Microwave Oven Universal Mica Wave Guide Cover Sheet measurement
150mm x 120mm, Cut To Size
Size correct to approx 1mm Variance

Microwave Mica Wave guide Cover

Where is it? Inside the oven cavity, normally on the right hand side or in the upper ceiling you will usually see a small cover that looks like it is made of shiny cardboard. It is often secured by one or more screws.

What is it? It is called the wave guide cover. It is usually made of a material called Mica.

What does it do? Its purpose is to cover the aperture through which the microwaves enter into the oven cavity from where they are produced by the Magnetron which is hidden behind the control panel. It stops moisture and food particles getting into the delicate electrical parts of the microwave.

What do I need to know? If your microwave is working ok and behaving itself then there is nothing to worry about, but there may be one of three possible problems that may affect the correct workings of the oven.

1. The wave guide has fallen off.
2. It has one or more holes in it.
3. It is arcing or sparking during use (often you will hear a crackle of noise during operation.

In any eventuality the wave guide should be replaced. If it has fallen off or got a hole in it then there is the risk of food or moisture getting into the waveguide which will reduce the efficiency of the oven. If it is arcing or sparking then continued use could damage other components in the microwave including the oven cavity which could be costly to rectify.

What should I do?
If there are any issues with your waveguide cover it should be replaced. When new the mica sheet is rigid and firm. Over a period of time it absorbs moisture and gets food splattered onto it. It then becomes soft and weak. The cover can be replaced either with a suitable replacement made by the manufacturer of the microwave or if the old cover is in good enough shape to be used as a template, blank sheets of mica can be purchased and cut to fit.

A single Sheet of replacement wave guide cover material for all types of microwave ovens. This mica sheet is usually found inside the cavity on the right wall or upper wall of the Microwave oven cavity. It covers the entry point that the microwaves enter the oven cavity.

Fat and food splashes that gather on the cover over time cause the cover to overheat, burn and become soft. This can lead to sparking around the wave guide cover during the microwave cooking cycle. If this is not dealt with it can lead to the cavity being burnt as well. It is important to regularly inspect your wave guide cover for burn marks and replace as necessary.

The sheet supplied should be big enough for most domestic ovens. The idea is that you cut and trim this sheet to the size of your original cover. The material is easy to cut with a sharp knife, Stanley blade or scissors. No special tools are required. If your old cover has a screw hole in it then a leather punch can be useful to make the hole. Otherwise the point of a screwdriver can be used to make the hole.

Purchasing a universal sheet like this is often the easiest option to obtaining an original cover as the originals can be expensive and in some cases difficult to source especially with all the strange brand names sold by supermarkets etc.

The specification of the sheet is as follows:

• Wave guide cover dimensions: Various
• Wave guide cover thickness: 0.4mm
• Wave guide material: Mica