# Forum Home Renovation Plastering  Cutting cornice with a drop saw?

## Groggy

I have to cut some plaster cove cornice, two 22.5 deg internal and two 67.5 deg external. 
This would be quite easy on the SCMS but I am not sure what it would do to the blade - anyone?

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## journeyman Mick

I'd be more concerned about the large amounts of really fine dust the motor would ingest. I've seen an idiot do it, because he couldn't do it by hand and it caused a huge cloud of dust. 
Mick

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## Groggy

Didn't realise only idiots did that. I'll sharpen up an old butter knife then and build a specialised mitre box. 
thanks.

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## Rossluck

> I have to cut some plaster cove cornice, two 22.5 deg internal and two 67.5 deg external. 
> This would be quite easy on the SCMS but I am not sure what it would do to the blade - anyone?

  
I'm not a plasterer, Groggy, but I've done quite a few cornices and they're a cow of a thing. The best thing is the little mitre boxes they sell the plasterers and  cheap hand saw.  
Even then you have to study the damn things to get them right. I've had some moments with cornices.  :Confused:

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## Groggy

> I'm not a plasterer, Groggy, but I've done quite a few cornices and they're a cow of a thing. The best thing is the little mitre boxes they sell the plasterers and  cheap hand saw.  
> Even then you have to study the damn things to get them right. I've had some moments with cornices.

  Thanks for that, I've just made a 22.5 mitre box and will give it a go.  
As for the moments with cornice, I hear ya, man I hear ya!

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## journeyman Mick

I've found it helps to have a cornice offcut in my hand and hold it up in front of me as I look at where it will go, then roughly pencil mark which way it will be cut. For every join there's four different ways to cut the piece of cornice, but only one is right. 
Mick (who's never, ever cut one wrong...hey! did my nose just grow? :Shock:  )

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## ozwinner

Greg Bunnies sell a plastic making tool just for cornice, its a doddle to use, hey if I can use it anyone can.. 
Costs a cupla bucks.. 
Al  :Redface:

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## scooter

I agree with Mick, hold an offcut up & mark which is the "long" point & which is the "short" point. Ie. with an internal cut, the long points meet on the walls & the short points meet on the ceiling. Reverse for an external cut. 
Further to this, I reckon mark on the bottom (flat) edge which way the mitre is cut. Bit hard to explain this, will try & sketchup it.

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## Groggy

Thanks for the help guys, I've finished it now. The plastic tool I found useless because it flexed and moved whilst I cut. It also was only any good for 45deg, so I made a simple mitre box and cut the angles with the SCMS. Its not perfect but after a bit more tidying up I think it will be fine. Angles needed were 22.5 and 67.5

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## Skew ChiDAMN!!

:Thumb Yello:  
BTW, it's nice to see I'm not the only one who has to cope with the $%^&*!! man-hole being inside the cornice line.  :Doh:

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## Groggy

> BTW, it's nice to see I'm not the only one who has to cope with the $&#37;^&*!! man-hole being inside the cornice line.

   It happens to be where the old skylight was. Since the roof is full of aircon ducts, and the hole is conveniently on the other side of the ducts to #1 manhole, I decided to leave it there. Much easier to get up and around now, my poor son doesn't have to clamber over the dusty ducts  :Biggrin: .

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## scooter

Looks like it came together OK, Greg  :2thumbsup:  
Finished this earlier but forgot to post, might help someone.

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## Groggy

Thanks for going to that effort Sean  :2thumbsup:

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## Skew ChiDAMN!!

Have you worked out how you're going to cornice that section?  Sacrifice some access and pack the side out so you can run a clean cornice line?  Cut a rebate into the cornice?  (Can look good in some situations... but oh what a headache!) 
Or do you have something more devious in mind? 
Just asking 'cos it's the sort of thing I'm often asked to fix (you'd think the damned tradies'd know better!) and I'm always on the look-out for better ideas.   :Wink:

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## scooter

What about a return, like, ah, this.........ta daaaaaa  :Biggrin:

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## Groggy

I will be putting a frame around the manhole which will support the cover (white chipboard). The frame will be 70mm allowing a 20mm overhang inside the hole for the cover. The other 50mm will go to the cornice ends.

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## Groggy

> What about a return, like, ah, this.........ta daaaaaa

  very tricky Sean, I must admit that I saw that and like it, you've got me thinking...hmmm

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## Rod Dyson

Cutting cornice is very very easy if you follow a few principls. 
Vist my cornice cutting tips on my web site. 
Cheers.

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## Groggy

I did visit your site, thanks Rod, a handy resource.

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