How do i cut corner angles of ceiling cornices?

[Petervn]

I am trying to cut ceiling corniches to fit the corners but I can’t get the angles correct. I am using a mitre box and hand saw. Does anyone have any tips?

[JacobZ]

Hi @Petervn,

Thank you for your question and welcome to the Bunnings Workshop community, it is fantastic to have you join us.

Cutting cornice when the walls aren't exactly 90 degrees can be quite tricky due to the compound nature of the angle required to make the join meet up perfectly. 

The best suggestion I can offer, is to take some small offcuts and adjust your cuts slightly until you are happy with the join. Once happy, you can transfer the angle onto the final piece and then cut it to size and install.

Remember that once the cornice is installed, you will need to coat the corners with plaster anyway, so small gaps can be fixed. 

You might like to have a look at How to make cornice corner joints with a raked wall for some additional information.

Allow me to tag some of our helpful members to see if they have any advice, @Jewelleryrescue, @Dave-1, @Noyade.

Jacob

[Dave-1]

Afternoon @Petervn 

Cornice is a pain... Yep a pain. Tho once you get a corner right you will forget the pain!

I made up my own cornice shape and then had to cut the angles...  Garage lining for stud walls stage 2 (Cornice and skirting boards) is the project.

To add to ways to work out how to cut the right angle.

-Corners are not always exactly at right angles, so 45deg cut isnt going to work so easily. Maybe a 45 degree cut and then fill with plaster and sand will be an easier option. 

-Using an Empire 150mm Contour/Profile Gauge or similar helped me out sketching how it should be on paper.

-Practicing on offcuts, even thos its frustrating when you get it righ and then you realise its an offcut you still have managed to work the angles out

-I used my drop saw that has the angles on the bottom, much like your mitre box tho I found it more adjustable.

-I also used a copping saw for odd shapes tho that also took practice in cutting straight

I had a whole lot of almost the right angles and lots of "walk away" from the saw times when I could feel myself frustrated. I found tho I did keep getting closer to understanding the cuts and the knowledge of in or outside cuts  did end up helping.

Welcome to the community A good place to ask these types of questions! Cornice is a hard one to master but when you do you will look back at your earlier self and smile or laugh,

Dave