cornice cuts

[mic-d]

I did some timber cornices the other day and was not happy with the internal corners since they opened up a little - same problem as mitreing internal corners on skirts. So rather than using the magic marks on the mitre saw to make the compound cuts, what angle do you set the saw at to do scribed cornice. One section will be butted up to the corner, the other will be cut at 45º and bevelled at ???º to give the scribing line for the coping saw. But what is the ???º angle???:?

Cheers
Michael

[rat52]

The 45 deg cut gives you the line to follow for the coping saw and you under cut so you get a point on the timber edge to bruise into the other piece.

Difficult to explain without pictures which I may be able to do on sat (I'm in my PJs now and it's too b--- cold to go out) if no one else can explain it better.

Michael PM me if you want pics.:2tsup:

[mic-d]

Hi Rat, the 45º cut allows the cut to follow the installed cornice face from ceiling to wall, but the bevel at :? º is the one that gives the line for the coping saw to follow I think.

Cheers
Michael

G'day Rat, woke up at 3 this morning and thought what I wrote was BS! I think the cut to follow the cornice will be the magic angle on the saw and then as you said the 45º bevel will give the line for the coping saw. Sound right? Thanks for the offer to do some photos.

Cheers
Michael

[rat52]

Mic-d,
I hope these pics help,:D
1/ shows the miters off the saw
23&4 show under cutting
The last shows how it fits

[rat52]

Last pic hopefully shows the undercutting

[mic-d]

Hi Rat, thankyou for the photos which are completely not the way I thought to do it. So I'll take a bit of time and digest this.
My cornice was the 'hollow' back one, not the solid one like your example and I was laying it flat on the saw which is different to your solid cornice, so I'll see if I can work up a method for this too.

Cheers
Michael

[rat52]

Mic-d,
flat on its back is wrong. There should be 2 small flats close to the edges and these are what you place on the base and back of your mitre box/saw.

Imagine the back of the cornice filled in like my scotia in the picture.

If you are using 50mm cornice then draw a line 50mm in from the back of the mitre box on the flat and 50mm up the face of the back. These are the lines to place the edges of the cornice on to do the cut.

Dam, I'm sorry if it doesn't make much sense but I dont have any cornice to take a pic of.:~:?

I'll try to think of something tomorrow.

[peter_sm]

I just finished doing cornice in our laundry and bathroom. 'Croydon' style and the best thing I did was spend the $20 on a mitrebox. The one I got specifically lets you cut the cornice upsidedown, which is actually the position it would be in once put up. It has steps for the different thicknesses of cornice to sit in.

Hmm hard to explain without pics!

[rat52]

Michael,
here are the next series of photos I hope will explain how to cut scribes.

1/ laying flat is not the way to cut the mitre
2/ this is the way the timber should be placed
3/ correct cutting of the mitre prior to scribing with the coping saw
4/ the final fit

Peter I would be interested in seeing a pic of that mitre box as I have never seen one that does reverse cuts

[billbeee]

Rat52,
Excellent photos, the hardest thing I've found is explaining the undercut. Sometimes I think it is better to say cut square and they will work it out from there.

Mic-d,
Lying it flat is what the Americans do when they are trying to scribe large cornices or as they call them "Crown Moulds". Google "crown mould angles" and you will get heaps of calculations and methods. Each one more confusing than the last. The only way to do it is as Rat says. Just imagine the drop saw bed as the ceiling and the saw fence as the wall. PPP.
Cheers
Bill

[mic-d]

Many Thanks rat and Bill.

Cheers
Michael

[rat52]

Mic-d,
I'm not a very good teacher because I keep forgetting things like when as an apprentice learning how to do scribing I carried a small offcut in my nailbag so I could mark the cuts left or right