What a pane.

Multimaster.

You know you want the real thing.....

New glass cuts easier than old glass.

You're approaching this from the wrong end.

If the fan casing is plastic it is probablly easier to thin it down than change the glass.

If it all falls to pieces it can probably be stuck together once in place with silicone.

In the last resort conceal a small MP3 player with a recording of a fan whirring within the casing.

Owain

Who's a silly handyman then ;-) better to have the hole slightly oversize rather than undersize,were glass is concerned anyway.

You measured the hole too small and then fitted the pane before trying the fan in.

You've been watching me DIY haven't you!

You could try this....

Two pieces of thin plywood with the correct size hole cut out on both,position the two pieces on either side of the glass hole and clamp them slightly tight so as not to crack the glass. Then use your dremel grinding tool to grind off the excess glass around the hole level with the the plywood cutout hole.?

Dave,

I won't state the obvious. ;-) but with care, and using a Dremel type of tool with the correct stone, it is possible to grind the edge of the glass to the diameter required - but the odds are that you will break the stuff.

Try cutting a slightly larger diameter hole in a piece of 3/4" ply wood than required by the fan, put that into a warm room and lay the glass flat on top of it so that it is well supported (and the hole is over the hole in the ply) and then carefully 'attack' the edge of the hole in the glass with the abrasive stone - (damn, this reads just like and American workshop car manual that I am having a look at).

There is no real secret to the job - other than confidence, having the glass at a warm room temperature, well supported and taking your time. Oh, and an extra pair of hands would be useful to stop the glass slipping about when you are working on it.

All the best with this job.

Tanner-'op

Cheat. Use a bit of plywood and make do until Monday (or next opportunity for doing it). Or if you have some suitable plastic sheet material...

Do you have a tile cutting machine? The sort with a powered water lubricated diamond wheel.

I you only need the hole to be bigger in a few places this will be the easiest way. I have used one of these for this purpose but not to enlarge a hole.

mainly on the circumference, I think, Ed

Dave didn't say how much "slightly" is - a mm ?

Shaving it off the fan housing (assuming it's plastic) I'm sure would be the path of least resistance

It may sound daft but I have enlarged a hole like that with a diamond nail file from my wifes handbag.

(She never noticed)

Oh thanks for that George. I did ask the bloke for a 6" hole...

Indeed, the circumferance.

About 2mm on the diameter, so 1mm on the radius.

Alas not much of it to shave off.

fwiw I spent a whole afternoon grinding glazed tiles with a stone in a die grinder and nothing broke, so i'd be fairly tempted to try that

NT

================================== Tile file used gently along the edge of the glass - not across:

Cic.

...

What were you doing in your wife's handbag?

I mean, would you like it if she went through your pockets?

Mary

So all thats needed now is for you to send your wife round to meet the OP and it's sorted...

But if you interfere with it and the glass breaks, no come-back. Alternatively, be patient, take the glass back on Monday with a 6" ruler and wave both under the bloke's nose.

MM

Wave the fan under his nose, which is what I would have done in the first place

treat, in under half an hour I had milled off enough to get the fan to slide in.

It was only then that I realised the PCD for the fixings screws is larger than 6"!

Finally - I read the instructions - it needs a 7" hole!

sound of beer can opening