# coping crown



## mencheman (Sep 24, 2009)

I have ***** # 185 Crown molding with an actual 3 1/4 projection and from ceiling to bottom 3 3/8
According to the molding book it should be 3 1/4 x 3 x 31/4

how ever when I turn it upside down and backwards to cut a 45 and expose the profile for the left side of an inside corner I cannot get a good cope. it is open by 1/8 on the top.
When it sits on the miter saw up and backwards , it measures 3 1/8 x 3 3/8. 
i took it to a friend who is a cabinet maker and he cut it as it would lie against the wall and ceiling only with the profile towards the fence of the saw- a very difficult way to hold the piece.

I cannot get to the bottom of this .
Can anyone help. I watched the videos and i know I can follow the profile of the crown very well and i have a severe back cut 
It seems to me the angle is keeping it open at the top


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## firehawkmph (Apr 26, 2008)

Mench,
Whenever I cut crown, I use a plywood accessory fence I screw to my fence on my miter saw. It is basically L-shaped and lets me tack a small stop on each side of the blade to hold the bottom of the crown as it sits in the saw. It sounds like your cut is off just a tad, or when you are putting it up at the ceiling, you may be rocking the molding just a bit. That will open up a gap. I usually take a framing square before I cut anything and put the crown into the inside corner of the square so both flat edges are sitting flat on the square. That gives me a proper measurement for the height and projection of the crown. Then I set my stop on the saw to hold it precisely in that position. Check your saw and make sure it is in tune. A 1/2 degree off will definitely show up. Lastly, I used to cut some scraps of the crown with slightly different angles on them and test fit the corners. Now I use a plastic adjustable protractor and measure the corners with it. Coping crown takes a lot more practice and patience than coping base for instance. Buy some extra, take your time and take a break whenever something doesn't fit right and try and figure it out. 
Mike Hawkins
"If it was easy, everyone would be doing it." :wallbash:


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## mwhafner (Jan 16, 2009)

Are you using some type of crown stops when cutting? It sounds like you have the angle slightly off, as Firehawk stated.

Here is the trick I use, but I am sure that others have their own. I cut a measuring stick that I use to both set my crown stop and mark the ceiling.


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## plyboy (Aug 15, 2009)

*You are the one*

The most important thing is to install the first piece at the same angle you are cutting the coped piece to, not what it says in the book. (What book?):huh:

I make a mock up 90deg. joint, backnailed and glued about 10" long in each direction. I hold this up to the ceiling at each corner, and pencil along the bottom where it lands on to the wall. Remember, a lot of times, the mud will slope down in a corner, throwing off your measurement. The mock up jig shows it pretty much how it will end up. May be less, may be more than the actual number you are using.

A sloppy drywall mud job will frustrate you needlessly. The room could be perfectly 90 degrees, except six or eight inches from each corner. This also answers the question, "why cope?"

Use the mock up for up and down marks, u can't go wrong. A chalk line on the wall between the mock up points will also help you line up scarfs on long runs. Chalk the line 1/8" higher, cover it up with the crown.

The most important thing is how it looks, not how the numbers work. If the numbers don't work but it looks good, go with it. You will have plenty of time in retirement to ponder the why or why not of it.:laughing:


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## NathanT (Sep 11, 2009)

My advice is to cut it with the profile facing out, upside down and in position. If you're going to cut flat then upside down with profile facing up. If it's in position, you only worry about the miter angle, if flat then it's miter and bevel. 

From your spring angles it seems like you have 38 degree sprung crown so your settings for a 90 degree wall would be 31.6M(iter) and 33.8B(evel). In position it's a simple 45M. Also, in position you don't have to worry if you have a miter saw with only one bevel setting.

This site is somewhat valuable, as long as you don't mind the ad-vomit.

http://www.installcrown.com/

Valuable TOH video on coping: http://www.thisoldhouse.com/toh/video/0,,1632379,00.html


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