On 4 Jul, 22:52, default wrote:
On Wed, 04 Jul 2007 20:37:48 +0100, "Ron(UK)"
wrote:
default wrote:

Has anyone ever replaced a window? Mine doesn't look like mica but
does look like some sort of hard mineral. It is only fastened over
the opening with a couple of push in plastic pins and looks like it is
intended to be easily replaced from the oven chamber without taking
the whole thing apart.

The window - or waveguide cover as it`s called - is available by the
sheet. It`s either laminated mica or fibreglass[1]. You simply cut it to
shape using the old one as a template. pierce the holes and replace the
plastic rivets. Clean any grease and carbonised crap out of the
waveguide while you're in there.

[1] Some ovens have a purpose made moulded plastic cover which may or
may not be available.

Ron(UK)

Thanks for that. It makes a lot more sense than either discarding the
whole oven or using it without any window (no window could become a
fire hazard and really screw up the oven).

The stuff I have doesn't look/feel like mica or fiberglass. The
previously burned parts (since "cleaned") appear somewhat translucent
but don't heat in use.

Sorta like mica - but without the crystal structure.

Amateur radio enthusiasts have been putting plastics (dielectrics)
into microwave ovens for years to see if they absorb microwave energy
- a window cover can't be that big a deal - just my trailer trash
understanding of the universe.

Ron(UK) gave the right answer. One extra point though, with the
waveguide cover off, clean out all traces of carbonised crp, or the
same problem will occur again after a while.

While you could use any non-rf-absorbent plastic outta the bin, many
give off toxic fumes when they burn, and many will catch fire in
style, so you should use the right type of material for your own
safety.

When heating tiny amounts of stuff, which dont absorb rf well, put a
cup of water in there with it. Avoids arcing occurring, and arcing
turns things to carbon, which you dont want in a nuke.


NT