Back To The Coping Issue...

King of Crown

I just ran into an interesting situation today I was installing 7 1/4 inch stretch king George crown, and realized that the profile is almost impossible to cope. It has a raised area on top that actually drops and then comes back up. That is probably not a good explanation, but one of the details is instead of being half of a circle, it is actually 5/8ths of a circle. I Will try to take some pictures and post them, but has this happened to anyone else before?

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clampman

Yes. Many times.

King of Crown

Did you continue to cope, or mitre?

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Toothpick

King I think I know what you are trying to say, not that my answer is going to be that much clearer. If I am understanding this right you have a part of the profile that goes past "level" and going back down. I run into this once in a while and what I do is cope like I normaly would, then hold the coped piece as close as you can to your previous piece. At this point it's not fitting of course but then here is the trick, mark a line or score a line with your knife on the previouse piece and then chisel out the "offending" part of the crown until the coped piece fits, the chisled area will be hidden behind the cope. First time you do it may take a little bit but done right it will look perfect. Clear as mud huh?

clampman

It depends on the profile and the size of the molding what I decide to do. If the crown is a really large one and difficult to miter, I will often do as Toothpick describes. Basically, what he is doing is cutting a mortise into the existing piece on the ceiling in exactly the shape of the profile of the coped piece AND in exactly the position on the existing piece where the coped piece will have to be for the entire profile to fit properly.

There is a way to cheat to make the above easier. And that is to miter the first piece you put up, but about 3/8 inch too long. That way, when you stick your coped piece up to the first one to see where you need to mortise the first one, you can get the coped piece much closer to the existing one so you can mark a line on the first where you need to mortise it out.

Also, when you do it this way, you do not have to cut nearly as much out with a chisel or knife because there is only 3/8 inch of material to remove.

But which way I select depends on the difficulty of each method, and that in turn depends on each particular crown molding size and profile. Generally, I prefer to miter uncopable crowns - especially if the uncopable section is a large one.

One thing to remember when using the cope and mortise technique is that you will need to have both pieces on exactly the right spring angle before marking for the mortise. If one is wrong, you will have the mortise in the wrong place and there is no way that rocking the crowns will work to fix it.

Here is a link to a video I made a while back showing how to recognise uncopable crowns for anyone who doesn't know what we are talking about.

I am not sure if my explanation is clear enough or not and would appreciate feedback if someone does not understand how to recognise uncopable crown after watching it. You will also need a high speed connection to watch it.

http://www.miterclamp.com/videos/uncopable_crown.wmv

Thanks.

Jimc

King of Crown

hey, great! thanks guys. that is kinda what I ended up doing, but Clamp, you miter/cope method sounds like a true winner.

Unfortunately, these walls and ceilings are like the ocean, and fortunately, i started with the paint grade, and the ceilings are 12' tall.

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fishmusish

Yes, most of us have encountered that crown that does a direction reversal, making the crown somewhat impossible to cope correctly. I have always coped all of my inside corners on ALL my work...this crown came into my life about7 yrs ago....It was paintgrade...so I cheated,I mitred an inside corner for the first time in my career,Painfull, being a purist.As a fly tier and fisher....bastardization of principle is sometimes required to move through nuances undiscoverd previously...Good luck