# Forum Home Renovation Plastering  Cornice angles......

## shrek4

Hello all, I'm pulling my hair out on this one. Was putting up cornice today and couldn't for the life of me work out how to do the cornice on the bulkhead where the angle is not the standard 'internal' or 'external'  :Mad:   :Doh:  .  
In the pic you can see what I'm talking about, its on section above the cupboard on the right of the picture.  
Help would really be appreciated  :2thumbsup:  .

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## Rod Dyson

> Hello all, I'm pulling my hair out on this one. Was putting up cornice today and couldn't for the life of me work out how to do the cornice on the bulkhead where the angle is not the standard 'internal' or 'external'   .  
> In the pic you can see what I'm talking about, its on section above the cupboard on the right of the picture.  
> Help would really be appreciated  .

  It would be very close to a 45 deg angle which would mean you would cut the mitre in say 90mm cove at 45mm. 
Although on all obtuse angles like this I measure the mitre by holding an off cut in place and rule a line top and bottom. Do this on both sides and you will get the intersecting point on the ceiling.  Now on a piece of cornice hold it up and mark the bottom and the intersecting point at the top. Square a line across the cornice from the bottom mark to the top and measure the distance from the top mark to the bottom mark (now marked at the top).    This will give you the exact measurement to cut the mitre. 
I usually hold it in the mitre box so it is sitting at the right angle, but where I want to cut hangs out past the end.  Then line you saw up to both marks keeping the saw dead straight cut from mark to mark and you will get a perfect fit. 
Cheers Rod

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## shrek4

Thanks Rod, I've tried all my might to understand. I must be thick. I'll read it again on the weekend, hopefully I can get it right then. 
Thanks for trying.

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## gpkennedy

Shrek, I assume that you are talking about the cut off corner just above the jugs in the top right corner of the pic where the bulkhead touches the ceiling.
Let's start with the easy ones first.  All the other corner angles are 90degrees so we cut them at half that ie 45degrees.
The cut off corner has angles at about 230 deg guessing from the pic.  You need to calculate this.  With a ruler and pencil draw a line on the ceiling which extends the flat side of the bulkhead.  This gives us 180 deg. Now with a protractor you want to measure the angle smaller angle, I'm  guessing 50deg.
Add 180 to our calculation.  180+50=230
Divide 230 by 2= 115
So this determines your cut, it is obviously going to be greater than 90deg.
Hope this helps.
I would do all the 45 deg cornice cuts first to get the hang of cutting cornice.
Hope that this helps.

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## SMITHTOWN

Are the joys of doing Cornice . Easy it's all upside down and back to front ( if that makes any sense ) not meant to be easy pay a plasterer should'nt cost more $200 save the head f##ks trust me being there done that. Or do an apprenticeship pays @@@@ and only takes 4 years . Good luck.

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## shrek4

Thanks guys, I've put up cornice in the rest of the room, this wasn't too much of a headache, just have the last bit (above the jugs) to go. Will have another go at it on the weekend.

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## Rod Dyson

> Thanks guys, I've put up cornice in the rest of the room, this wasn't too much of a headache, just have the last bit (above the jugs) to go. Will have another go at it on the weekend.

  Basically it is cutting the mitre half way. instead of a 55mm measurement it will be 27.5mm.   
But if the angles are not exact then you can get it exact by marking the intersecting points on the ceiling by holding an off cut in place.  Then hold the cornice up and mark the bottom and the top where the intersecting mark is and that is what you cut it at.

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## bpj1968

Hopefully this explains what Rod was talking about..  Imagine as if you are looking up at it.

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## shrek4

Thanks again everyone, Brian esp, your pics have helped me 'picture' it. I'll let you all know how I go.

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## Tarasa

Grab some cornice offcuts and practice on a couple. Only need to be a few inches long to lay them in place and check your cut angles are right. Then....cut the real thing.

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## shrek4

Well, reading the posts again and following the tips from Rod and Brian I've given it a go and after a few (several) test runs I've finally got it right. It really wasn't difficult, was one of those spacial awareness things that you have to get your head around.  
Thanks again guys.

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## Rod Dyson

well done

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