Why can't you put metal in the microwave?

Answer 1

The best answer (with just a bit of technical stuff).

Ask around to find out if using metal in a microwave is okay, and the answer is often a no. A no is a safe answer, and that's for sure. There are instances where metal is absolutely to be avoided. Metal utensils are a no-no, and the use of plates with metal designs should be avoided. That said, there are times when a bit of foil greatly helps with things and can be used safely. But the situations will vary. With that in mind, let's look at, "Is it save to put metal in a microwave oven?"

It may be yes, or it may be no. Here's a suggestion. Let the manufacturer make the call on this one. Generally speaking, the magnetron (the component in the microwave that generates the microwave energy) won't be harmed by metal in the cavity (the cooking area). But any metal within the cavity might act like a microwave antenna, and this may create arcs, and even start a fire within the cooking area. This will melt and burn things within the cavity, and almost certainly damage the door, which will make the oven unsafe to use (if it doesn't actually disable the oven). But setting aside those issues, let's look more closely at the microwave and how it should be used.

No one on this board can tell for sure without the owners manual or the model number of the machine in question (so one could look at the owner's manual) whether metal can or cannot be used in a given machine. "No" is a safe answer, but it may not be correct. A microwave has some cooking capabilities that may not be obvious, and anyone who owns or uses one of these puppies should know whether or not something like foil can be used inside it. There are even some microwaveable "fast foods" that have a bit of foil in the microwaveable package. Additionally, some microwave ovens allow a bit of foil over a portion of a food item being cooked, like the ends of the drumsticks on a bird. If the manufacturer's manual is not handy, it may be possible to go to the manufacturer's web site and actually view it online. Certainly the pamphlet can be had by ordering it. Get the manual. Read it. There might be several things in there that weren't obvious. Like whether or not foil can be used in the oven. That's why the correct answer may be either yes, or no.

If you have any doubts or issues, or you are not familiar with the manufacturer's instructions for a given unit, the "no" is a safe default answer and should be applied. But further investigation and thinking is in order if a microwave user wants to get the maximum out of a unit and really develop insight into the truth in the answer.

Surf on over to the USDA page with microwave use and safety suggestions. Scroll down to the section on the use of foil and see what they have to say. That's a good place to start, and you're just a few keystrokes and mouse clicks away right now.

Answer 2

The micro wave makes heat from it's micro heat waves, not by fire or a very strong light. There is something about those heat waves that makes it burn metal and it hits the metal so intensely that it can set it on fire.

Answer 3

The heart of the microwave is the magnetron which is nothing more than just two magnets that radiate energy or electrons at very high frequencies which is then transmitted like an antenna through a waveguide who's job is to concentrate and direct the energy so it can bounce off the walls of the cooking cavity. This high frequency excites the water molecules in your food in the form of vibrations and heat is produced as a result to cook your food.

When the flow of energy in the cooking cavity or inside the oven is disturbed by a metallic object it can cause a spark. The spark is an arc of electricity between two irregular points of metal in close proximity or to the metal wall of ther cooking cavity. The build up of energy between the two points of the metal will overcome the insulation properties of air and start conducting or arcing. This will continue as long as the energy is constantly being provided by the magnetron. Also keep in mind the size of the cooking cavity is designed for the frequency and energy output of the magnetron, placing a metal object within the cavity can cause reflections back to the magnetron, damaging it.

There are some microwaves that allow metal to be used inside so you must follow the manufacturer's manual. If your microwave shows damage in the form of pit marks along the walls or the mesh screen in the viewing window, you might want to replace it, these are areas where the microwaves can escape through.

Answer 4

It gets induced with current, which may make it hot, or spark.

It depends on the length of conductor, whether it resonates.

Some metal objects, like wire stands, can be made to work inside a microwave.

Answer 5

The metal object would usually act as an antenna to the microwaves, meaning current would be induced in the object. The object will sometimes arc between adjacent metal points. But the induced current normally causes metal object to heat up very rapidly.

Answer 6

It doesn't. Watch the "Myth Busters" in season 1 and season 4 try and fail. All it does is heat up the metal. What metal can do to a microwave is the same thing that would happen eventually if you ran a microwave empty. The waves bounce back off the metal and chances are that eventually they'll hit the "magnetron" which is what creates the waves, resulting probably with the breaking of the microwave.

Answer 7

No, no matter what mode the microwave is in no metal should ever be used.