.
After removing the magnetron, inspect its protective cap. The overheated part will have to be replaced.
Burnt areas need to be cleaned with sandpaper, and the peeling enamel should be painted over with a special dye.
It's time to install a new protective screen. Mounting the plate is quite easy; it is usually attached in one of the following ways: - you need to install the sheet in a special pocket secured with a screw; — if the plate is held in place by metal tongues, it must be bent when installing.
Now check if it works. But remember: you can only turn on the microwave if there is a moisture-containing product inside - you cannot turn on an empty one. For example, place water in a heat-resistant glass.

How can I replace burnt mica in the microwave?

To understand what can be used instead of mica, you need to know its main qualities:

High resistance to thermal influences.
Ability to transmit radio waves.
Safety for cooking food.

Food grade plastic

Food-grade plastic, resistant to high temperatures, can serve as a substitute for mica based on these indicators. A part made from it will cope with the task perfectly because it has high strength and durability. True, this analogue is more expensive than standard protection.

Mica plate repair

The easiest way is to repair a burnt part and you can do it yourself without much hassle. The advantage of such a repair:

It will take 10 minutes.
No material costs are required.
There is no need to look for an analogue of mica.

If a mica plate burns in the microwave, do the following:

Carefully remove the part and clean the burnt area.
Turn it over so that the damage occurs on the wall of the frying chamber.
Don't forget to make a new hole to attach the board so that the latch holds it securely. That's it - you can use the microwave without fear for your health.

Is it possible to heat food without a screen?

Owners of microwave ovens often wonder: is it possible to turn them on without a gasket or do they need replacement? The screen is a prerequisite for the operation of the device. If it fails, the stove must not be turned on!

If you want to take a risk, the oven is fully operational without a screen. If you are careful and cover your food with a lid, you won't be able to use the stove for long until you buy a new plate. The main thing is not to delay the repair so that more expensive parts are not damaged: the cap and the magnetron antenna.

How can I replace a mica plate in a microwave if it is burnt?

Mica as a material has undoubted advantages:

resistance to elevated temperatures;
safety for cooking;
uniform distribution of microwaves in the microwave oven;
ability to pass steam through pores.

Therefore, when choosing a replacement element, it is necessary to take into account all these signs. If you do not follow this rule, there is a risk of poisoning with harmful substances that are very dangerous to health. Moreover, if low-quality materials are used in the microwave oven, there is a possibility of a short circuit. And it threatens that your kitchen appliance will completely fail, burn out and you will have to purchase a new unit. To prevent this, you need to carefully select the material from which the part will be made.

Most often, mica is replaced with food-grade plastic, because their main characteristics are largely similar. Plastic is also heat resistant, strong and durable. Only this material has one drawback - high cost. Moreover, it is not so easy to get.

Therefore, it is more practical to simply repair the failed part. The main feature of mica elements is the possibility of its reuse. You just need to properly care for this part of the microwave oven.

Procedure for burning a mica plate in a microwave oven:

Carefully remove the old part and scrape off the burnt part, clean it from dirt.
Turn the damaged part towards the wall of the microwave.
Make additional holes to securely fix the board.
Pin the element.

Useful tips

When removing the magnetron, follow the safety instructions: disconnect the device from the power supply, short-circuit it and the capacitor for a while.
Mica is fragile, so you need to cut it with a very sharp knife - a shoemaker's, wallpaper, stationery knife.
To prevent the accumulation of fat on the walls of the chamber, do not be lazy to clean it by preheating it for 10-15 minutes at low power. Then wipe the inside walls with a sponge and a detergent that breaks down grease.
When heating food, try not to use too large a container. Let’s say that a large plate does not touch the walls of the chamber, but when the tray moves, it can move. As a result, touching the walls, the dishes will thin and damage the enamel.

There are often articles online that recommend simply turning over the mica sheet. But with this solution, the problem will soon return with additional consequences: the cap and magnetron antenna will burn out. Then depressurization may occur - the stove will simply stop heating food, and repairs will cost many times more.

Why does the manufacturer use mica, what can replace it?

The material must have the following properties:

do not accumulate electricity;
be non-toxic;
do not melt at high temperatures;
It's good to let steam through.

If you use a material that does not meet the above requirements, you may be poisoned by harmful substances or suffer a short circuit. Mica is used mainly because it is cheap.

You can replace it with another material. Instead, you can use a heat-resistant dielectric - fluoroplastic. It is completely smooth and does not absorb fat or moisture. Food grade plastic is an excellent alternative to mica plates. It is much more reliable and durable, but also more expensive.

Replacing a mica screen is a simple process that you can do yourself. The main thing is not to ignore the breakdown and replace the plate in time. You can see the details in the video:

Features of material selection

If you know for sure that the mica plate burned out in the microwave oven, then the question arises of how and what to replace it with. It is important to understand that the selected material must meet the following characteristics:

It should not store electricity.
When exposed to high temperatures, the material should not melt or release harmful substances.
Have good steam capacity.

If you do not follow these rules, then you risk not only being poisoned by harmful substances, but also causing a short circuit. As a result, you will have to carry out not just preventive repairs, but replace expensive parts or buy a new device.