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crown molding fitting problem

40K views 16 replies 13 participants last post by  Willie T 
#1 · (Edited)
Hello all!
I've installed crown molding before but never 4 1/4". I think my walls are off. On the inside corner, I used the 45 degree cut but when I installed it, the corners turn out to have a 1/4" gap at the top (ceiling) only. My miter saw is a simple cut (not a compound miter saw). I've been careful to hold it correcty against the "fence"? but Ithnk my degrees are off.

It's so frustrating as I've tried so many times to correct the angle with no luck.

Sincere thanks to anyone who can help me out.
 
#2 ·
Walls are rarely 90 degrees, so cutting it at 45 degrees without knowing the actual angle will only be a guess.
Use a bevel guage in each corner to get the actual angle. Are you coping the ends of the crown?
 
#3 ·
I do alot of manufactured homes (new) and your pretty lucky if you ever find a sqaure corner. I run into this problem on every house. What I'll try to do is play with my crown on the saw, slide it up and down and keep trying to get a better fit. Some times I take my razor knife and will trim the back side. I will also cheat and cut a 46 or 48, maybe a 43 degree angle. It takes time and I do get aggervated but I will usually get it, it just takes time and be a little creative.
 
#4 ·
As suggested above, no angle will be 90deg, and not wall/ceiling will be absolutely flat. NEVER miter inside corners, always cope. If you don't know how to cope, pick up a book on finish carpentry, lots of useful info. Start your cope at 45deg, then trim as needed with a file or sharp knife. Before you ever start nailing up the molding, place a piece on the wall/ceiling with the flats flat on the wall, mark and measure. Mark that line all the way around the room. This insures the trim is placed correctly and not wandering up/down.

For outside corners, try with a couple of scrap pieces at 45deg, then change the angle of BOTH, as needed for a proper fit.
 
#5 ·
Crown molding fitting problem

Caulk always works great for me, unless your staining the trim. Inside corners are easier and aren't as noticeable. Outside corners take a coulpe of applications of caulk. After filling viod of outside corner find yourself anything from credit card to a putty knife. Apply a bead of caulk being sure not to apply to much at one time. Use the applicator to follow the contour of each side of os corner build up over several layers following contours until corner is perfected.
 
#11 ·
If you are referring to inside corners, I have never tried to miter these and always cope. You can cope with a non compound miter saw. Coping really isn't tough, just takes some practice.

I personally would not caulk a 1/4" gap. I caulk the seams on my crown, base and window/door mouldings, but never anything with that much gap.
 
#14 · (Edited)
I know this is an old post, but one thing bears mentioning.

Any crown is designed and manufactured to fit up against the ceiling and wall at a SPECIFIC angle in an adjusted and settled placement.

This means that at any point along the wall, especially when you come to corners, the bottom of the crown will be exactly a certain measurement down from the ceiling, and the top of the crown will be exactly a certain measurement out from the wall. This precise alignment has to occur for an good corner to be achieved. And they are not always the same measurements, corner to corner.

Even if you have calculated and cut the precise angles for a given corner, if you hold the bottom of the crown too low, there will be a gap at the top. And it you hold (rotate) the pieces of crown too high, the result will be a gap at the bottom.

Logically, if you have been coming across the wall fastening in a long piece that you were holding, say, too low... it's going to be too low in the corner to match the adjoining piece correctly. You cannot get a good corner fit that way.

One way to help lessen that possibility is to cut a couple of pieces of crown about one foot long. So you won't waste expensive wood you can use both ends of these pieces to cut, first of all an outside corner, and then cut the other ends of the pieces to make an inside corner. Mark them so you can tell how they fit outside to outside, and inside to inside. Or you can just do this with four individual pieces. The point is to have two ends you can hold in either hand and shove together to create either an outside corner or an inside corner.... whichever you need to work with at the time.

Do not fasten these pieces together. Do not 'cope' these pieces.

Walk to an inside corner with your piece of a left inside corner in your left hand. Have the opposite inside corner in your right hand. Step up on the ladder.

Reach up and tilt and slide the two pieces together until they join to form a perfect inside corner. It doesn't matter if there is a little, uniform gap the full length of the corner........ when you cope the end butt, that will be taken care of. But the gap must be uniform, not bigger at the top nor bigger at the bottom.... the same (uniform) all the way.

Now, with a very sharp pencil, carefully mark the walls along the full lengths of the tops and bottoms of both pieces of wood.

Do this to all the inside corners. These marks are where the future pieces of real crown are going to have to be mounted, both on the wall and on the ceiling.

You are now ready to turn your attention to the outside corners.

Do the same thing, only this time using the pieces that fit together to make an outside corner.

Get the same good fit.

Mark the walls.

Here comes the change up.

If the trial fit leaves you with gaps in the outside corner pieces, you are going to have to do something about that since you cannot cope outside corners to take up the slack of a slight wall angle mismatch.

You do this by using your eyes and your brain. A little open in the fit? Well, obviously the outside corner there is not a true 90 degrees, but (since the gap is on the front side of the crown) perhaps 91 or 92 degrees. Let's say 92 degrees to keep this simple.

What did you originally cut that corner angle? Yes 45 degrees....... because the hoped-for angle was 90 degrees. 45 is half of the full turn of 90 degrees. You match up two 45 pieces, and they add up to a 90 degree corner. You still with me? Great.

But this corner is 92 degrees. What do you suppose the angle on each corner piece would be to end up with a 92 degree corner? You need two more degrees... half of that amount on each corner piece that will soon be added together to make the complete 92 degree corner up there on the wall.

I'll bet you guessed 46 degrees. And you would be right.

So, after you have gone around to ALL the outside corners and done this fitting/marking thing, you are ready to go back to those few corners that fit poorly and work on figuring out what to do to each of them.

Hopefully, you were wise enough to have already written on the walls of those 'bad' corners approximately what you thought the angle adjustments might be. Smart people do things like this to eliminate double work. (Of course you write this information up high where the crown will eventually cover your markings so you don't have to paint over them later.)

Here is the reason you waited till now to do these odd outside corners. You will now begin re-cutting your outside corner pieces, destroying the original 45 degree corner cuts you first made. This helps you keep from wasting wood by having to somewhere cut more of those original 45 degree pieces... you already used them, and no longer need them at those angles. All your cuts for these weird corners will be something other than 45 degrees.

Now, one corner at a time, you begin re-cutting your trial pieces to the guesses you made for angles. Move your saw from 45 degrees to maybe 45-1/2 degrees, and cut both sides of the corner again. Take off as little material as you can when doing these new cuts... no need to lope off big pieces and waste this expensive wood. Do it carefully, and you can get all this trial and error done by wasting only these two pieces of wood. (or FOUR if you went that way)

Go up on the ladder and check your new fit. Fits? good.

Not yet to your satisfaction? Go back down and reset the saw for another half degree. Re-cut both corners. Check again.

Keep doing this on all corners till they fit right, THEN mark the revised angle for each individual corner on the wall at that corner. THIS is the angle degree setting you will use when cutting THAT particular corner when you cut the real crown.

Some corners were open at the back and not the front? Usually this is not too big a deal to have to mess with, but sometimes it is. In these cases, of course you don't go bigger with the angle settings on the saw, but instead, you go smaller.

Same trial and error cutting and fitting, but your angle settings will read maybe 44-1/2 degrees or even 44 degrees.

You get the idea. Don't get in a hurry. Rushing is going to almost always confuse you. Work slowly, thinking (and feeling confident about your conclusions) your way through each calculation and cut.

I hope this helps some of you understand why seemingly perfectly cut corners just don't want to cooperate at times. They DO have to be aligned, one to the other for each individual corner. This is why the pro crown installers charge so much. It's not a slap and stick game.
 
#16 ·
Below are some small tools that will be helpful to you.

The plastic holders and Spring Clamps are purchased, but the wooden placement stick and wire hangers are homemade.
 

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