# Crown problem - walls and ceiling not square



## albertalbert

Hi there, I am putting in some 3-1/4" standard crown molding. I measured the angle of the ceiling to wall. Barely out of square (probably 89.5 degrees). I looked at the charts that detail all the different angles for my compound miter saw. The angles were so close to the standard 90 angles (that are preset in saw) that I cut my first cut as if the ceiling/wall were a true 90.

So, the one piece of crown is up on the left. After putting up a 2" sample that tested the joint for the right side, I realized I had a problem. Turns out the wall to wall angle is pretty far off. I measure it at 92 degrees. For the life of me, I can't figure out how to make this right.

So, to sum up, the left side of my inside corner is up, and cut with standard 90 miter/bevel. The wall/ceiling angle is just less than 90. Wall to wall angle is 92. 

Any help would be great - thanks! (Oh, it's paint grade for what it's worth).


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## jlord

albertalbert said:


> Hi there, I am putting in some 3-1/4" standard crown molding. I measured the angle of the ceiling to wall. Barely out of square (probably 89.5 degrees). I looked at the charts that detail all the different angles for my compound miter saw. The angles were so close to the standard 90 angles (that are preset in saw) that I cut my first cut as if the ceiling/wall were a true 90.
> 
> So, the one piece of crown is up on the left. After putting up a 2" sample that tested the joint for the right side, I realized I had a problem. Turns out the wall to wall angle is pretty far off. I measure it at 92 degrees. For the life of me, I can't figure out how to make this right.
> 
> So, to sum up, the left side of my inside corner is up, and cut with standard 90 miter/bevel. The wall/ceiling angle is just less than 90. Wall to wall angle is 92.
> 
> Any help would be great - thanks! (Oh, it's paint grade for what it's worth).


I wouldn't be so concerned about the wall to ceiling angle as much as wall to wall. You should be cutting the crown upside down at the angle it would be as if installed, this is will be in the nested position. All you need to cut is the miter. The position will automatically give you the compounding bevel. The bottom of your crown (most detail) will be up on your saw & against the fence. The top of your crown will be sitting on the base of your saw. Think upside down & backwards where the fence is your wall & the base of the saw is your ceiling & the right side cut will actually be the left side joint & the left side cut will be the right side joint when installed.

To cut crown on the flat you would have to use a compound miter cut(set saw with miter & bevel). For a tight miter measure the wall to wall angle & split this between each side of the cut. For a 89 degree corner each side of the miter will be 44.5 degrees to cut your joint for example. Crown comes in 3 different angles unless custom cut 38/52, 45/45, 52/38 degrees. Higher the wall bigger the degrees (first number) to angle the crown down for viewing from floor level. With your crown being 3-1/4" it is probably the 38/52 degree crown. The side with most detail is usually the bottom side of crown & this will sit against wall when installed & sit against the fence when being cut. 

Best to check out some videos to give you an idea. Just Google - Cutting Crown & you will find many videos to watch. Easy once you understand the procedure


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## GeorgeC

When I ran into this problem when installing crown in my house I found that the best solution was trial and error. I would cut the piece on my left (you could use either side, just my preference) to the correct length and normal angle. I would then use a piece of scrap to determine the angle needed to give a good fit. Once that was found I would cut the right hand piece to this angle.

George


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## craftsman jay

Try to cope the moulding. Then just rasp, file it down if needed. 
Get a book on crown with pictures. Google it. They make corner blocks (I don't like them, but some do) if it's too much a pain.


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## Wooden Moose

I agree with craftsman jay. A coped joint is much better. It will make it easier than trying to find the angles. Always start with a full piece of crown on the wall you see when you walk in the room. Just a rule of thumb I was taught by a master carpenter. There is a wealth of knowledge on the Internet. Try reading up on some info about coping. Good luck, hope it works well for you.


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## jlord

You should still cut to the degrees of an outside corner for a tight joint or you might have an open miter.


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## Leo G

Inside corners should be coped. If you have a 92 degree wall set the saw at 1 degree from 45 and cut an inside miter. Then using a coping saw follow the profile of the cut. Using a dremel or a file make the cut real purty. Then it will fit snug to your other crown. On the outside corners you need to cut the angle as close as you can. If it is off a bit you can roll the molding so they both line up nice. Use lots of glue and a few nails.


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## Willie T

Click here for some ideas on doing crown molding


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## MastersHand

albertalbert said:


> Hi there, I am putting in some 3-1/4" standard crown molding. I measured the angle of the ceiling to wall. Barely out of square (probably 89.5 degrees). I looked at the charts that detail all the different angles for my compound miter saw. The angles were so close to the standard 90 angles (that are preset in saw) that I cut my first cut as if the ceiling/wall were a true 90.
> 
> So, the one piece of crown is up on the left. After putting up a 2" sample that tested the joint for the right side, I realized I had a problem. Turns out the wall to wall angle is pretty far off. I measure it at 92 degrees. For the life of me, I can't figure out how to make this right.
> 
> So, to sum up, the left side of my inside corner is up, and cut with standard 90 miter/bevel. The wall/ceiling angle is just less than 90. Wall to wall angle is 92.
> 
> Any help would be great - thanks! (Oh, it's paint grade for what it's worth).


Bosch angle finder if you are not comfortable coping which I agree should be done.This device is amazing. Take your crown and rest it in device which will tell you spring hit enter. Spring is now saved now take it up the ladder and put it in corner of wall this gives You the corner hit enter twice it will give you the miter hit enter again it will give you the bevel set your saw to left at these degree lay crown on flat with bottom edge of crown towards you cut crown. Set saw to right repeat 
Perfect every time


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## wsommariva

I just finished with crown in my family room. I bought a corner piece that you nail up in the corners and then just install the moulding to each side of it. Very easy and I think it looks better with it than with it, IMHO.


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## BWSmith

I really never have been able to uderstand why certain subjects create so much confusion?Not particularly this thread,its been fairly straightfwd............but Crown in general?

Will not bore ya'll with info about installing then....knowing you'll figure it out and do a fine job.

What I will comment on is the wall surface that you're mounting to.Lets assume(dangerous)its drywall.Have you seen how inside crnrs are taped and mudded?You have in effect big flat planes that again,we'll assume flat that have a buildup of mud at several key areas.Corners,inside and out....joints....and for this disc. we can dismiss nailheads.Its this buildup,in some cases ALOT,that skew inside/outside cornrs from square.....this also applys to plaster walls that utilize bluebd and expanded metal crnr "tape".

Won't bore ya'll on how to fix this....just trying to lay some groundwork here.Try to understand HOW a particular crnr got "out of sq" in alot of cases will bring you to a fact based decision WRT trim(same thing happens with base)and its subsequent install.

A nice 6' straight edge is a valuble tool.Pc of 1/4x2x72 aluminum is decent.Heck,I've hung onto old alum. sliding glas door styles.These make great staright edges for setting door jambs....keep the lockset style(has handle hole built in).Just sayin BW


Edit to add,a wall buttjoint can be a real nightmare if its in a direct line of sight and we have chair-rail or worse yet,runnin some high$$ dado section.For the most part drywallers(pro's) do a pretty good job of keeping buttjoints out of sightline.....but sure as we're planning any sort of wood/dyywall interface they bloomin show up like a sore thumb.Be very aware.


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## rrbrown

jlord said:


> I wouldn't be so concerned about the wall to ceiling angle as much as wall to wall. You should be cutting the crown upside down at the angle it would be as if installed, this is will be in the nested position. All you need to cut is the miter. The position will automatically give you the compounding bevel. The bottom of your crown (most detail) will be up on your saw & against the fence. The top of your crown will be sitting on the base of your saw. Think upside down & backwards where the fence is your wall & the base of the saw is your ceiling & the right side cut will actually be the left side joint & the left side cut will be the right side joint when installed.


I agree with above but he left out what your problem is, the corner not at a 90 degree angle. If the world was perfect you would have perfect corners but that hardly ever happens because of the floating and taping process. 

This is the fix

Using a angle finder which it sounds like you have get the angle in this case 92 degrees. Now when making your cuts you split the angle (92) which means you make your cuts at 46 degrees. 

I hope i didn't confuse you.


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## rrbrown

wsommariva said:


> I just finished with crown in my family room. I bought a corner piece that you nail up in the corners and then just install the moulding to each side of it. Very easy and I think it looks better with it than with it, IMHO.


That's cheating.:laughing:

Really I had those also but it was because of look not to make it easier to install crown and in my case base. It was allot easier I have to admit and so was having rosettes on the door trim.


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## jlord

rrbrown said:


> I agree with above but he left out what your problem is, the corner not at a 90 degree angle. If the world was perfect you would have perfect corners but that hardly ever happens because of the floating and taping process.
> 
> This is the fix
> 
> Using a angle finder which it sounds like you have get the angle in this case 92 degrees. Now when making your cuts you split the angle (92) which means you make your cuts at 46 degrees.
> 
> I hope i didn't confuse you.


Hi Richard,
The second half of my post (#2) did address an out of square corner & splitting the angle.


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## MrMac204

Using the "old" bosch miter finder (not the new one that's out now) use the reciprocal angle. Your wall is 92? use 88 deg. the saw setting will be 44 deg.

This is because the miter finder reads "zero" when folded up. If it read zero wide open then it would give you the correct number. I can't remember why this is though. Every corner is two angles, 90 + 90, or on your wall, 92 + 88. The new bosch apparently takes this into account, but I haven't seen one yet to confirm.

Think of it this way: 92 degrees is wider than 90 degrees, so that means that your cuts have to be shallower- hence 44 deg. (44 + 92 =180 deg)

OR 180 - 92 = 88/2 = 44.

so greater than 90 degrees? you know your answer will be less than 45.

Less than 90 degrees? your answer will be greater than 45.

I also use a rediculously huge saw, the milwaukee 12". It's got the digital readout to 1/10th degree, so its very accurate. This is not necessary though, if your saw has a decent scale you can eye-ball it pretty close.

I cut my crown nested, so I only have to worry about the one number, its way easier than trying to get the "tilt" on the saw anywhere close to what is required.

After a while you find short cuts - what ever happens to 90 degrees, I do the opposite. 92? ok that's two greater than 90, so I will use the number 2 less than 90, which is 88. cofusing! try it with some scraps for a bit, it makes sense after a while. It took me a few years to get that through this old noggin  but then I'm left handed.... LOL

Go to the site compoundmiter.com Wayne Drake has a really good book on this subject.

I'm starting a job tomorrow that 4 contractors have refused- its a vaulted ceiling! that throw all the rules out! I went to my book (mentioned above) and that gives me the numbers. Also got a download from the same firm that has the math for doing this.

Oh! and cope! 
Mac.


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## rrbrown

jlord said:


> Hi Richard,
> The second half of my post (#2) did address an out of square corner & splitting the angle.



So you did. I missed that sorry.


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## rrbrown

MrMac204 said:


> Using the "old" bosch miter finder (not the new one that's out now) use the reciprocal angle. Your wall is 92? use 88 deg. the saw setting will be 44 deg.
> 
> This is because the miter finder reads "zero" when folded up. If it read zero wide open then it would give you the correct number. I can't remember why this is though. Every corner is two angles, 90 + 90, or on your wall, 92 + 88. The new bosch apparently takes this into account, but I haven't seen one yet to confirm.
> 
> *Think of it this way: 92 degrees is wider than 90 degrees, so that means that your cuts have to be shallower- hence 44 deg. (44 + 92 =180 deg)
> 
> OR 180 - 92 = 88/2 = 44.* *
> 
> so greater than 90 degrees? you know your answer will be less than 45.* *
> 
> Less than 90 degrees? your answer will be greater than 45.*
> I also use a rediculously huge saw, the milwaukee 12". It's got the digital readout to 1/10th degree, so its very accurate. This is not necessary though, if your saw has a decent scale you can eye-ball it pretty close.
> 
> I cut my crown nested, so I only have to worry about the one number, its way easier than trying to get the "tilt" on the saw anywhere close to what is required.
> 
> After a while you find short cuts - what ever happens to 90 degrees, I do the opposite. 92? ok that's two greater than 90, so I will use the number 2 less than 90, which is 88. cofusing! try it with some scraps for a bit, it makes sense after a while. It took me a few years to get that through this old noggin  but then I'm left handed.... LOL
> 
> Go to the site compoundmiter.com Wayne Drake has a really good book on this subject.
> 
> I'm starting a job tomorrow that 4 contractors have refused- its a vaulted ceiling! that throw all the rules out! I went to my book (mentioned above) and that gives me the numbers. Also got a download from the same firm that has the math for doing this.
> 
> Oh! and cope!
> Mac.


*Huh?* *A corner is what the angle finder says it is and the miters are cut to half of the angle. If your cutting a corner for an angle wall and its a 45 degree angle you cut the miters at 22.5, if the corner is 88 then the miters are cut at 44.*


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## Leo G

No it is not. I know exactly what he is talking about. Just like on a miter box where 90 is called 0. Sometimes you need to work backwards with the way the machines output the degrees.


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## wsommariva

"That's cheating.:laughing:

Really I had those also but it was because of look not to make it easier to install crown and in my case base. It was allot easier I have to admit and so was having rosettes on the door trim." 

Yes I know but if I used the miter method I would have had to increase my medication. I also used prefabed ends that I don't like - to big. I wished I used the smaller cover pieces.


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## sketel

Leo G said:


> Inside corners should be coped. If you have a 92 degree wall set the saw at 1 degree from 45 and cut an inside miter. Then using a coping saw follow the profile of the cut. Using a dremel or a file make the cut real purty. Then it will fit snug to your other crown. On the outside corners you need to cut the angle as close as you can. If it is off a bit you can roll the molding so they both line up nice. Use lots of glue and a few nails.


Yeah, I use a dremel or sanding wheel on a grinder to clean up copes too. Some of the old guys I've worked with are super fast and accurate with a coping saw and hardly need to touch it up at all.


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## sketel

rrbrown said:


> *Huh?* *A corner is what the angle finder says it is and the miters are cut to half of the angle. If your cutting a corner for an angle wall and its a 45 degree angle you cut the miters at 22.5, if the corner is 88 then the miters are cut at 44.*


Yeah, I see your point but he is talking about setting your saw for coping. No, wait that's how you do it for mitered inside corners. Sorry, I've been building doors for a couple years now. I only make 90 and 45 degree cuts. Took me a minute to think back to trim carpentry.


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## MrMac204

Yup you are right. Technically 44 is 1/2 of 88. The problem is in part that the chop saw is set at zero, and the other thing is that we usually cut our piece "face out"! aha!

so measuring from the back side of the piece, it will be 44 deg, so that means from the front side it has to be 46. (44+46=90)

I gotta sit down and draw it out so that I can explain it better! the fault here is mine, I am a poor teacher.

Basically we are adjusting things so that the machinery gives us what we want.


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## Willie T

If you bevel your inside corner cope very aggressively, leaving a fairly long, sharply pointed edge, small mismatches in adjoining angles will be no problem.

This is because if you cut your piece a little long (like an eighth of an inch, or so) the pressure it will exert when forced (pushed with a spring bow in the wood) into place, the sharp edge you just coped will slightly 'crush' and form itself to the already installed piece.


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## rrbrown

Yeah I agree with you there Willie. You can run one piece square to the wall and cut the other one on the miter cope and it will work. Big advantage to coping.


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## wsommariva

This is why I used the prefab corner.


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## woodnthings

*Cope them*

I was on a job where all I had was a saber saw, miter saw, a belt sander and a table saw. I ran the table saw blade up as far as it would go and then used it to cope, by wasting away the material under the bevel. Then that coped length was fit into the straight section stuck fully into the inside corner. The saber saw worked fair, but hard to control without one of those coping shoes. The belt sander nose also removed the ragged portions left from the table saw. I clamped it to a work table. Worked just fine.  bill


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## cabinetman

woodnthings said:


> I was on a job where all I had was a saber saw, miter saw, a belt sander and a table saw. I ran the table saw blade up as far as it would go and then used it to cope, by wasting away the material under the bevel. Then that coped length was fit into the straight section stuck fully into the inside corner. The saber saw worked fair, but hard to control without one of those coping shoes. The belt sander nose also removed the ragged portions left from the table saw. I clamped it to a work table. Worked just fine.  bill



On short pieces it's just as easy to run the TS blade @45 and use a miter gauge to pass the backside straight through the blade. But, with long pieces like 16' its a PITA. Actually, I find a coping saw to be the fastest most accurate way.












 









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## MastersHand

cabinetman said:


> On short pieces it's just as easy to run the TS blade @45 and use a miter gauge to pass the backside straight through the blade. But, with long pieces like 16' its a PITA. Actually, I find a coping saw to be the fastest most accurate way.
> 
> 
> 
> 
> .


I agree with cab man to many guys around that look at the coping saw as the Ebola virus. If the wall is that far out and you can determine the angle. Yes with the Bosch You can cut the inside miter to this degree cope it with the virus and it will fall right into place. Really not hard don't no why this causes so much trepedation. The key is letting the saw do the work. When my dad trained me he taught me to grip the handle with two fingers when you finally get it you can cut and rasp the cut all in one motion . A good exercise he used to make me do is he would cut six lefts and six rights and make me cut all twelve every day for a month. Then he would take them and try them against another piece of crown and tell me how many sat nice without cleaning them. Another thing he showed me was when your coping with the crown set up on an angle is to stand over it look straight down so you could see if any meat is pertruding past the edge meaning the back bevel of the cut. I was lucky to have a master craftsman as a dad to teach me but You all can teach yourself. Practice use your break and part of your lunch instead of using it to smoke cigarettes. Or cope with one in your mouth


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## fixrite

Just a note to add to all of the wonderful tips and techniques. I picked up a pair of crown moulding holders that hold the crown in place while you install, makes it easy for one person to do the install. I picked them up form Lee Valley Tools. Its like a second pair of hands, and I have found them to be invaluable many times.


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## Willie T

Do yourself a BIG favor if you do a lot of crown.
Buy at least a half dozen, or a dozen, of these sharp pointed spring clamps.
Get a set of pliers too, the springs are kind of hard to open by hand.

Lay some 2p-10 glue on the fitted joint, spray the activator, and slip the clamps on. Beautiful corners.

You might want to take a look at Basswood’s grinder coping technique too

http://www.youtube.com/watch?v=EijqMNYBsLg


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## MastersHand

Willie T said:


> Do yourself a BIG favor if you do a lot of crown.
> Buy at least a half dozen, or a dozen, of these sharp pointed spring clamps.
> Get a set of pliers too, the springs are kind of hard to open by hand.
> 
> Lay some 2p-10 glue on the fitted joint, spray the activaror, and slip the clamps on. Beautiful corners.


I have the glue but Where do we get those nifty clamps . Do they slip a lot of my crown is prefinished


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## cabinetman

MastersHand said:


> I have the glue but Where do we get those nifty clamps . Do they slip a lot of my crown is prefinished


A lot of places sell them, like here. They don't slip per se, but they will leave a divot.











 









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## MastersHand

cabinetman said:


> A lot of places sell them, like here. They don't slip per se, but they will leave a divot.
> 
> 
> 
> 
> .


Thanks to bad I saw these right before the holidays I'll Have to let my helper go and get these LOL


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## fixrite

Although those clips are great, I just used mine to hold a pair of paddes up while I gave them a few coats of marine varnish. I was thinking of these from Lee Valley http://www.leevalley.com/en/wood/page.aspx?p=62045&cat=1,43456


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## BigJim

fixrite said:


> Although those clips are great, I just used mine to hold a pair of paddes up while I gave them a few coats of marine varnish. I was thinking of these from Lee Valley http://www.leevalley.com/en/wood/page.aspx?p=62045&cat=1,43456


I always just used a 10d finish nail to hold the end up for me.


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## cabinetman

jiju1943 said:


> I always just used a 10d finish nail to hold the end up for me.



Working alone can be a PITA. I found this adjustable bar from HF. I have 4 of them and they are a life saver. Periodically, they go on sale for $12.99.

Here's a picture of it holding a backer on a concrete wall.




















 









.


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## BigJim

cabinetman said:


> Working alone can be a PITA. I found this adjustable bar from HF. I have 4 of them and they are a life saver. Periodically, they go on sale for $12.99.
> 
> Here's a picture of it holding a backer on a concrete wall.
> 
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Man, that is a bargain there, I haven't seen them before. It would be kinda hard to drive a 10d finish nail in a concrete wall. Thanks buddy, I appreciate that.


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## Willie T

cabinetman said:


> A lot of places sell them, like here. They don't slip per se, but they will leave a divot.


Prefinished won't shrink as much, but with unfinished crown you will be surprised how much some hot water dabbed on with a sponge will reduce the size of the little holes the clamps leave.


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## Willie T

Fast Cap, I think, also makes a similar bar called "Third Hand". Although they are more expensive than the HF brand, each one will hold a lot more weight. I have four of the Third Hands, and use them all the time to install upper cabinets.

Recently I had to adjust a full wall of eight installed cabinets. (they needed to be 9/16" lower to clear a beam feature) The Third Hands helped me get the whole job done in about twenty minutes.

I don't know how I ever got along without them.


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## fixrite

These are the holders for the crown while doing a one man installation. I got mine from Lee Valley. They work great and leave no marks as you simple hang them on a nail behind the crown in the void. :thumbsup:


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