Cornices

[angelwing]

Hi everyone,

My hubbie and I are renovating an 1890 two storey victorian home, (its ours), one problem I'm having is getting my mitres correct on the decorative cornice. I've tried with a wooden mitre box, also the little plastic mitre from CSR gyprock, but I'm still getting a big gap.

Can anyone give me some advice !! :confused:

[arose62]

How big is "big" ? Cornice cement can do a fair bit of filling...

The tips-n-tricks I have re: cornice are:

1) don't worry about the squeeze-out of the cornice cement. Just get the cornice up there and glued.

2) don't sand. Once the cornice is up and stuck, use a paintbrush dipped in water, and just 'paint' over the joins and edges. Don't have a soaking wet brush, just wet enough that it smooths the cement without washing it away. Saves getting sanding dust everywhere, and gives a lovely smooth finish.

3) I found the little red plastic thingy (LRPT) a wonder! Took a couple of practice cuts to get my head around the back-to-front and upside-down orientation to make the cuts work. I ended up keeping a set of offcuts labelled for an inside corner, and outside corner, and checking which way the LRPT should go before cutting.

4) Concentrate on the corners which you see when you first enter the room, or the ones which cop the most light. We had a couple of rooms with no right angles, and managed to accumulate the errors into a corner over a cupboard, so it's not noticeable.

Cheers,
Andrew

[namtrak]

Can be a frustrating exercise. Take a piece along to a local plaster supply mob. Someone there will show you in a jiffy.

[Tools]

If the gap is on thre top or bottom of the cornice,you probably don't have the cornice positioned correctly on the wall.Check what the distanece down from the ceiling and away from the wall should be and chalk these two lines first.

Tools

[Wildman]

The best way to use the mitre boxes is to put the cornice into the box in the same way it will sit on the roof, ie upside down so when you look down on the top of the mitre box, you are looking at the back of the cornice rather than the display side. My mitre box seems designed to work that way and it gives perfect cornice mitres every time. Much easier than the upside down back to front you have to think if you put the cornice in the other way.

Cheers
Ben

[ThePope]

Both Boral and CSR have brochures on fitting cornice, have a read they may help out.

[rod1949]

The best way to use the mitre boxes is to put the cornice into the box in the same way it will sit on the roof, ie upside down so when you look down on the top of the mitre box, you are looking at the back of the cornice rather than the display side. My mitre box seems designed to work that way and it gives perfect cornice mitres every time. Much easier than the upside down back to front you have to think if you put the cornice in the other way.

Cheers
Ben

Go Wildmans way. Also remember, it will be highly unlikely that the wall corners will be square.

[angelwing]

Thanks for the tips.

The gaps I spoke of were in the corners of the cornice, after the mitre cut, not under or above, having no prob's with that bit.

The cornice is 90cm.

I will try your ideas, let u know how I get on.

Bye for now.

[Ashore]

Helped my father with some 1860's terrace's in sydney quite a few years ago and found there were no rt angle walls they were 88 deg or so or 94 deg and some of the cellings wernt square either , so a 90 deg mitre box was no use at all, dad got them freehand , would measure the angle then allow a bit and filled any small gaps

Drove the carpet layer berko as well


Rgds

[Markw]

Had some patching to do of the cornice where a floor to ceiling wardrobe had previously been fitted, and didn't have a mitre box - I used the SCMS instead.

Yes it blows a bit of plaster dust everywhere but I used it outside and cleaned immediately after use. The 25mm finger of cornice was just perfect (except CSR/Boral don't make the exact same size any more - slightly smaller).

For the one off piece it was just the right tool.