No, I don’t have any foil in it. But it sometimes zzzzzapppps and sparks, and I can’t figure out why.
Here’s what I’ve noticed:
Melting butter will make it zzzzzapppp every single time. Doesn’t matter what container I melt it in or where in the microwave I place it.
Warming caramel sauce (sugar, butter, cream) will make it zzzzzapppp about two thirds of the time. If I put a small cup of water in the microwave next to the caramel sauce, it seems to prevent it. (I’m not sure of that, because I’ve only warmed the sauce twice since I started putting the cup of water in there; hasn’t done it again, but it’s a very small sample size.)
Gravy - zzzzzapppp about half the time.
Soup, burritos, left overs, steaming veggies, etc. - rarely a zap.
My hypotheses at the moment have to do with volume and/or fat content. It seems that a small amount of a very high fat item triggers the zzzzzapppp. Is this even possible?
The microwave is made by GE and was bought at a scratch and dent sale several years ago, but has only been in use for a year. It’s had this problem for the whole time we’ve been using it.
The most common, easily fixable problem is due to dirt on the surfaces of the microwave interior. Especially dirt that has become carbonized. Clean thoroughly the interior of the microwave: top, bottom, sides, door. Use a slightly damp cloth. Don’t spray into the microwave with any cleaner. Spray onto the cloth and then rub. Finish with a low residue cleaner like a glass cleaner.
There are other causes, but fixing them is beyond the capability of a DIYer. In which case replacement is the best solution.
For a long lived and properly operating microwave, keep the interior clean. In particular, keep things covered when heating. The fumes and such can float up into the waveguide and reduce its power and lifespan.
That’s usually caused by arching. Not sure of the physics, but if you have any kind of metal that is separated by a gap, you’ll get that. I used to have a mug that had gold foil on the outside - It was the official seal of the LA county coroner (don’t ask) and every detail was highlighted in gold. It would occasionally pop when in the microwave. Actually, it was probably pretty consistent and just noticed only part of the time. And that was only a 600watt oven.
Since you’re not using any containers like that or any foil, I would check under the tray or carousel turntable and see if something metallic might have gotten down in there.
Other than that, I don’t know. But the fact that you can squelch it to some extent by putting a container of water in there might indicate a problem other than the magnetron. But that’s just a wild ass guess.
A lot of foods will arc in a microwave. Cut grapes are pretty reliable at it. Cut the grape until just a tiny bit if skin keeps the two halves joined together, and watch the sparks fly. Other veggies aren’t quite as reliable, but beans, carrots, and a lot of others will sometimes arc.
The mineral content of the soil that the veggies grew in, combined with the power of your particular microwave, will usually determine whether or not your veggies arc. Cut veggies with nice sharp corners and edges are also more likely to arc than non-cut veggies. If Trader Joe beans arc reliably, they must consistently have their beans grown in soil with a high mineral content.
Adding a cup of water reduces the arcing simply because there is more stuff in the microwave to absorb the radio waves. The magnetron only emits a certain amount of power. If some of it goes into the water, that means there’s less of it available to end up in the veggies.
As for the metal foil on your cup, sometimes things like that will arc and sometimes they won’t. The radio waves end up inducing eddy currents into the metal. If you’ve got a thick piece of metal then usually all that happens is that the metal gets hot, and if it’s thick enough it may be fairly slow to heat. If you’ve got a thin piece of metal with a sharp edge on it, sometimes you can get arcing since charge tends to build up along sharp edges. Irregular metals are more likely to arc for the same reason. Forks usually don’t arc because the tines are too far apart on your typical fork for an arc to form.
Thanks for the advice, though.