Cracked microwave = fried gonads and melty brains!

December 28, 2010 1:44 PM

My microwave has a hairline crack inside. Gonads will fry and brain will melt: [Y/N]?

I had gotten a used microwave a month ago or so and just now noticed a hairline crack inside, across the bottom edge of the back wall, hidden from view by the turntable. Will there be a problem with shielding? If so, is this fixable? I'd rather not give up the microwave because it's a rare, peculiar, vintage (if '90s is vintage now) model...

posted by Ky to Technology (11 answers total)

Best answer: You're safe. You may have noticed that the front of your microwave has a glass or plastic window with a mesh grill in it. That mesh stops microwaves, not the window. The holes are smaller than the wavelength of a microwave, so unless the hairline crack is thicker than one of those holes, you should be okay.
posted by justkevin at 2:19 PM on December 28, 2010 [2 favorites]

Best answer: Home microwaves usually have a wavelength of about 4 inches, so leakage through a hairline crack should be negligible. (It's how they can build a window so you can watch your food overcook.) I'd be more worried about potential arcing from the sharp edges of the crack than leakage.
posted by KirkJobSluder at 2:53 PM on December 28, 2010

Best answer: You can test if it's leaking by taping a chocolate bar on the outside of it and letting it run. If the bar melts, you're brain probably is frying too.
posted by about_time at 4:07 PM on December 28, 2010 [2 favorites]

Best answer: The holes are smaller than the wavelength of a microwave, so unless the hairline crack is thicker than one of those holes, you should be okay.

This is not exactly correct. Microwaves are transverse waves that oscillate in planes. Electromagnetic waves can propagate through a slot or crack much more easily than through a circular hole. This is why electronic equipment usually has ventilation holes, not ventilation slots. High end PC enclosures will have a metal braid gasket at joints to prevent leakage through the slots.

However, the crack in your microwave probably doesn't won't leak anymore than the crack around the door so it shouldn't be a problem.
posted by JackFlash at 4:23 PM on December 28, 2010

The crack will harbor some bacteria, so clean it carefully.
posted by Mom at 4:25 PM on December 28, 2010 [2 favorites]

Best answer: The worst you will have to worry about is bad cordless phone and WiFi reception. Microwaves are non-ionizing radiation which means they can't cause cell/DNA damage, they can only heat things. Even if the crack was significant, being on the back side makes it very likely that it would even be able to reach you, because you're talking about some kind of magic bullet scenario now where it reflects off multiple walls in just the right angles to hit you without also dissipating (at a rate of 1/r^2) to the point where it's negligible.
posted by Rhomboid at 4:29 PM on December 28, 2010

very unlikely
posted by Rhomboid at 4:29 PM on December 28, 2010

I think I must be going crazy, because I find myself wanting to see this peculiar, vintage microwave, especially since a previous question you asked also has to do with your unique microwave. It's like with pets - show us a picture! Then we might be able to better help you.
posted by analog at 7:05 PM on December 28, 2010

Someone can correct me if I'm wrong but I believe some of the really vintage microwaves didn't even HAVE glass, just a screen like in a window. So I'm thinking you're OK!
posted by ista at 7:57 PM on December 28, 2010

Response by poster: True, ista, it's not *that* vintage, but I feel anything before 2000 is pretty vintage for certain electronic devices.

analog: Ha! My previous nuker question was about a gift I had gotten for a friend, but this one is a 1995 Sharp Half-Pint (fuzzy pic of same model). It's very small and weighs a crapton.

Thanks all, for the tech details!
posted by Ky at 8:42 PM on December 28, 2010

Yay, I'm glad I asked, it's so square and little and cute! Good luck with it.
posted by analog at 3:39 PM on December 29, 2010