I want to make my own cornors for crown molding but need to know the angles to cut them?

Question

inside and outside cornors to install along with the crown molding. I need instruction on how to make them, such as the angles

Answer 1

If you have a chop saw or compound miter saw, it should have the marks or a stop for them so you can turn the table to cut at that angle.

I can't remember right off hand, but it's somewhere around 32.5 (maybe 37.5?) and 22.5. It's close to those numbers, but I can't tell you exactly.

If you dont have a chop/compound miter saw, stop by somewhere that sells them and check out the marks.

Again, you cant cut at just one angle though. You need the pieces to have a bevel and be cut at an angle both....and the easiest way to do this is with a compound miter saw.

Whoever tells you it is a 45 degree cut is wrong. You probably already knew this or you wouldn't have asked. They don't realize that crown moulding doesn't lie flush against the wall, it spans to the ceiling as well. You know this, they don't. Don't pay any attention to them.

Here you go, found it:
Cutting Crown Molding Compound Method (Flat)

Inside corner
Left Side:

Top of Molding Against Fence
Bevel Set at 33.85º
Miter Right at 31.62º
Save Left End of Cut

Right Side:

Bottom of Molding Against Fence
Bevel Set at 33.85º
Miter Left at 31.62º
Save Left End of Cut

Outside corner
Left Side:

Bottom of Molding Against Fence
Bevel Set at 33.85º
Miter Left at 31.62º
Save Right End of Cut

Right Side:

Top of Molding Against Fence
Bevel Set at 33.85º
Miter Right at 31.62º
Save Right End of Cut

Answer 2

It would be easier if you had an electric miter saw (some are calling it chop saw). The truth of the matter is - there are no square corners. So instead of a square, get an angle finder, sold at Lowes if those stupid people know what it is. It looks like a square, but the blade that would normally show only 90 degrees, moves, so you can set it up there and find the angle, tighten up the angle finder, use a protractor and find out what that angle actually is, and divide it by 2. Working on hexagonal areas or pentagonal areas involves some more math.

For a test, get a piece or two of paint grade crown molding and play with it.

Remember one thing for sure, you cut it upside down and backwards. Turn the molding upside down against the fence of the saw and then tighten the moulding like it would fit on the ceiling, but the part that would fit on the ceiling is on the floor of the saw, the part that would fit on the wall would be against the fence. There are some books which will help you.

Crown is expensive, so reduce your screwups to a minimum or you will have an abundance of kindling - expensive kindling.

Rent an 18 gauge nail gun, battery if possible, put the board up there and pop it in.

Do not push butt ends of pieces of wood together when the piece that you have is not long enough. Cut both ends at 45

and get them as tight as possible on the wall. nail about an inch away from the ends to keep them from possibly splitting.

This is not mere carpentry, it is an art, but it can be learned rather quickly.

If you are to paint, use paint grade and slight problems with the corners are not a problem becasue you can caulk then in. Caulk all of your nail holes and smooth out the caulk with a clean damp rag. If you are trying to finish it natural, use the higher grade of crown, but then your corners have to be almost dead on.

Answer 3

The outside corners can usually be cut anywhere from 45 to 48 degrees to allow for imperfections on the wall. For the inside its a bit more work involved-

First make one side of the corner a straight cut that will butt directly up against the wall that is perpindicular. On the other side you will have to do what is called "back mitering" which involves cutting a 45 degree angle on the trim with the cut side facing the same side as the front of the trim. Then take a coping saw and cut an opposite 45 degree angle while following the profile of the trim. Once you put this piece in place the two sides of the corner will match perfectly regardless of whether or not the wall is straight.

Answer 4

crown molding sits at 2 angle typically
you 1st need to know which of the 2 it sits on
next it's best ot make a jig so that one agnle is set you will always cut crown bottom side up and then at 45 ( not cutting it flat ), this means a good 10" or 12 chopbox saw can be used instead of a compound cut saw.
never assume you outside and inside corner are true 90s, they rarely are.. eith get an agle finder to divide the corner accurately, or cut 3 small sets of in/ out corner templates, at 44, 45 and 46 degree, this will pretty much take care of most of your guess work in figuring out your angles. also it's a good idea to neail or screw up 1x pine backing ripped to less than the backside dimension of the crown, this will eliminate looking for backing, especially if you splice a run, it alos need far less nail and you can set 1 nail in the center as opposed to 2 sets.


http://www.extremehowto.com/xh/article.asp?article_id=60354

http://www.installcrown.com/

Answer 5

I don't think you will find a better answer than the one from Jared F. I might suggest that when using this method you take short lengths of the crown and make test pieces marked appropriately, inside left , inside right with the angles you used. You can then hold these to the ceiling to check the fit and then to the saw to set the angles.

Answer 6

Listen to Jared. Anyone who has cut crown molding at a 45 will tell you it isn't even close. Even the carpenter should know that.
45's only work if the trim is flush against the wall, such as base.

Answer 7

The ONLY way this person is going to be able to install crown molding is to get a good book on installing molding and read it. You'll get introduced to a critical aspect of installing any molding properly:coping.

Answer 8

Jared has good insight on this one.
One thing though, cut the pieces a little "long", hold them up in place to check the fit.
If you cut it at what you think is the true length, you may find you're a little short...
There aren't that many corners to cut, so it's not all that time-consuming and may save you some frustration.

Answer 9

Buy a square and check each corner. In theory, it should be a 45 degree angle, but "true" corner are not found regularly depending on the quality of the contractor that built the home, it's age, weather conditions(humidity), foundation settling,etc. Measure twice, cut once. Err on the side of caution and make the angle less, you can always sand it down to fit, but it's tacky to put cut pieces back on later.

Answer 10

you don't actually cut them both on a 45 you need to scribe them with a coping saw. and you need someone to show you how. I'm sure you can find step by step with photos on line somewhere. If your going to cut them both on a 45 like everyone is suggesting you might as well not do it at all. Once you learn, it is easier and looks perfect no matter what your walls are up to.