# Crown Molding Corner Gaps - How to Fix?



## biddlecom (May 23, 2017)

Hello Everyone,

I put some crown molding up and did a very bad job.  I have some major gaps in a couple of the corners.  What would be the best way to fill this in and make it look half way decent?  Is there some kind of moldable putty or something like that?  Also is there a good way to fill in the nail holes?  I put caulking in them but there is still a divot.  Any suggestions to get them a bit more flat?

Thank you foe the help!

I just want to know how to fill it in.  Im not going to tear it down and redo it.


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## aNYCdb (May 23, 2017)

I would cut back the moldings and insert corner blocks. I think you will have a hard time filling gaps that big with any kind of mud/putty/caulk.

Example:
https://www.lowes.com/pd/EverTrue-4...d-Inside-Corner-Crown-Moulding-Block/3383426?


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## Sparky617 (May 23, 2017)

Crown can be a bear to cut correctly.  You have to hold it in the saw at exactly the same position as it will go on the wall, only upside down while making the cut.  It helps when you are cutting it to put a stop block to keep all the cuts consistent.  A compound miter can do it with the crown laying down flat on the bed of the saw, but you have to know the right angles to set.  My saw has a detent for "standard crown" whatever that is.

On the narrower ones you could try ALEX caulking.  Water Putty might work on the bigger ones.  You could try water putty on all of it, or where you have indentations just do another dab of caulking.

A great solution to eliminate most of your compound cuts is to use crown corner blocks on the inside corners.

Water Putty
https://www.lowes.com/pd/Durham-s-16-fl-oz-Light-Yellow-Patching-and-Spackling-Compound/3143341

Corner Blocks
https://www.lowes.com/pd/EverTrue-4-125-in-x-4-125-in-White-Hardwood-Inside-Corner-Crown-Moulding-Block/3383426


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## bud16415 (May 23, 2017)

If you ever do anymore learn how to do a coped corner. 

https://www.thisoldhouse.com/how-to/how-to-put-crown-molding

http://www.finehomebuilding.com/2015/01/07/coping-crown-molding-on-inside-corners


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## Sparky617 (May 23, 2017)

bud16415 said:


> If you ever do anymore learn how to do a coped corner.
> 
> https://www.thisoldhouse.com/how-to/how-to-put-crown-molding
> 
> http://www.finehomebuilding.com/2015/01/07/coping-crown-molding-on-inside-corners



The key is to get the crown oriented correctly in the saw and mounting it to the wall at the same orientation.  If the orientation changes from piece to piece you get the wide gaps he has.  Coping won't help a bad compound miter.


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## nealtw (May 23, 2017)

Stuff tissue paper in the crack for backing and fill it with drywall filler, use the corner of the knife to get the corner shape.
Use a sanding sponge for sanding.
No it is no it perfect.


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## bud16415 (May 23, 2017)

Sparky617 said:


> The key is to get the crown oriented correctly in the saw and mounting it to the wall at the same orientation.  If the orientation changes from piece to piece you get the wide gaps he has.  Coping won't help a bad compound miter.



An inside corner cut on a miter even if perfect when done will open and close with the seasons. When you cope the corner the first piece runs straight into the corner no miter. Then you miter the second piece to get the edge and then back cut the edge with the coping saw. Far less likely to see a gap and the cope will pull up tight even if the two corners are not 90 degrees. 

I agree coping wont fix a compound miter it is to replace the miter. 

In his case the best he can do now to make it look right is add in the corner blocks they have them for outside corners as well in some fancy shapes also. I would hand cut them in place.


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## Sparky617 (May 23, 2017)

Bud,
You still do a compound miter on one of the cuts when coping, at least I do.  Square cut one into the corner then miter the other with an inside corner, and cope to match the profile.


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## nealtw (May 23, 2017)

bud16415 said:


> An inside corner cut on a miter even if perfect when done will open and close with the seasons. When you cope the corner the first piece runs straight into the corner no miter. Then you miter the second piece to get the edge and then back cut the edge with the coping saw. Far less likely to see a gap and the cope will pull up tight even if the two corners are not 90 degrees.
> 
> I agree coping wont fix a compound miter it is to replace the miter.
> 
> In his case the best he can do now to make it look right is add in the corner blocks they have them for outside corners as well in some fancy shapes also. I would hand cut them in place.



Bud: We see the pros coping the base molding all the time but I don't think I have seen one do it with a crown.

Any of us that do this once in a while develop little tricks to get there. 
I would like to hear from the pro that does it every day with his tricks.


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## Sparky617 (May 23, 2017)

I installed a really complicated crown in my daughter's bedroom and I couldn't get it to look right by coping.  The key was making sure you cut everything at the same relative angle on the base and backstop of the miter saw and installed it on the wall at the same place.  A slight change in the angle in the miter saw (not the 45-degree cut) will throw off the cut as shown in his bottom picture.  Been there, done that.


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## nealtw (May 23, 2017)

Sparky617 said:


> I installed a really complicated crown in my daughter's bedroom and I couldn't get it to look right by coping.  The key was making sure you cut everything at the same relative angle on the base and backstop of the miter saw and installed it on the wall at the same place.  A slight change in the angle in the miter saw (not the 45-degree cut) will throw off the cut as shown in his bottom picture.  Been there, done that.



Anybody can do it perfect. It takes skill to fix the screw ups.


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## nealtw (May 23, 2017)

Some of the tricks I have used and cheats for beginners

I have screwed a piece of plywood to the table of the saw, just far enough from the fence to replicate where the crown with be on the ceiling.
Make the plywood wide enough so it does not get cut in half when cutting molding.
Cut the two samples for all the different angles you might need for the room.

Using the samples check each corner for corrections needed, sometimes the angle may be right but will a build up of drywall fill will screw things up. A little sanding o the back that fits to the wall maybe needed.

Measuring   inside corner to inside corner can be tricky. measure from wall to center both ways and add the two.

Cut a couple 2x4s to length to hold the piece up while you check both corners will fit the matching samples before you nail it up.

Yes I make a lot of samples and it can be wasteful and the pros may laugh at me. But the finish is always acceptable.


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## nealtw (May 23, 2017)

bud16415 said:


> An inside corner cut on a miter even if perfect when done will open and close with the seasons. When you cope the corner the first piece runs straight into the corner no miter. Then you miter the second piece to get the edge and then back cut the edge with the coping saw. Far less likely to see a gap and the cope will pull up tight even if the two corners are not 90 degrees.
> 
> I agree coping wont fix a compound miter it is to replace the miter.
> 
> In his case the best he can do now to make it look right is add in the corner blocks they have them for outside corners as well in some fancy shapes also. I would hand cut them in place.



This one is for you:thbup:
[ame]https://www.youtube.com/watch?v=IKVx7-DO69M[/ame]


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## jeffmattero76 (May 23, 2017)

I cant help with what to do with the crown moulding, but, for the nail holes, i now use joint compound to fill them. I use my finger dipped in the compound and dab it in the nail hole, and overfill it so there is a lump of joint compound on the face of the moulding. The next day i use a sanding sponge to lightly sand it and it is perfectly flat. I prefer to use quickset powdered joint compound (45 or 90), but have also used pre-mixed.

The reason you still show divots is that caulk shrinks as it dries. So does joint compound and that is why i overfill. The difference is that you can sand joint compound but not caulk.


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## joecaption (May 24, 2017)

I suck at cutting crown, mainly because of lack of practice so I broke down and bought a couple of simple tools to make it easy for even a first timer, and now can get it right the first time.
http://www.cpooutlets.com/bench-dog...svTmRM3BZ6cePzsVlb2iH5UwadamcP8GOBBoCYJLw_wcB
There's pictures on the back of the jig showing what position to set the angle of the saw for inside and outside corners.
The other tool I use tells you in an instant exactly what the angle is.
https://www.walmart.com/ip/Starrett-Hardened-Plastic-Miter-Saw-ProSite-Protractor-505P-7/15107619


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## Sparky617 (May 24, 2017)

Joe,
Does the Starrett Miter Protractor tell you the compound angle to cut crown with the wood laying flat on a compound miter saw bed?  The description is pretty weak on the Walmart website.


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## bud16415 (May 24, 2017)

nealtw said:


> This one is for you:thbup:




It looks like he copes them the way I do and the way the (This old house) link I posted does them. 

Thanks for the link.


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## bud16415 (May 24, 2017)

joecaption said:


> I suck at cutting crown, mainly because of lack of practice so I broke down and bought a couple of simple tools to make it easy for even a first timer, and now can get it right the first time.
> http://www.cpooutlets.com/bench-dog...svTmRM3BZ6cePzsVlb2iH5UwadamcP8GOBBoCYJLw_wcB
> There's pictures on the back of the jig showing what position to set the angle of the saw for inside and outside corners.
> The other tool I use tells you in an instant exactly what the angle is.
> https://www.walmart.com/ip/Starrett-Hardened-Plastic-Miter-Saw-ProSite-Protractor-505P-7/15107619



Thats a great jig. The way the guy in Neals vid holds them to cut them looks sketchy to me. I have always made a jig like the one you bought to hold them square.


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## bud16415 (May 24, 2017)

Sparky617 said:


> Joe,
> Does the Starrett Miter Protractor tell you the compound angle to cut crown with the wood laying flat on a compound miter saw bed?  The description is pretty weak on the Walmart website.



No reason to cut a compound miter if you stand the crown up in the jig. Just measure the corner take half the angle set your saw and use the jig.


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## Sparky617 (May 24, 2017)

Joe,
I like the jig and may get one for my next crown project.  My miter saw is about 15 years old and Bosch has since changed the design and you can no longer find the crown jigs made to fit it.  The one you linked doesn't attach to the saw and is universal.

I'd love a tool that told you want angles to set to utilize the compound feature.  The directions give you an angle for "standard" crown, whatever the heck that is.  You'd think you could say set the compound at XX degrees for 4" crown, XY degrees for 4.5" crown, YY degrees for 6" crown, etc.  A table would be great.  The jig is nice because you set it and all your cuts are consistent.


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## nealtw (May 24, 2017)

Sparky617 said:


> Joe,
> I like the jig and may get one for my next crown project.  My miter saw is about 15 years old and Bosch has since changed the design and you can no longer find the crown jigs made to fit it.  The one you linked doesn't attach to the saw and is universal.
> 
> I'd love a tool that told you want angles to set to utilize the compound feature.  The directions give you an angle for "standard" crown, whatever the heck that is.  You'd think you could say set the compound at XX degrees for 4" crown, XY degrees for 4.5" crown, YY degrees for 6" crown, etc.  A table would be great.  The jig is nice because you set it and all your cuts are consistent.



The height of the crown doesn't change the angle.
The angle of the back is what might change.
THe easy way to find that angle is have a piece of 3" with the same back angle cut that standing up and then lay it down and set the saw to match that.
Somewhere I have a book of angles that came with the radial arm saw.
Finding something like 31.6 degrees never really helped.


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## nealtw (May 24, 2017)

bud16415 said:


> No reason to cut a compound miter if you stand the crown up in the jig. Just measure the corner take half the angle set your saw and use the jig.



Until you get into 8" crown.


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## nealtw (May 24, 2017)

bud16415 said:


> That&#8217;s a great jig. The way the guy in Neal&#8217;s vid holds them to cut them looks sketchy to me. I have always made a jig like the one you bought to hold them square.



cutting it backwards like that would be easy with the angle cut to fit the back sitting against the table. I may try that.


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## nealtw (May 24, 2017)

[ame]https://www.youtube.com/watch?v=JWm7MuHVebM[/ame]


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## bud16415 (May 24, 2017)

nealtw said:


> Until you get into 8" crown.



Band saw with jig and fence.


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## nealtw (May 24, 2017)

bud16415 said:


> Band saw with jig and fence.



The fasted guy I ever saw do a huge crown had a flat jig and he used a skill saw.:trophy:


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## bud16415 (May 24, 2017)

nealtw said:


> The fasted guy I ever saw do a huge crown had a flat jig and he used a skill saw.:trophy:



That foam stuff you could use a bread knife. My dad had a huge miter box that guided the saw. I wish I had that setup. I have coped with a saber saw before.


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## nealtw (May 24, 2017)

bud16415 said:


> That foam stuff you could use a bread knife. My dad had a huge miter box that guided the saw. I wish I had that setup. I have coped with a saber saw before.



You can still find these new.


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## Mastercarpenty (Jun 16, 2017)

I'm late to the party as usual.

@ the OP, if only the bottom is loose you can fix that by shimming the offending part into tightness, then caulking the wall line as needed. Doesn't look as bad as you'd think. Generally if the top is open, you can use a block on both pieces in the corner and tap both upward together which will close the joint. 

@sparky617 there is a chart from Delta which gives you the saw angles based on the measured angle of the actual corner. Works for 45/45 or 38/52 crown. It only goes in one degree increments but you can 'guess' halfway to the next full degree, With my digital protractor and this chart I can flat cut any crown perfectly anywhere anytime. Once you get used to flat-cutting you'll learn where to 'fudge' the cut slightly to open the back just enough to always keep the front tight, yet still have enough mating to get a solid glue bond. You can't do that trick with a 'bedded' cut. 

Coping usually gives the best results but sometimes the wide stuff is bowed and I find that generally works better flat-cut and miter-jointed. Install the the bowed piece first, test fit the other, then wedge out the bow before final joining. If it's bowed out cut the mating piece a little tight to push it in.

My paint-grade filler, whether for gaps or nails, is MH Ready Patch applied with a putty knife to final shape. Almost zero shrinkage unless really thick, dries rapidly, and a bugger to sand so don't leave any excess behind. Don't leave the can open as it dries just as fast there if you do.

With the right tools, knowledge, and perspective on how to solve the problems you sometimes run into, running crown is easy but it might take you years to get all of what you need to handle it that well!

Phil


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## 1acre (Jun 28, 2017)

also late to the party, but it is important to note that if you don't nail up your crown correctly, it will also throw off your miters and coping.  I cope all inside corners.  When outside corners are involved, I make cuts and use miter clips to glue the joint together off the wall.  Once dried, usually by the time I've made the next cuts and laid it out, it helps to lay up the crown almost perfectly.  

Also, in the first picture, it doesn't look like the miter is off, it was just a measuring issue.  Don't measure with a tape, use a folding rule.  No numbers to memorize.  It can also help to take a cut 2 blocks, one the distance on the ceiling and one the distance on the wall and draw a line all the way around the wall to help lay up the crown better.  

Below is a picture of the first time I cut and did crown.  Not perfect, but certainly passable.


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## nealtw (Jun 28, 2017)

1acre said:


> also late to the party, but it is important to note that if you don't nail up your crown correctly, it will also throw off your miters and coping.  I cope all inside corners.  When outside corners are involved, I make cuts and use miter clips to glue the joint together off the wall.  Once dried, usually by the time I've made the next cuts and laid it out, it helps to lay up the crown almost perfectly.
> 
> Also, in the first picture, it doesn't look like the miter is off, it was just a measuring issue.  Don't measure with a tape, use a folding rule.  No numbers to memorize.  It can also help to take a cut 2 blocks, one the distance on the ceiling and one the distance on the wall and draw a line all the way around the wall to help lay up the crown better.
> 
> ...



Nicely done.:thbup:


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