Cutting Crown on flat Inside Corner???

[Carroll Courtney]

Guys I have a 12" Dewalt compound miter saw that I need to cut some crown molding on the flat.I tilt the compound to 45 then the miter to 45 and it is way off.The crown is from HD so its nothing special,but I guess there is a formula for cutting inside corners while laying the molding flat on the saw.Is there a chart that shows the angles that I need to setup the compound and the miter to get that perfect inside angles?Sounds confusing but I hope someone knows what I am talking about

[Leo Graywacz]

Why are you cutting it on the flat when your 12" saw is more than capable to cut it nested?

If you insist on cutting it on the flat you need to know the spring angle of the molding. Then you can look up in a chart what to set the miter and bevel at.

But the easiest way is to nest the crown in the saw and just cut the miter.


https://www.youtube.com/watch?v=9QpnWgGNtOk

[Bradley Gray]

If the crown isn't too big, set the moulding on the saw as it will be installed only upside down and cut at 45 degrees.

For best results cut a cope after mitering.

[Phil Mueller]

As said above. On inside miters you can run one side square to the wall, then miter and cope the adjoining molding.

[Leo Graywacz]

You can miter the inside corners too. But it's much harder to get a nice joint because when you nail it together it usually moves since drywall isn't that solid.

I miter the crown for an inside joint. Then I cope it using a hand coping saw. Then I use a Dremel with a sanding drum to tune it in perfect.

[Sam Murdoch]

Here is helpful link on the topic. http://www.thisiscarpentry.com/2015/04/03/installing-crown-molding/

[Justin Ludwig]

+1 on Leo's comments.

I built plywood outfeed tables for my miter saw stand so I can screw nesting boards in place. I never have to press the crown and make sure it's nested on the proper spring angle this way. Use a 2' offcut of crown to set the nesting board, secure it anyway you can. Get after it. The locals 'round here look at me crazy when I set up. Then they see me measure entire rooms or an entire kitchen of cabinets - cut everything in one trip then install it. I sometimes have to make a trim to shave a piece or to compound a piece on a jacked up wall. Blows me away to see guys take 1-2 measurements to the saw at a time - not hobbyists, but pros.

[Martin Wasner]

I rarely cut crown just using a miter, but I also hate big blade saws. I think it's easier, doing a compound cut, but to each their own. You're not fighting with the material as much when you've got a 16' long stick trying to flap and roll around.


Setting the bevel and miter at 45º won't get you there obviously. First, what kind of crown? Is it 38/52, or 45/45?

For 38/52 on a 90º corner it's 31.6º miter, 33.8º bevel.
On 45/45 on a 90º corner it's 35.2º miter, 30º bevel.

There's calculators available online for other angles that do the trig for you.

[Leo Graywacz]

Last crown I bought at HD was 37/53 357462

[Justin Ludwig]

I rarely cut crown just using a miter, but I also hate big blade saws. I think it's easier, doing a compound cut, but to each their own. You're not fighting with the material as much when you've got a 16' long stick trying to flap and roll around.


I don't even try to fight them. Unless it's crown for a room - I'll cut it down to +1" on the flat, then nest it. Sometimes there are bows in the crown that cause it to pull/push from the nesting board - cut the piece long from your mark and get the offcut out of the way. Proceed to trim to mark.

I don't like laying my saw over for repeated 45* compound cuts. That's where the big blade stares back at me. But like you said, "to each their own."

[George Bokros]

Last crown I bought at HD was 37/53 357462

I found the same thing. I don't understand why HD crown is at an odd angle. From lumber yards it is either 38/52 or 45/45.

[keith micinski]

I have never understood why anyone would want to fight cutting crown anyway but flat. Making jigs and blocks helps but doesn't always make it perfect and I can't seem to find any advantage to cutting it this way and several disadvantages. 33.9 and 31.65 aren't any harder to find on my mitre saw then 45 is.

[Leo Graywacz]

I don't fight it at all, as a matter of fact, it's a breeze. I am constantly adjusting the crown miter to fit the corners. It's a lot easier to swing the miter to 44 degrees than it is to figure out the two angles for miter and bevel. By the time you use your chart or calculator, I'm installing my pc of crown. I have a Bosch angle finder and I usually bisect that angle for the miter. It makes for a very tight joint which is necessary when you are using prefinished crown, not so much when it's going to be painted with a brush afterwards.

I don't need any jigs, I just nest the crown according to the flats on the crown's backside. Last couple of times I've used a nesting jig and it's made it easier. The only time I ever do crown on the flat is when the crown is too big for my saw. Like the 8" crown I did a few years ago. And the outside miter was very hard to do because it was no where near 90º.

[Jim Dwight]

I recommend Ron Paulk's you tube videos on crown. I had done a few rooms before watching it but learned enough to do the last little bit far easier. He cuts it nested, not flat, and recommends a few simple jigs you make of scrap plywood. Crown can normally be installed at a range of angles and it is important to be consistent. So Ron has you pick a distance along the wall and ceiling that you want the crown to sit. Then you make a board the distance out on the ceiling for setting the piece you will hold against on the bed of your miter saw. You make another piece to hold the crown up at these distances while you nail it. And he also uses a U shaped jig for the cope cut. It's amazing how quick Ron copes with a jig saw. It's worth watching these You tubes even if you are somewhat experienced.

There are tables of the angles available over the internet but it will not solve the need to install the molding consistently at the same angle. Nor will it help you cope. A cope deals with corners a little off from 90 better than a miter. It also deals with movement from the walls moving or the molding shrinking. Outside corners get mitered, glued, and clamped until the glue is dry. Inside corners get coped. Walls without backing to nail into get a piece of wood glued to the drywall to nail into. Practical solutions to the problems that come up in every crown job.

[keith micinski]

I recommend Ron Paulk's you tube videos on crown. I had done a few rooms before watching it but learned enough to do the last little bit far easier. He cuts it nested, not flat, and recommends a few simple jigs you make of scrap plywood. Crown can normally be installed at a range of angles and it is important to be consistent. So Ron has you pick a distance along the wall and ceiling that you want the crown to sit. Then you make a board the distance out on the ceiling for setting the piece you will hold against on the bed of your miter saw. You make another piece to hold the crown up at these distances while you nail it. And he also uses a U shaped jig for the cope cut. It's amazing how quick Ron copes with a jig saw. It's worth watching these You tubes even if you are somewhat experienced.

There are tables of the angles available over the internet but it will not solve the need to install the molding consistently at the same angle. Nor will it help you cope. A cope deals with corners a little off from 90 better than a miter. It also deals with movement from the walls moving or the molding shrinking. Outside corners get mitered, glued, and clamped until the glue is dry. Inside corners get coped. Walls without backing to nail into get a piece of wood glued to the drywall to nail into. Practical solutions to the problems that come up in every crown job.


Unfortunately you must be a much better trim carpenter than I am because trying to get a 12 foot long piece of crown nested perfectly in any saw has never been anything but a nightmare for me

[Justin Ludwig]

Unfortunately you must be a much better trim carpenter than I am because trying to get a 12 foot long piece of crown nested perfectly in any saw has never been anything but a nightmare for me

Nesting board. Period. I threw away the metal extendable arms on my miter saw stand. Built plywood outfeed tables with adjustable feet for leveling. I can screw the nesting board to the tables. I keep a piece of 1x6 pine screwed underneath the tables as my nesting board. When it's time for crown, unscrew, mount to tables with a small piece of crown nest and I'm off to the races. It makes crown cutting a breeze.

I've got other tricks for transferring the measurements to crown on outside corners. I also keep a 16" ruler at the saw for making all measurements with that instead of trying to handle a tape. Works really great when you get down to <18" of crown on the saw.

[Mark Wooden]

If you do any amount of moulding & trim work, you should have a long enough saw bench, or at least stands, to allow you to cut a piece of crown, base or chair rail longer than eight feet. I cut 14'-16' regularly.
Finding out that the big box store's moulding has a different angle on the back edges shouldn't be a surprise, the stuff comes from some factory (probably overseas) who has never put up a piece and has no idea what the angles relate to, i.e walls and cielings and have ground knives off some pretty ambiguous drawings. You can still install it at the same angles as the better mouldings available at lumber yards though.

Crown has projection- how far out from the wall- and drop -how far down from the ceiling. Measure your stock with a (good framing) square to see what those dimensions are for a good fit. Keep those as a constant.
Make the bed of your saw the ceiling, make the fence of your saw the wall. If the fence isn't tall enough, screw a 3/4 " aux. fence to it to get the height. Make a pencil mark at the bottom of the crown on the fence. Use that mark to keep your moulding in the same place for all your cuts. After a while, you'll learn to 'roll' the crown up and down over/under the fence marks to compensate for various wall and corner conditions.
I have cut crowns 'on the flat' but find that sometimes the bottom of the moulding is up against the fence and I can't see the cut mark- I measure at the wall so I mark the inside of the miter on the stock. And laying flat, I find it difficult to move the saw through two axes to tweak a cut. But to each their own.

For coping, I make a simple 'L' cradle with a stop to hold the moulding at the angle it will sit at installed and cut my copes straight up and down with a coping saw. This makes for a good butt joint-which is what a cope really is- and not some hollowed out, weak and crushed fit. I also only cut into the face of the moulding to ensure a clean joint.

I have a Collins coping foot, it's great but I get a better job when using a coping saw, so I reserve the jig saw for paint grade where a small tooth nick can be caulked. And because I know how to cope and am practised , the jigsaw isn't really that much faster, if at all. But, admittedly, less tiring.;)

[Mel Fulks]

Mark is certainly right. But I've never seen any old crowns that did not bed at 45 degrees. For good pediments I refused to use any modern crowns. For one thing, if pediments are made the old way using crown and rake the rake is as flat as a piece of sheet rock to meet with modern crown.

[keith micinski]

Nesting board. Period. I threw away the metal extendable arms on my miter saw stand. Built plywood outfeed tables with adjustable feet for leveling. I can screw the nesting board to the tables. I keep a piece of 1x6 pine screwed underneath the tables as my nesting board. When it's time for crown, unscrew, mount to tables with a small piece of crown nest and I'm off to the races. It makes crown cutting a breeze.

I've got other tricks for transferring the measurements to crown on outside corners. I also keep a 16" ruler at the saw for making all measurements with that instead of trying to handle a tape. Works really great when you get down to <18" of crown on the saw.

So in your scenario I have to build outfeed tables, a nesting block, and then set all of this up. I'm still clueless in how this is easier then using my existing mitre stand with extensions and moving my saw to the two preset detents built in to cut crown on the flat. Any adjustment that needs to be made to adjust for an uneven corner apply exactly the same way they do if I was nesting it. Oh, I also have to store these outfedd tables somewhere when I'm not using them.

[Justin Ludwig]

So in your scenario I have to build outfeed tables, a nesting block, and then set all of this up. I'm still clueless in how this is easier then using my existing mitre stand with extensions and moving my saw to the two preset detents built in to cut crown on the flat. Any adjustment that needs to be made to adjust for an uneven corner apply exactly the same way they do if I was nesting it. Oh, I also have to store these outfedd tables somewhere when I'm not using them.

Yeah. Those tables also serve as work surface and I can set my crown on them. Uncut crown on one side, cut crown stacked on the other. And I put hanging nails on the underside 2x4 supports to hold tools. It's another one of my ugly bettys. It used to serve as my primary cutting station when I started my cab biz. Now it's just part of the road crew.

You don't have to make nesting block with the tables- it's just scrap 1x material or plywood scrap. If you stick with your current retractable arms on the saw stand, you have to make is a nesting board that will screw to the back of your miter saw (mine has factory holes in it). Adjust the out feed arms to match the height and you're all set. The bottom of the nesting board (ceiling part of crown) needs to be wide enough that you don't cut all the way through it when making cuts.

It may not be easier for you. It sure simplified my life. Setup takes only a couple minutes to level everything out. Storage could be a problem for some, but the legs can be designed to fold into the tables.

Sorry if I was sounding pushy. I'm the worst for coming off in a manner that implies: "my way is the only way"

[Larry Edgerton]

I do it both ways. The best trim guy I ever hired cut all of his crown laying down, and his work was second to none. I like it nested, but will do it the other way if it is taller that the saw fence on my Hitachi 15". I just use blue painters tape on the chop saw table put on at 45 on each side, that way if I need to compensate I can shift it either way.

On thing I did come up with for working alone is a bracket that hooks on a screw in the hollow behind the crown. It is 1/16" steel, lays flat on the wall, comes out 3/8" and then extends up on a 40 degree angle. There is a slot kind of like a keyhole slot on the wall section. You drive a screw into a stud, rang this bracket on the screw and then set your crown on it to support that end, work about half way to the bracket and then slip it off of the screw head and finish the crown into the corner. I made three sizes for different size crowns. Works slick. I usually install it about two thirds of the way down from the corner I am starting on. The screw just stays there.

I use a Collins coping foot on large crown, coping saw on smaller stock. I always cope inside corners.

[Martin Wasner]

I use a Collins coping foot on large crown, coping saw on smaller stock. I always cope inside corners.


I've tried gadgets. I've settled on just using a jig saw freehand and a belt sander on copes. 99% of the time I cope inside corners, the only time I don't is if it's a tiny return. Coping gives you options that mitering doesn't as far as being able to roll the crown around and still maintain a good looking joint.