Microwave combi oven

[gordon stephenson]

I have wondered for a couple of years now, and finally remembered to ask the question of our clever forum members, Metal in microwaves was always a no no, but my combi oven has metal shelves and metal shelf runners HOW? is it OK now,

 

[Maker]

Metal is fine in the microwave, it's sharp edges you can't have. If you look closely the metal shelves will probably have quite carefully deburred and rounded edges. Microwaves have always been made of metal, why should having metal inside it be any different?

 

[mike os]

imodern combo ovens are ok just use the shelves supplied and read the instructions

Don’t use non microwave shelves

 

[bourbon]

Ok, so no sharp edges? How come the cup that I put in with a gold-coloured rim, sparked all over the place

 

[fractured]

Heated a carton of custard in the microwave. Never thought that it had a foil inner! Pressed go and walked away. A weird noise came from the microwave, I walked over to look and it was arking between the carton and the inner of the microwave. Feck - never seen it before and it was quite startling.

When I got the carton out some of it was burnt away and smoldering. I won't try that again!

I don't think this was a combi one, but not sure.

 

[Ruffian]

Put a light bulb in water and turn put it in the microwave.

Interesting to see it light up,

 

[Maker]

Ok, so no sharp edges? How come the cup that I put in with a gold-coloured rim, sparked all over the place

The gold rim is essentially a thin foil, maybe sharp edges was the wrong term, no thin sections. Foil will spark but a bit of ally plate won't.

It's nothing to do with earth paths, I leave spoons in the microwave all the time when I'm reheating things so I've got something to stir it with. It's in a plastic tuppaware, on a glass plate, there's no earth path and no spark either. I think mum's Siemens microwave actually tells you to leave a spoon in cups of liquid when you microwave them, not sure what it's supposed to do but there's no earth path though a porcelain mug and that doesn't spark.

 

[PhillipM]

I mean foil does have sharp edges, on account of being so thin. It's like having a sharp tip on a spark plug.

 

[Morrisman]

I have wondered for a couple of years now, and finally remembered to ask the question of our clever forum members, Metal in microwaves was always a no no, but my combi oven has metal shelves and metal shelf runners HOW? is it OK now,

I've used metal in microwaves for years. Not sure when it all changed but I know it was a big problem at some stage. I have metal trays to cook in/on that cause no problems.

 

[voipio]

Sharp edges are not the issue in microwave ovens. A straight piece of aluminium foil placed in a microwave oven won't cause issues, but fold it back on itself with a gap and, with particular lengths, related to the RF wavelength watch the sparks fly! The same with the cup having a gold rim. The microwaves RF power induces currents in the gold rim that can be quite large, causing it to behave like a fuse.

 

[prepman]

Sharp edges are not the issue in microwave ovens. A straight piece of aluminium foil placed in a microwave oven won't cause issues, but fold it back on itself with a gap and, with particular lengths, related to the RF wavelength watch the sparks fly! The same with the cup having a gold rim. The microwaves RF power induces currents in the gold rim that can be quite large, causing it to behave like a fuse.

Having had combination ovens for 20yrs or so. There is a tolerated order of metalwork combinations mentioned in the manual. Seems to all be down to their arrangment.

 

[AVI_8]

Ever seen a Van de Graaff generator?

Science teacher left me standing in a classroom holding one for an entire lesson for miss-behaving.
Cant imagine that happening nowadays.

 

[Burdekin]

I always take the metal shelf out when using the microwave only. Never knew you can leave it in.

 

[Morrisman]

I always take the metal shelf out when using the microwave only. Never knew you can leave it in.

Microwave furniture, for various types of gourmet cuisine.

 

[Guineafowl]

It’s to do with the shape of the metal. As you see below, it’s hard to predict what will arc and cause problems, so the easier rule is no metal at all:

 

[Maker]

Sticker on mum's microwave:


No idea why, or if she does it.

 

[optima21]

the spoon in the water is because you can superheat water in microwave and it doesn't boil, that is until you take it out and put something in it (like a spoon) and it will boil over

 

[Guineafowl]

^^ The spoon is to prevent superheated water.

If you put a spoon in a fizzy drink, notice how bubbles form all over it. This is because bubbles need a ‘nucleation point’, basically a point at which to start forming.

Heated water in a perfectly smooth mug might be above boiling point, but not boiling because there‘s nowhere for the bubbles to start.

If you then insert a spoon/nucleation point, the water can suddenly boil.

Edit: X-post with optima21

 

[James1979]

That’ll be why every offshore installation and murican owned facility I’ve been in has big signs saying not to boil water in them.

 

[bricol]

Science teacher left me standing in a classroom holding one for an entire lesson for miss-behaving.
Cant imagine that happening nowadays.

Yeah, you'd be allowed to carry on being an annoying little **** affecting everyone else's chance to learn something

No offence