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-   -   Any good Copers (crown molding) (https://www.woodworkingtalk.com/f2/any-good-copers-crown-molding-209269/)

Microscopes 12-18-2018 06:40 PM

5 Attachment(s)
Corner is 90.5 degrees. Cut the miter at 45. Coped the cut. And now there is a massive gap.

Any ideas why? Photo attached.

EDIT: Solution added below.

shoot summ 12-18-2018 07:13 PM

How are you actually cutting the molding?

Flat, or at an angle?

Either way you need to go larger on the angle to get more material at the base.

This is why I always cut test pieces first....

FrankC 12-18-2018 07:18 PM

This video explains it, you cut the piece sitting against the miter saw fence upside down, then cope it:


Microscopes 12-18-2018 07:36 PM

3 Attachment(s)
Quote:

Originally Posted by FrankC (Post 2025749)
This video explains it, you cut the piece sitting against the miter saw fence upside down, then cope it:


Yes, this is exactly how I did it. I actually watched this video too!

Brian T 12-18-2018 07:38 PM

I have not installed more than 200' of crown molding through a LR, DR and down all the halls.
The bevels are not 45 and 90 so the cuts are not 45 and 90. You need to know the bevel angles.
The wood has to be swung out on the saw bed against the fence as if it's up on the wall.
Upside down and backwards are the easiest to cut.


You should make an inside corner and an outside corner to get the saw set up correctly.
I know, that's a waste of 4 or 5 feet of molding = well wasted.


When you get the pieces cut to fit correctly, paint the fresh cut wood ends with a black felt marker.
This creates an optical illusion that any gap/mistake is smaller that it really is!!!!

shoot summ 12-18-2018 08:10 PM

Quote:

Originally Posted by Microscopes (Post 2025751)
Yes, this is exactly how I did it. I actually watched this video too!

You need to swing the saw head beyond 45, you will have to dial in the exact angle.

FrankC 12-18-2018 08:18 PM

Have matched the bottom of the molding on the wall to the same distance on the saw?

Microscopes 12-18-2018 09:09 PM

5 Attachment(s)
UPDATE on this.

Thanks for all the helpful replies. What I ended up doing was cutting and coping a small piece for every angle - 45, 46, 47, 48, and 49.

Finally at 49 it got pretty tight. Photo attached. Maybe 50 will be perfect?

But why is my angle finger showing this corner as 90.5 degrees and it needs a 50 degree inside cope to be tight?

Strange...

Microscopes 12-18-2018 09:11 PM

Quote:

Originally Posted by Brian T (Post 2025753)
When you get the pieces cut to fit correctly, paint the fresh cut wood ends with a black felt marker.
This creates an optical illusion that any gap/mistake is smaller that it really is!!!!

Interesting tip!
Thank you!

J.C. 12-18-2018 09:56 PM

Do you have both of them set at the same spring angle? Looks like the piece fastened to the wall might be angled too much.

shoot summ 12-18-2018 10:57 PM

Quote:

Originally Posted by Microscopes (Post 2025769)
UPDATE on this.

Thanks for all the helpful replies. What I ended up doing was cutting and coping a small piece for every angle - 45, 46, 47, 48, and 49.

Finally at 49 it got pretty tight. Photo attached. Maybe 50 will be perfect?

But why is my angle finger showing this corner as 90.5 degrees and it needs a 50 degree inside cope to be tight?

Strange...

That 50 degrees has nothing to do with the corner angle, it relates to the angle(tilt) of the crown it is coped to.

woodnthings 12-18-2018 11:08 PM

That's what I see also....
 
Quote:

Originally Posted by J.C. (Post 2025775)
Do you have both of them set at the same spring angle? Looks like the piece fastened to the wall might be angled too much.

You needed a great angle because the pieces aren't laying against the wall at the same angle. The one on the right is more vertical. :nerd2:

Brian T 12-19-2018 12:09 AM

You are installing crown molding in a house.
There's no law which says that walls are straight and corners are square.
Count yourself fortunate if you ever find such a corner.


You "wing it". You get angles that work, that look good when they go up.
You're most welcome to the black felt marker trick. Try it.



My partner and I are still speaking to eachother after the crown molding episode.
Will be 21 years for us at New Year's Eve. The fekking crown molding is still up there!

BigJim 12-19-2018 01:29 AM

In that top picture, you need to roll your molding. If you were to take a block and place the block at the top of the left hand piece against the ceiling, and tap the block, the molding would come on down the wall and fall right into place. It looks like the mold was not rolled into place right, providing the cut is right. One degree off on a 90 degree corner will not make that much difference, unless you didn't bed the trim on your miter saw when you cut it. But if you did bed the trim and made the cut right, then just roll the trim like I said above.

TimPa 12-19-2018 07:17 AM

I agree with bill and jim. 0.5 degrees off is not what is shown in the pictures - coping actually would not even have cared much at 0.5 degrees off. what is off is how the crown is sitting against the wall. you can see the coped piece is lower on the wall than the installed piece.


with the 2 small flats you have to play with it is difficult to get it right.

try this with a short piece. place the small flat against the wall about 2-3" below the ceiling, rock it back and forth to get the feel of the small flat on the wall. then slide it up the wall until it just touches - that is where it gets nailed. practice it a few times.


I do not nail the last 3' or so of the crown, until I get the next (adjacent) piece in. then, if I have to roll one of the pieces up or down to sit tight, you can do it.

shoot summ 12-19-2018 08:31 AM

This is why I don't like to lay my crown on an angle at the saw, I tilt the head to cut the bevel, too much messing around to make a 16' stick lay at an angle for me.

As others have indicated the spring angle is crucial too, you aren't going to clear up that gap by fixing yours, but it will bet better.

FrankC 12-19-2018 10:48 AM

How I was shown:

Mark the spring angle on your saw with molding upside down, measure the distance from fence to mark and cut a block of wood that length. Use that block to mark bottom of trim on the walls as well as position of studs all the way around the room. You can use masking tape for this, position of ends of lengths of trim are critical, rest of span not so important as long as it is close, adjust by tapping trim with a hammer and block of wood.

Cut the trim upside down at an angle with the bottom edge of the trim on the mark.

Be aware that molding may fit corner at 45 degrees or multiples such as 38 and 52 degrees that add up to 90.

gj13us 12-19-2018 02:00 PM

I'm all about using hand tools as often as possible. But.

I don't have any problems making nice corners with my SCMS. No coping needed.
As an aside-----a few years ago my son was in Cub Scouts with a boy whose father is a contractor. During an activity (building birdhouses, I think) we looked at different types of tools. The contractor didn't know what a coping saw was. How's that happen? :icon_rolleyes:

FrankC 12-19-2018 02:37 PM

Quote:

Originally Posted by gj13us (Post 2025943)
I'm all about using hand tools as often as possible. But.

I don't have any problems making nice corners with my SCMS. No coping needed.
As an aside-----a few years ago my son was in Cub Scouts with a boy whose father is a contractor. During an activity (building birdhouses, I think) we looked at different types of tools. The contractor didn't know what a coping saw was. How's that happen? :icon_rolleyes:

Coping is for when things in the house move so you don't have visible gaps in your joints, not because someone can't cut miters that fit.

If a coping saw could cross cut a 2X12 I guess a contractor might have a reason to use one.:vs_laugh:

Terry Q 12-19-2018 04:13 PM

My miter saw came with a table to make the miter cuts. First step to making coping cuts.

https://uploads.tapatalk-cdn.com/201...9beea5d16c.jpg


In woodworking there is always more then one way to accomplish something.

J.C. 08-07-2019 10:12 PM

I just saw this video today and it reminded me of this thread. So I'll add it for others that find this thread and are new to coping. Understanding The Cope Joint It's a pretty good video but he gets a little carried away with you always cut at 45 to get your cope line. That's not always true.

Terry Q 08-08-2019 12:41 AM

Quote:

Originally Posted by J.C. (Post 2065589)
I just saw this video today and it reminded me of this thread. So I'll add it for others that find this thread and are new to coping. Understanding The Cope Joint It's a pretty good video but he gets a little carried away with you always cut at 45 to get your cope line. That's not always true.



All you are looking for is a line to follow when you cope. The exact angle is not important so long as 45 degrees is close. You are back cutting it anyway and leaving a sharp edge behind. Just the sharp edge has to follow the contour of the mating piece. Its hard to do without a little bit of filing or sanding to get the perfect fit and the hand fitting of the piece will compensate for any angle error.


In woodworking there is always more then one way to accomplish something.

J.C. 08-08-2019 07:03 AM

Coped trim is fairly forgiving for non square corners but a 45 cut only works for 90 corners.

woodnthings 08-08-2019 09:26 AM

Coped VS mitered ...
 
Quote:

Originally Posted by J.C. (Post 2065599)
Coped trim is fairly forgiving for non square corners but a 45 cut only works for 90 corners.


https://youtu.be/Wh7qSR5lWNc?t=417

You have confused the issue by adding the 45 degree miter. The 45 degree cut was mentioned in the video, but not as a miter. It's the starting cut for the cope because it maintains the proper relationship on the ceiling and the wall.... A * plus B* equals C* from Phythagorean theorem. The video does not advocate using 45 degree mitered corners. :vs_cool:

Tool Agnostic 08-08-2019 10:08 AM

We still struggle at it. I hate to admit this, but caulking hides a multitude of sins.

DrRobert 08-08-2019 11:29 AM

Its got to do with the angle you cut it. BTW those tables as shown above are not for coping cuts.

I just miter both sides. Measure the total angle/2 and cut the crown upside and oriented like it will be on wall, down making a single miter cut.


Gluing the miter together before nailing makes a big difference.

Fine Homebuilding IIRC they have a good article about coping crown. Finish Carpentry and Insider Carpentry channel on YouTube have some good stuff.

J.C. 08-08-2019 07:17 PM

What I'm saying is if you watch the video for the first time and have never coped anything before I think some may think no matter what your corner angle is, you cut your trim at 45 to get your cope line and that is always the proper angle to get your cope line. How about if you wanted to cope trim for an octagon room? Your cope is not even going to be close. To get your cope line, you'll need to cut the trim at 22.5.

woodnthings 08-08-2019 09:12 PM

Yes, for sure....
 
The video only deals with 90 degree corners within several degrees more or less, so yes, you are correct. :vs_cool:

NoThankyou 08-08-2019 11:54 PM

I put up crown molding in this house.

The house was constructed in 1962.
Financial consultants took the architects plans and re-did them.
Where I put the crown molding up, not a single wall was perpendicular nor corner 90.
There were inside and outside corners.
I had never done any sort of crown molding woodworking or construction previously.

My solution:
I made a sled for my SCMS. It held the specific crown molding just like you would be looking at it. I have no idea what upside down and backward really means. If you don't have a SCMS, get one. (Mine is an old DeWalt 703) A fine tooth blade helps but not necessary. (Irwin something or other)

Measure the corners with a good protractor and "Adjustable Bevel". Measure the angle ceiling to wall. There are two different angles between ceiling and wall in the corners.

I cut KD 2x4 at the spring angle and put these pieces up with screws into the cap top of the wall behind the wall board. This underlayment does not have to meet perfectly at the corners. Yes, it is extra work but the post work conversation with a neighbor went like this: "Wow that really looks great. Would you help me do it in my house?" "No" "I'll pay you." "No".

The angle that is going to kill you is ceiling to wall. At most it will be a degree and a half off but if you don't account for it, you'll be off by a mile.

Do all the corners first using pieces about 18 inches long. Cut these pieces flat at 45. It is always best for the non corner pointy edge of these pieces to be against the wall. Hold each piece up and you can see which way the corner cut needs to be trimmed. On these 18 inch pieces you can trim a lot to make them perfect. They may only be 16 inches when you're done but the corners will be perfect.

With all the corners done, filling in the space between is simple. Cut these fill in pieces a skosh long. That way you are able to force them into a nice fit. Use something like TiteBond III on the joints. Try not to put nails through the joint area but rather close. My crown molding has been up for over 12 years and looks great.

Editorial comments
IMHO the walls looked just fine without crown molding. However SWMBO said the walls needed crown molding.
I installed pre primed MDF crown molding that I bought at Home Depot. If you are installing natural wood and expect to stain / varnish, you will need a lot more care.
I told SWMBO that I would install but not paint.
Do not worry about filling gaps and nail holes as the painters will take care of that.

NoThankyou 08-09-2019 12:04 AM

I forgot

A pneumatic nail gun is a God Send when doing crown molding. One that shoots 18 gauge nails about 2 inches is great. Mine is a Porter Cable and works very well. Remember to do the 5 drops of air tool oil before connecting the air hose.

BigJim 08-09-2019 10:41 AM

In all the years I did trim work, I never cut an inside corner for 90 degree walls to any other degree than a 45 degree. I never had a problem at all with making a very tight joint. Just roll each piece of ceiling mold until it fits, it is just that simple. I always coped one piece and did not nail the square piece closer than 4 or 5 foot to the corner until I had the joint made. Leaving that square piece loose will enable you to roll the molding to fit perfect.

You would not believe all the unsquare, unplumb, wavy walls I have trimmed

TimPa 08-09-2019 12:17 PM

following on Jim... the installation is just as important as the cuts. it is so important to get the first piece flat and tight to the wall (based on the small vertical "flat" on the back of the crown moulding), so that the next mitered piece can (when also flat to the wall) form the perfect miter. if either of the pieces are not flat to the wall, the pic in the original post is the result.

i always leave the last 3 feet or so of the first piece "not nailed" so that it can move a little as the mating piece is installed. once all is tight, i go back and nail them.

gj13us 08-09-2019 02:58 PM

I like the idea of not nailing down the last few feet until you're tightening it all together.


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