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Crown Molding

13K views 17 replies 13 participants last post by  NathanT 
#1 ·
I need help cutting crown molding it is driving me crazy.

I need to cut an outside 45 degree corner.

What are the angles I need to use to cut it?

Do I need to need to set the crown molding up on edge like it would go if being put up on the cabinet to cut it?


thanks
 
#2 ·
That's actually the easiest way I've found to do it. You didn't say what tools you have, but assuming you are using a CMS or a SCMS, you can stand the crown up like it sits on the cabinet or wall. The bottom of the moulding gets placed at the fence/base. Use a wedged support in front or back or both, and then cut your miters @ 45 deg. No bevel cuts to make, or figuring out which is upside down.

Here is another stand up method:








 
#3 ·
if your saw will allow for the height of the crown, i prefer the method shown in the illustration of cabinetman, however turn the crown upside-down, measure & mark the bottom & cut accordingly. just remember that now the left side is on the right & the right on the left. but like cabinetman said - just 45 deg now, no compund cuts. if your saw will not allow for the height you should have preset indentions at like 33 & 22.5, so just lay the crown flat. eric
 
#5 ·
George, I`m with you...back to cutting crown. Most miter saws have a (what I call) crown clamp. This clamp is designed to hold the crown at a constant angle while cutting. Now...there are basicly two types of crown...45 degree and maybe 60 degree. Place the crown inside a framing square...note the resting angle when the top and bottom edges have located on the framing square. This will tell you which type of crown you have or what degree. To cut a 45 degree outside corner...you need to think upside-down and backwards! In the saw, the crown`s bottom or wall edge will rest on the fence. And the top detail will be on the saw table...crown clamp holds the crown while cutting. Now, the edge of the crown that rests on the ceiling...may be back milled slightly...so make sure the bottom edge (that rests on the wall) is flat on the saw fence! To assist in making sure the crown is nailed at the proper angle...note the distance the crown occupies while in the framing square...out and down...make a scribing block and transfer that line too the wall and ceiling. Coping...will be covered second simester and compound miters...third! hope this helps... Rick
 
#6 ·
For all you guys that are using compound pre-sets and laying the crown flat...GOOD LUCK! It will work, but is more probmatic...especially if you get crown that might not be milled right. Plus, it is much slower! I have cut way too much crown! My crown saw of choice was a 15" Hatchai... Rick
 
#8 ·
For all you guys that are using compound pre-sets and laying the crown flat...GOOD LUCK! It will work, but is more probmatic...especially if you get crown that might not be milled right. Plus, it is much slower! I have cut way too much crown! My crown saw of choice was a 15" Hatchai... Rick
I have had absolutely no problem using the preset angles on the saw and laying the crown flat. Also no problem when cutting a 45 if the crown is setting in it's upright position.

I do keep a set of inside and outside pattern pieces just because It is sometimes a long period between when I am cutting crown.

G
 
#7 ·
I am in the process of doing some crown also. I bought a couple of books on it to help me out. Also bought one of these Amazon.com: Bench Dog 10-027 Polymer Crown-Cut Crown Molding Cutting Jig: Home Improvement. It seemed a little nicer than making my own jig and has worked great. I also bought a bosch digital protractor to find the angles of the corners since most corners aren't a true 45 degrees. It is a little expensive but I figured I would use it for other things and it has come in handy. So far it's been going pretty good. A good book helps alot when learning.
 
#9 ·
CMS-Compound Miter Saw
SCMS-Sliding Compound Miter Saw

The only problem with using the markings on the saw and laying the moulding down, that I have ever encountered, is changing settings and trying to get back to cuts that match previous cuts. I carried two saws, because once I started cutting crown, until I finished the crown I never changed the saw settings on the crown saw.

I learned to cut crown on a 15" Hitachi but once I learned how to cut it flat and on a compound saw I never went back to one. It's so much faster to cut flat.
 
#10 ·
Here is a tip for cutting crown, if ya-all promise not to spread it around.

To get lengths right, like between two 90 degree outside corners, cut two sample pieces. Cut a 45 on the left one and a 45 on the right one. As they sit on the wall cut them both off at 90 degrees, 10" long. I picked 10" because it's an even number, and I'm a simple guy.

Now, when you go to get a wall measurement, set the two pieces up so the miter closes up, and make a fine pencil mark on the straight end. From that mark to wherever the crown goes you can get a wall measurement from that corner by adding 10". If you do that on the other corner, you will have the dimension between marks that you can add 20" to.

You can cut the actual crown a bit heavy to fine tune the mitered fit.






 
#13 ·
I need help cutting crown molding it is driving me crazy.

I need to cut an outside 45 degree corner.

What are the angles I need to use to cut it?

Do I need to need to set the crown molding up on edge like it would go if being put up on the cabinet to cut it?


thanks
It may be too late but I found a chart on DeWalt tools web site while looking at miter saws there. This chart allows you to lay any type crown molding flat on its back and gives you the miter & bevel for every possible corner angle. Two adjustments on your saw, one cut and its done. My outside corners have been tight and very clean every time I use this chart.
 
#15 · (Edited)
When you have great, tip post a link, please

It may be too late but I found a chart on DeWalt tools web site while looking at miter saws there. This chart allows you to lay any type crown molding flat on its back and gives you the miter & bevel for every possible corner angle. Two adjustments on your saw, one cut and its done. My outside corners have been tight and very clean every time I use this chart.
It took me a while but iI finally found the chart you were referring to above. It's buried in a place you wouldn't think and search came up with zero. Here's the link: http://www.dewalt.com/featured-articles/cutting-crown-molding-with-dewalt-miter-saws.aspx
 
#14 ·
coping

I think i did everything right and it is still wrong

used 2 pieces of wood to check the angle of intersecting walls to establish the angle on the miter saw.
I used a bevel and a protractor and came up with 92 degrees.
when i cut two 46 degree angles it was open in the front
when i cut two 44 degree angles it closed tight
am i to measure the angle and subtract from 180 degrees
I have walls slightly out of plumb , ceiling out of level and walls not square
do i try to compensate for all this or just test cut miters and roll the crown into a good fit
also when i hold the crown in a framing square , i get anywhere from 3 1/8 to 3 and 3/8 projection. when i cut a 45 isnt the miter cut suppose to be the same projection .
I am a bit rust , but do have good hands and am very frustrated
i tried coping and no matter how sever the back cut i cannot get the top to close
please help
 
#16 ·
I think i did everything right and it is still wrong

used 2 pieces of wood to check the angle of intersecting walls to establish the angle on the miter saw.
I used a bevel and a protractor and came up with 92 degrees.
when i cut two 46 degree angles it was open in the front
when i cut two 44 degree angles it closed tight
am i to measure the angle and subtract from 180 degrees
I have walls slightly out of plumb , ceiling out of level and walls not square
do i try to compensate for all this or just test cut miters and roll the crown into a good fit
also when i hold the crown in a framing square , i get anywhere from 3 1/8 to 3 and 3/8 projection. when i cut a 45 isnt the miter cut suppose to be the same projection .
I am a bit rust , but do have good hands and am very frustrated
i tried coping and no matter how sever the back cut i cannot get the top to close
please help

Do you have pics of the results?
 
#18 ·
General Guidelines
What material is the crown made of?
Wood – Cope (unless painting)
MDF – Miter

Will the crown be stained or painted?
Stain – Cope
Paint – Miter

Adjusting for out of plumb?
Not a lot you can do about the ceiling except use a sander to trim the back of the crown or if it’s a lighter material bend it to position.

Coping, closing your corners?
Cope the crown in position. If you’re laying it flat then the top corners will never match because you’re ignoring the spring angle when coping.

92 degree wall – How to measure Miter?
Assuming you’re using a crown jig (otherwise becomes compound angles) you have the crown body to your left meaning you’re cutting the right edge of the crown.

The actual angle that you’re dealing with is 360 degrees, but your saw and the walls reduce it to a manageable 270/180/90. 270 is an outside corner, 180 is a flat wall and 90 is an inside corner.

Now picture a circle, a pizza works well for this. If the wall is greedy it takes up most of the pizza, leaving you with one quarter or 90 degrees. If the wall is a nice guy then it leaves you most of the pizza or 270 degrees.

The miter saw lets you decide if the wall should get most of the pizza or if you should. Equal (0 degree miter) is a flat cut. Unless you’re coping, sadly you’ll never use this setting, but then again life is rarely fair for you or walls.

The bulk of your work piece is to your left, meaning it will occupy the right side of an angle. We’ll stick with the pizza thing because it’s near lunch. So, the pizza is to your left and you want to be a nice guy so you give most of the pie to the wall by moving the miter to the left. If you’re feeling like a jerk then take most of it by moving the miter to the right. The exact opposite is true if the pizza is to your right, left to take more and right to take less.

At this time I suggest using a mimetic to help yourself out. I don’t have a good one so you can just scream “screw you wall” if you’re going to take most of the pizza (outside corner) or “okay, this time you get it all” if you’re giving the wall most of it (inside corner)

So, joking aside your angles are either 90 degrees of the circle representing an inside corner or 270 degrees for an outside. A flat piece is always 180. You’re either subtracting from that 180 to make an inside corner or adding to make an outside.

A perfect outside corner is 180+90 = 270
A perfect inside corner is 180-90=90

So if your inside wall is a little open, say the 92 degrees you had, the angle is 180-92=88. Divided by 2 your miter angle is 44. If the wall is just a bit closed, say 88 degrees then that angle becomes 46.

Outside corners work in the exact opposite direction. A slightly smaller than 90 degree wall means you need a bit more to 180 to make the angle fit. An outside corner that shows on a protractor as 88 degrees means the actual angle is 360-88 (occupied space) so 272. 180 is always fixed so 272-180=92. Divide that by two and you get a miter angle of 46 degrees. A corner that is a bit fatter decreases the cut angle to 44.

Other things to consider
If you’re using a painted pine or mdf you can always use caulk to close mitered joints. If it’s a stained wood things are a little more delicate. You can use stainable wood filler or a filler stick, but your corners have to allow for minor wood movement. Also, with an imperfect cope you still get one great view angle and one so-so angle. With an imperfect miter you get nothing but bad viewing angles.
 
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