Replacing microwave cardboard shield

Inside my microwave is a small 3x5" opening which is covered by a 3 x 5" piece of thin shinny cardboard. At one time, the four corners of the cardboard fit snugly into four small slots, so that it barely covered the full opening. Now those four corners have become broken and worn, allowing the cardboard to slip 1/4" below the top opening. Will this affect the performance or safety of the microwave? If so, can I replace the cardboard with a piece of non-shinny cardboard?

Thanks. digger

Reply to
diggerodell
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Is the shiny side around the light bulb that illuminates the interior of the oven? If so, replacing it with plain cardboard will be ok, but the light level will be much less. If it is anywhere else, the shiny side may be electrically conductive and part of the microwave system and should not be replaced with plain cardboard. Why not use duct tape to hold the original in place?

Reply to
hrhofmann

Both sides are shiny. I hesitated to use duct tape because of the possibility of fumes when the tape heated up but I'll give it a shot and only use 4 very small pieces in the 4 corners. Thanx.

Is the shiny side around the light bulb that illuminates the interior of the oven? If so, replacing it with plain cardboard will be ok, but the light level will be much less. If it is anywhere else, the shiny side may be electrically conductive and part of the microwave system and should not be replaced with plain cardboard. Why not use duct tape to hold the original in place?

Reply to
diggerodell

Use the metalic aluminum duct tape stuck to cardboard. OR order take out dinner from a restaurant that uses aluminum containers covered by a lid made from aluminum foil covered cardboard, clean the cardboard lid and trim to fit the space as needed.

Reply to
EXT

Uh, don't use the fabric stuff. Go get a roll of real duct tape, the sticky aluminum kind. It is actually rated for temps as high as the microwave box will actually get.

-- aem sends...

Reply to
aemeijers

Hmmm, How about holding cardboard with a drop of epoxy?

Reply to
Tony Hwang

I strongly suggest you post a photo because there are several openings in a microwave cavity:

  1. door

  1. steam/fumes vent

  2. magnatron duct: A metal duct running from the microwave-generating magnatron to the interior of the oven. This is covered by a piece of mica to keep the duct clean of food deposits. However the mica is transparent to microwaves. The mica resembles cardboard and is silvery-white when new but discolors from food as the oven is used. Don't run the oven without this cover in place, and don't substitute anything for mica.

  1. interior lightbulb window: Usually a series of small holes (1/8" to 1/4" diameter) to block microwaves, and there may be a metallic reflector behind the bulb. If you replace the reflector with anything but the original part, be sure it can withstand the heat (bulb can get very hot) and will not short against the lightbulb metal bottom or the wiring. Aluminum foil tape may be suitable here, but, contrary to another post, it is not necessarily made to withstand high heat since its adhesive may be rated for just 160 Fahrenheit. Some aluminum foil tape has adhesive rated for about 250-300F. If aluminum foil tape comes undone, it could slip and short.

Reply to
do_not_spam_me

Aluminum foil tape withstands attic heat better than ordinary cloth- plastic duct tape does, but alumium foil tape is not guaranteed for high temperatures since its adhesive is often rated for only 160 Fahrenheit, sometimes for 250-300.

Reply to
do_not_spam_me

Not disputing your statements, but aside from what you mentioned around the light bulb, how hot does your microwave get inside? I've had several over the years, and none of them got too hot to touch inside.

Never seen a consumer microwave with a visible mica window over a waveguide outlet. All the ones I have ever field-stripped had a plastic top to the cooking compartment, with a spinner above. But in re-reading OP's post, I wonder if you may be right, and they have some older pre-spinner model. In which case I recommend they just live with it while they save up for a replacement. New microwaves are getting absurdly cheap compared to what they were in the old days.

-- aem sends...

Reply to
aemeijers

Reply to
Oren

By process of elimination, the opening I've described is clearly #3 in Oren's list of 4 possibilities. Rather than replace it, I may try to use a very small piece of aluminized duct tape to reinforce the two corner points so that the mica cover would fit snugly in the two bottom grooves and cover the entire opening.

THANKS! digger

Reply to
diggerodell

re: "Never seen a consumer microwave with a visible mica window over a waveguide outlet."

My Sharp Carousel has one.

I've replaced it numerous times over the years, originally by spending too much on a original replacement part, more recently by buying a sheet of mica material from a local appliance repair shop. Now I cut my own.

They get food splattered on them, which burns a hole in them and then the spraks start flying.

Reply to
DerbyDad03

.

Normally I would agree that aluminum duct tape kicks fabric duct tape's a$$, but wouldn't aluminum in a microwave be a Bad Idea?

nate

Reply to
N8N

...

re: "wouldn't aluminum in a microwave be a Bad Idea"

Interesting tidbit about my old Sharp Carousel unit...

The manual says I can thaw frozen juice by putting the cardboard container - with the metal ring on the bottom - in the microwave after removing the top. I've done it hundreds of times over the years with no ill effects.

However, if I try to soften peanut butter and there is the smallest trace of the sealing foil stuck to the rim, the sparks start flying.

Reply to
DerbyDad03

Don't use aluminized duct tape or aluminum foil duct tape (they're different -- the foil tape is pure aluminum + adhesive, aluminized duct tape is aluminum over paper + adhesive). Use ordinary plastic tape until you get a new mica wave guide cover.

Reply to
do_not_spam_me

Do you mean inside the cavity where you place the food to be cooked, or just inside the overall cabinet with all the wires and components for the control of the oven?????

Reply to
hrhofmann

Hmm. Learn something every day on this here interweb thing. Guess my sample size of a couple dozen personal, relatives, and resurrected dumpster microwaves was too small.

-- aem sends...

Reply to
aemeijers

Wot can of tape can i use

Reply to
alwynarodriques135

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