# Forum Home Renovation Plastering  Cutting cornice with Mitre Saw

## patty

Help can anyone tell me what the angles are to be set on a drop mitre saw for cutting 90x 90 cove cornice?? 
Thanks
Patty

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## wheelinround

depends on mitre to be cut if its and inny or an outy

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## patty

Cheers Wheelinround I forgot to add that to the thread I need Both internal and external left and rights

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## Rod Dyson

You need to set the saw at 45 deg for both internal and external. 
The cornice has to sitting as it would in place.  The bed of the saw will be the ceiling, in other words the cornice is held upside down. 
When you mark the cornice the side that retains the line will be the external mitre and the side without will be the internal.  The edge that you mark the length will be on top and will be the edge that goes against the wall. 
Hope you can follow that. 
Cheers Rod

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## namtrak

Drop mitre saw? 
Rod may have more of an idea, but I would have thought a plasterers mitre box and hand saw would have been more practical and you wouldn't have the possibility of plaster dust seizing up your saw motor. 
That's all I have ever used. 
Cheers

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## montiee

I've done this job using a handsaw and I can honestly say that I believe if you approach this with an electric drop saw you will rip the plaster to pieces and cause a huge mess. I guess it depends upon the cornices and how thick they are but when I was doing it it was gently gently with the handsaw.

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## patty

Thanks Rod I bought a 3 mtr piece from Bunnies yesterday and made an absolute abortion of the angles I even bought the gyprock mitremasta plastic template guide with no luck!!  
This is just standard every day 90x90 cove cornice the drop saw cuts it very neatly yes it creates a bit of dust but the cut is spot on... 
Ill give it a go and see if I can waste another piece of Cornice....

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## Rod Dyson

Have to agree I would not use a drop saw to cut cornice. A mitre box is better because it hold the cornice in position while you are cutting. 
The biggest mistake made by the DIY when trying to cut cornice is that they just lay it on its back and try to cut at 45deg. Both edges will match but you will have a giant hollowed out center.  The cornice must be turned up as it would sit in place with the wall member facing up.  All measurement need to be made on the wall member only.  
Cheers Rod

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## patty

The bed of the saw will be the ceiling, in other words the cornice is held upside down. 
Hi Rod now I'm not trying to be a smart ???? here and I hope this isn't a stupid question but is there a top and bottom to cornice is there.. or are you just using the above as a figure of speech.......... geezus I think Im going blonde!!

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## Rod Dyson

Figure of speech when it comes to 90mm cove as it is the same either way. 
What is important is to know that you are always marking the wall member and commence the cut from the wall member. 
This will also help you work out which direction to cut the mitre etc.   
It is of course more true when cutting decorative cornice that has a different profile on the wall and ceiling. 
Hope this clears this up. 
See this web page it might help. http://www.how2plaster.com/mim.html 
or http://www.how2plaster.com/bcc.html

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## Dean

Been there done that with a powered mitre saw... It was an old one and to be honest, it was a bit of a brain strain and dust everywhere!  
Ended up getting one of those Mitremasta things you said you purchased. These are simple to use, once you figure out how to use them. Took me a while to figure it out actually. There was a guide on their site but seems to have gone now. But basically the cornice gets referenced starting at the outer ends of each leg of the plastic tool, not at the apex, and the inside cove shape of the cornice (the side you actually see when its on the wall) is the side you reference the mitremasta against. 
Hope that is of some help.

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