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Crown Outer Corner - Help?

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Forum topic by NitroMike posted 07-19-2017 01:53 PM 1076 views 0 times favorited 17 replies Add to Favorites Watch
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NitroMike

2 posts in 428 days


07-19-2017 01:53 PM

Topic tags/keywords: crown crown moulding outside corner miter angle gap

Hi Lumberjocks!

Total beginner here. I spent several hours today on an annoying issue which likely would’ve been a cakewalk for most of you, so seeking some assistance!

I’m using crown to hide some wiring in a basement theater room. It’s my first time doing crown and I did a passable job on coping all the inside corners. I reached the final bit which is the only outside corner in the whole room. I cannot for the life of me get it to work!

The corner measures 91 degrees. I have a compound miter but I’m just doing the standard upside down-reverse cut method for all my cuts, so just miter angles. I tried cutting each piece of the corner at 44.5. No dice. I tried several other angles and re-measured the angle 10x. No matter what cut angles I try, I keep ending up with a triangular gap at the corner.

Any thoughts? Is it my angle? Warped wall? Maybe cut length? I’m going slightly crazy.

See image below – just using scarf joint scrap to figure out the angles before I redo both sides as 1 piece each.


17 replies so far

View builtinbkyn's profile

builtinbkyn

2633 posts in 1056 days


#1 posted 07-19-2017 02:25 PM

Cut and assemble a corner on the ground until you get a good fit. Make each if the sides long – maybe 18 -24 inches. Then scarf joint each side. So basically you’r installing the corner first and then mating each side to the corner.

-- Bill, Yo!......in Brooklyn & Steel City :)

View Loren's profile

Loren

10477 posts in 3764 days


#2 posted 07-19-2017 02:31 PM

Do you understand crown “spring angle”?

While it would make sense to installers
to have 45 degree crown be the most
common, in my experience 38 degree
crown is common. You have to figure out
the spring angle and calculate your cutting
angles from that information.

View firefighterontheside's profile

firefighterontheside

18842 posts in 1973 days


#3 posted 07-19-2017 02:40 PM

Here’s what I would do. Cut one piece at 45° making sure it’s the right length and nail it up. Use a small piece to find the angle that works for the second piece. Once you find that angle, cut your second piece. Since one piece will be a 45 and the other something else, one of your long points will be a little long. Trim it flush after its up. You will be having to fill nail holes and touch up the paint anyway. My dad taught me that it’s the painters that make the carpenters look good, at least with painted trim.

-- Bill M. "People change, walnut doesn't" by Gene.

View ArtMann's profile

ArtMann

1041 posts in 932 days


#4 posted 07-19-2017 06:27 PM

I think Loren will win the prize for the best answer. None of the angles you cut for crown molding are even close to 45 unless you place the molding on the miter saw upside down at the exact angle at which it will be installed. You normally would make a jig to do that because, as Loren said, the spring angle is almost never 45. There are lots of do-it-yourself explanations on Youtube.

View hotbyte's profile

hotbyte

991 posts in 3092 days


#5 posted 07-19-2017 08:51 PM

I’m pretty much “self taught” on trimming but this would be my approach.

As mentioned, be sure you are holding crown upside on saw and installing on wall at the same spring angle. If your ceiling/wall isn’t 90, that can have impact. Cut one side to length with 45 on end and nail only from opposite corner for 1/3 or so of length. Leave corner loose so you can tweak fit. Cut about 18” test piece at opposing 45* and using it, work the pieces on the corner until you have best looking joint. Then, finish nailing the first piece. Cut second piece a little long and test/trim/test until you have nice fit. Start nailing that piece at the mitered corner.

View jbay's profile

jbay

2583 posts in 1015 days


#6 posted 07-19-2017 09:01 PM

It is all about the spring angle.
At this point,
Measure the crown that is already (nailed the shit out of) on the wall. lol it ain’t moving..
Measure from the wall to the face and from the ceiling to the bottom.
When your cutting your crown on the saw you will have to replicate the same measurements on the table and fence so that your cutting everything at the same spring angle.

View pintodeluxe's profile

pintodeluxe

5739 posts in 2929 days


#7 posted 07-20-2017 01:31 AM

Clamp or tape a ledger board on your miter saw for a uniform spring angle. Using the upside down and backwards method as you are, they will be simple 45 degree cuts. However… as others have mentioned you have to set each piece of crown molding at the right angle on your saw as you cut it.

That is where the ledger board comes in. Double sided carpet tape works great to temporarily hold it to your miter saw.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View SuperCubber's profile

SuperCubber

1036 posts in 2400 days


#8 posted 07-20-2017 03:52 AM

Assuming spring angle isn’t the issue… You said the angle measures 91 degrees. You also said you cut the pieces at 44.5 degrees. 44.5+44.5=89. Could that be your issue? Maybe the angle you are looking for is 45.5?

-- Joe | Spartanburg, SC | "To give anything less than your best is to sacrafice the gift." - Steve Prefontaine

View ColonelTravis's profile

ColonelTravis

1876 posts in 2010 days


#9 posted 07-20-2017 04:19 AM

I did crown in our whole house a couple months ago, this thing was worth the $30. Also comes with a cheap angle finder for the spring and wall angles. There are diagram stickers that remind you where to set your saw for L/R inside and L/R outside cuts.

Trust me – I feel your pain. My first room it took me 4 hours to get past my first outside corner. I’m an idiot with a left/right problem, and cutting upside down compounds that idiocy. But if I can do it you can do it. At the end I didn’t need any more test cuts, no major screw-ups. You’ll eventually get the hang of it. But it’s not the most intuitive project to tackle.

View Ripper70's profile

Ripper70

1113 posts in 1025 days


#10 posted 07-20-2017 06:05 AM

Try this link. It may help.

-- "You know, I'm such a great driver, it's incomprehensible that they took my license away." --Vince Ricardo

View Tony Ennis's profile

Tony Ennis

128 posts in 3252 days


#11 posted 07-20-2017 12:09 PM

I’m not as sophisticated as the guys above. Be sure you’re placing the trim into the saw correctly. That is, it must be in the same relative orientation as it will be when installed, though you can put it in upside down. You may have to build a jig to hold the trim in the correct position.

Cut one piece to 45 degrees and nail it up. We’re not changing this piece again. Cut the 2nd piece to 45 degrees and hold it in place for fitting. That is look at it to see if the joint is open or closed.

If you’re way out, put it back on the miter saw and cut a sliver off as appropriate.

Find out where you’d have to remove a little wood from the 2nd piece to improve the fit. With a block plane, trim the place where the 2nd piece contacts the first piece. Repeat until the gap is acceptable.

I have used lipstick in similar situations to serve as a marking dye. That is, put a thin layer on the first piece, butt the 2nd against it, and trim the 2nd where it picks up lipstick. They make something for this, I don’t know what it is called. Inlay fluid, maybe?

-- Tony

View rwe2156's profile

rwe2156

3069 posts in 1597 days


#12 posted 07-20-2017 01:12 PM

If you read his post, he IS cutting it upside down.

Besides that, maybe you should tell him exactly what “spring angle” is. I would sure like to know!

My advise is first check and make sure your ceiling is 90° to the wall. It looks to me like there might be a slope in the ceiling.

My experience is walls are typically less then 90° due to the drywall corner bead so a 45 should work.

You’re just going to have to keep making test cuts till you get it close enough.

Make sure you glue the joint together!

-- Everything is a prototype thats why its one of a kind!!

View hotbyte's profile

hotbyte

991 posts in 3092 days


#13 posted 07-20-2017 01:35 PM

rwe2156,

Spring angle is angle of the crown to the wall. If you place crown on the wall with the bottom flat section tight against the wall, it will slope out at the spring angle. ( example )It is predetermined by the mfr of the molding and, as mentioned, is often 38 degrees. When cutting using the “upside down” method and installing it is important that the crown is set at the appropriate angle. As you note, the wall and ceiling not being 90 degrees can impact that. For example, if the wall/ceiling angle is > 90, you might need to shim the gap between top of crown and ceiling. Our house was built in 1895 so there are some huge variations in wall/wall and wall/ceiling angles! As my friend says, “Caulk and paint will make a carpenter what he ain’t!”

View Snipes's profile

Snipes

184 posts in 2361 days


#14 posted 07-20-2017 02:23 PM

I always keep 2 pieces about a foot long in my pouch, get them to fit perfect first. Then put your full length pieces up keeping your nails back about 4 feet. Then get some glue in your miter, and due to crooked walls and or clg, very often you have to cheat the crown up or down on the wall to get a perfect fit. Last you can slightly round over edge to hide any gap. hope that makes sense…
Also don’t use so many nails, can’t be backer behind all of them. And trying to get a good fit with such small pieces is dangerous and hard to do.

-- if it is to be it is up to me

View NitroMike's profile

NitroMike

2 posts in 428 days


#15 posted 07-22-2017 03:43 AM

Hey All,

Thanks for all the awesome answers! I got around to finishing the job today. As many of you mentioned, it ended up being the spring angles. Both walls leading up to the corner had totally different angles that were anything but 90. I ended up figuring out one side as many of you advised – had to cut it at about a 47 with a much wider set spring. Looked perfect and then I trial and error cut the other piece to fit as close as possible. After some fancy sanding it doesn’t look half bad!

Caulk is setting up now and paint will get slapped on tomorrow! Caulk use was liberal since this has proven once again I’m sure as hell not a carpenter ;) That saying fits me well.

Thanks again all!

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