Paint inside microwave is chipped and blistered. How do you fix it?

see the troubleshooting section and follow the steps and fix it.
God bless you

Waveguide Cover

If the microwave is sparking or arcing the waveguide cover might be damaged and shorting out. Try removing the waveguide cover and see if the problem goes away. If there are any damaged spots in the microwave ceiling or sidewalls, repair them and paint them with microwave oven paint. Replace the waveguide cover if it is burnt or if it will not stay in place.

Microwave Oven Paint

If the microwave is sparking or arcing on the side walls the paint might have chipped causing pitting in the metal oven wall. Use microwave safe paint to touch up any bare metal spots.

Rack Support

If the microwave is sparking or arcing near one of the rack supports, remove the support, repaint any bare metal, install a new support.

follow this steps and fix it. God bless you

Waveguide Cover

If the microwave is sparking or arcing the waveguide cover might be damaged and shorting out. Try removing the waveguide cover and see if the problem goes away. If there are any damaged spots in the microwave ceiling or sidewalls, repair them and paint them with microwave oven paint. Replace the waveguide cover if it is burnt or if it will not stay in place.

Microwave Oven Paint

If the microwave is sparking or arcing on the side walls the paint might have chipped causing pitting in the metal oven wall. Use microwave safe paint to touch up any bare metal spots.

Rack Support

If the microwave is sparking or arcing near one of the rack supports, remove the support, repaint any bare metal, install a new support.

Rust can form from the steam and condensation as you say, and it's a good idea to always cover food and wipe the oven out after using it. You can sand off the bad paint and rust the same way you can on a car, and then touch up the paint if it's a minor amount. Spray paint specifically made for microwave cooking cavities is available. (You don't want to use paint that may have metallic components.) It may be available locally if you have appliance parts stores in your area, and you can find the paint online as well. There's no need to replace the oven just yet, unless you find a good deal on a new one and you're looking for an excuse.

I have painted many Microwave oven cavities. You have to sand down the pealed off rusted areas and completely clean and degrease. Before painting, I use laquer thinner as a cleaner degreaser. Fumes can be a bit strong but it has worked well of me. I normally buy an automotive spray paint. They have a lot of different colors and a lot of the import colors can really come close to the color inside the microwave. Spray on thin layers till you get good coverage and make sure you let it dry thoroughly before trying to use. The paint in a Microwave isi not a special microwave energy protective paint. it is only there to make it look pretty and protect the metal. So a good automotive paint normally works fine.

Since the cavity metal of the oven is chipped or charred, it will have to be sanded smooth and clean.

Then you can apply some high-temperature appliance paint, available from places like Wal-Mart or Lowe's.

If it is not repaired, the rust will worsen until the cavity is damaged beyond repair.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

This is often caused by spills and condensation.

The metal will have to be sanded smooth and clean.

You can use a wire brush and naval jelly to get rid of the rust.

If any rust remains, you can use Rust Reformer paint to stop the rust process, then sand it smooth when it's dry.

Then you can apply some high-temperature appliance paint, available from places like Wal-Mart or Lowe's.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

Hi,

As long as the oven's metal bottom is sound underneath the rust, there isn't a problem. The cooking chamber walls are so thick and highly conducting that they reflect the microwaves extremely well even when they have a little rust on them. However, if the metal is so rusted that it loses most of its conductivity in the rust sites, you'll get local heating across the rusty patches and eventually leakage of microwaves. If you're really concerned that there may be trouble, run the microwave oven empty for about 20 seconds and then (carefully!) touch the rusty spots. If they aren't hot, then the metal underneath is doing its job just fine.

Thanks.

1) How is the cavity damaged? Is it just peeling paint, or is it rust? If it's rust then the microwave could be dangerous.

2) The antenna cap usually has a small hole in the centre, but if there are any other holes in it the magnetron itself could be damaged, and holes caused by the magnetrin arcing.

Moisture accumulation can sometimes be caused if the cooling fan is not running properly or if the vents in the back are blocked or there is not enough free space around the sides and back of the microwave.

One thing that helps is to keep the door open a few minutes after using it and to wipe down the inside after use.

If the cavity metal of the oven is chipped or charred, it will have to be sanded smooth and clean and dried thoroughly.

Then you can apply some high-temperature appliance paint, available from places like Wal-Mart, Lowe's or Builder's Square.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

THERE IS SPECIAL MWAVE CAVITY SPRAY .MAKE SURE YOU SANDPAPER IT THEN USE NORMAL PRIMA ALLOW TO DRY USE FINE SANDPAPER JUST TO MAKE SURFACE RIGID THE SPRAY