Cornice 45º

[Gary0]

My kitchen project has been stalled for some time now and the reason is the cornice I bought for the top of the wall cabinets, The straight bits went fine, but where I needed a 45º cut for the corners I got problems.

I tried a common mitre box but the problem is that the cornice is effectively standing on a thin strip and there is no easy way to kniw one is holding it upright and steady, and ensure a clean accurate cut. The cut I got didn't fit the second piece of cornice properly and threatened hours of file/sand & retry.

I spotted a Coveasy guide at the Screwfix site and got one to see if it would solve the problem, but it clearly is for a specific coving shape only and isn't helping (I have coving to do when I get around to it so it won't be wasted, but the cornice is still an issue).

So I'm stuck again.

Can someone suggest how the job is done so I ensure it is upright as it will be in situ to get an accurate cut first time in the cornice please ? Is there a jig out there which allows this to happen with ease, or is there some other way to achieve it ?

Thanks in advance.

 

[big-all]

your miter box/saw needs to support the base and back fully at the contact points and you need to sit flat in the box
or use a compound miter saw and cut flat

 

[Gary0]

Thanks.

Maybe I'm missing something obvious but I don't see how a normal box is of help. There is no vertical on the cornice to push against the back, were it otherwise there'd be little problem. And the only horizontal is about 20mm wide, so it's like trying to keep a pencil up on it's point. Apart from that it's all slope & angle, which is why the first cut attempt was not good.

I was rather hoping there was something one could clamp it in and know it is rigidly in the correct orientation.

 

[big-all]

the answer is you cannot cut coving unless its fully supported in the normal orientation off 45% in a miter box or flat in a compound miter saw

 

[Gary0]

Thanks. I think that is the nub of my question. How to achieve this. In the past when I've only had to cut a 45º in what was basically rectangular material the need to clamp it somehow has never arisen.

 

[Harbourwoodwork]

You need a chop saw with fine blade,do the cut with the cornice flat,Google compound mitre cuts that gives all the possibilities of angle of cornice mitre and bevelcut's

 

[big-all]

http://www.dewalt.com/featured-articles/cutting-crown-molding-with-dewalt-miter-saws.aspx

 

[Gary0]

Cheers, I'll check it all out and hopefully learn about it all. I'll be back if I still have questions.

Having looked at it a few times I suspect I should go out and order some "scrap" for pretesting. It seems to work for them, but I think I need to see for myself it works when I do it.

 

[Gary0]

Ah shoot.

I now see the top video is the relevant one, the lower one seems to be for some flat moulding. The trouble is I only recently treated myself to a mitre saw, a PCMS210L Performance Power, and as far as I can see it doesn't have this high fence needed; so I'm back to the cornice wobbling on it's point again, only this time with a power saw trying to make the cut.

(Actually the video shows a flat area at both base and top, in fact the cornice I'm cutting has only a narrow strip of flat at the base, and the top is rounded.)

Is my only option to treat myself to yet another compound mitre saw with such a fence ? Does that mean I'm left with Dewalt only ?

Thanks.

 

[Gary0]

To clarify the issue here are 2 photos.

The instruction video shows a flat area at both ends so one has a fighting chance of positioning it correctly as it shows with one flat on the base and the other against the wall. But the second image shows the shape I have where there is only one small flat edge and the other end is rounded.

Even against a wall (should I find one tall enough) it is clearly subject to not being held quite right, since the rounded end adds nothing and experience tells me one can think the one flat bit is correctly flat against the wall or base, but from experience know it can turns out that it wasn't.

Is there any further help anyone can suggest ?

http://i32.photobucket.com/albums/d36/bright_/corniceinstructions_zps161e501c.jpg
http://i32.photobucket.com/albums/d36/bright_/temp_zps2947afbc.jpg

 

[Deleted member 174758]

as far as I can see it doesn't have this high fence needed; so I'm back to the cornice wobbling on it's point again, only this time with a power saw trying to make the cut.

So why not attach a piece of flat material to the back fence to get the high fence you need? You'll spend for ever looking for an off the shelf saw with that type of fence..... To support the front edge you'll also need to make-up some form of stop. Alternatively you could just buy something like this which will hold the material consistently

 

[Gary0]

Hi, thanks for the reply.

I had considered adding a piece of taller material into the mix, but was concerned how easy it was to hold two pieces in place and pay attention to ensuring my fingers were nowhere near the blade. I hadn't attempted it yet in the hope there was a trade solution I may not be aware of. However that mitre jig looks very interesting. It looks as if the correct angle can be set up and then trusted during the cut. That plus a tall piece at the back as well, might be the solution providing the 80mm proves large enough. I'll have to try it. (May search the net for similar also.)

Thanks for that.

 

[Gary0]

Just to say I've been staring at this cornice for a while and I think I may have cracked the big secret.

The cut out at the back, which I took to be there solely for giving a flat surface to put the screws in. It looks as if it can be used for a second function.

Turn the cornice upside down. Then one can place a square piece of "scrap" wood (or metal or whatever) into that cut out, presferably so the cornice no longer rests on the base in order to wobble.

Press down on the cornice to hold it there tight. It looks as if one should be able to hold it all steady at exactly the right angle, with no (or little) wobble. At least that's the hope.

(It would need a rather tall mitre saw box though if the saw is going to get into the guide before contacting the cornice.)

I'm keeping my fingers crossed and I'm going to check that tomorrow.

 

[Harbourwoodwork]

the answer is you cannot cut coving unless its fully supported in the normal orientation off 45% in a miter box or flat in a compound miter saw

 

[Harbourwoodwork]

http://www.dewalt.com/featured-articles/cutting-crown-molding-with-dewalt-miter-saws.aspx