# Glue coped inside corners of crown moulding?



## tpolk (Nov 7, 2009)

I dont feel the glue is a plus there. What I have done is used an adhesive caulk that also helps fill gaps as its pushed in place, then finess it with a 5 in one knife by following the contour


----------



## Homeflip (Jan 8, 2010)

No need to glue the joints. Just caulk them. Remember you can nail crown just about anywhere since you should be nailing into the top plate.


----------



## Ron6519 (Mar 28, 2007)

There is no need for glue. The cope might be off due to a wrong setting on the miter saw or a lack of experience with the coping saw. On copes like this, I test fit it with a pieces of scrap laying around. To fine tune it, you can wrap the scrap in sandpaper and use it as a form to get a tight joint. With a painted molding there is a margin of error that can be rectified with some caulking.
Ron


----------



## tpolk (Nov 7, 2009)

how did you establish the run.rise of your crown? looks real flat to me


----------



## Willie T (Jan 29, 2009)

I honestly DO hope you are NOT trying to use bevel settings on the saw. Straight 45 degrees on the swing are all you ever need to do. Using the "upside-down & backward" method, you get perfect bevels everytime.

CLICK HERE to see how the upside-down & backward method works.

Assuming you ARE using this easier "U & B" method, you also may find that marking the bevel edge with a pencil before coping will help a great deal in keeping you right on the profile.


----------



## Klawman (Nov 10, 2009)

*1 out of 4 so far*

OK, the one clear thing is that gluing is out.

No. I have the bevel set to zero. Also, all corners were measured and all are 90 degrees. I am cutting upside down and backwards. I am using a 1X6 for a crown stop. I suspect it may be a problem. That or the molding is snaky. I will check the trueness of the 1x's edge in the morning.

I got the rise and run of the moulding from the manufacturer and confirmed it by laying it in a square. It rises on the wall 3-3/4" and runs out on the ceiling 3-11/16". The spring angle is 45. Here are pics of all 4 corners; none of the boards closer than a couple of feet of each corner.

The first is the second corner I did. The one to the right of the first corner, which is pictured above. I like it.

Next is corner 3 followed by corner 4, each being at one end of board #4. Each has a 1/8" gap between the board it is coped (board 3) and the one coped into the other end of 4 (board 1).

I think other booboos in corners 3 and 4 are repairable. (The point on the coped end of board 4 that fit into the little moritse cut in the end of board 3 broke off. I think I can fashion a repair. As for corner 4, that little brown area at the edge of the coped end of board 1 is where paint flaked off. I think a littel putty and paint will clean it up.)

My guess is I am missing a high point on the back of the coped ends of boards 1 and 4. Less so but perhaps the same area on the cope of board 2. I think I may have to take board 4 down to relieve the back of the cope of 4 and 1, but don't think that the first corner is so bad to warrant pulling it apart.

Anyway, I think I am starting to get it. I figured out too late that perhaps I should be cutting my boards 1/32 shorter. They fit super snug, with the exception of corner 2, the one that came out pretty good. It fit snug, but not tight.

I really appreciate all the advice. This is just my starter/test room. I have much more to do once I get some kind of technique down.


----------



## Klawman (Nov 10, 2009)

tpolk said:


> how did you establish the run.rise of your crown? looks real flat to me


Here is the manufacturer's picture of the moulding I used. It is impossible to read, but it runs out 3-11/6 on the ceiling and has a 3-3/4" rise.


----------



## Klawman (Nov 10, 2009)

*Crown stop isn't perfectly true*

Laid a straight edge against the board clamped to my table to use as a crown stop. There is a high spot in it, perhaps 1/32. This makes it impossible to get the edge of the top of th crown flush against the board. One end or the other can be as much as 1/16" nearer or futther from the fence than the opposite end of the stop. I will remedy that with a piece of masonite checked for trueness and am mad at myself for not checking the edge of the board bought just for use as a stop. Meanwhile, I want to get this room done.

Is that slight rocking enough to be causing the problems I have? If so, can I still save the boards (without pulling them down, shortening them, then lengthenin them with a splice, and cutting a new cope)?

I am going to run a test on some scrap. First I am going to make an inside corner cut with the same stop in place. Then I am going to remove it and cut a piece without a stop or with a pirece of MDF if I have an absolutely true piece in the garage. Than I will compare the two.

Here is a pic of the setup. The pencil is in the area of the high spot along the edge of the stop board. The close up shows how far the straight edge can rock away from the stop if the end of the crown against the left end of the stop board is snug.


----------



## tpolk (Nov 7, 2009)

before we had these slick compounds the old style of cutting worked great with fence tall enough. klaw what i do is take a 2-3' piece coped on both ends and check fit for final cut. You can roll your crown up or down to adjust length of face cut to fit variation in piece already set. i also dont nail piece on wall closer than 12" as this allows me to press the next piece in and by tapping up or down on naile piece you can adjust the angle slightly and thus the fit. hope this makes sense


----------



## Klawman (Nov 10, 2009)

Gave it a try (rolling up the wall) and it solved that issue pretty well (closing the 1/8" gap at the top of the corner. Still, given there were so many little mistakes and I try to take pride in whatever I do, I pulled it all down. Will get new boards and probably trash these, but may do my daughter's room with them as they can be cut down to fit. When messing with the corners, I also discovered where I wasn't cleaning out enough on the back of the cope. Cleaned it pretty well on the wall with sandpaper. What took days to do wrong, I believe I can now knock out without much trouble in a day. Especially as I am getting faster and better at coping with a combo of my cheap skill saw, dremel, sandpaper and file. Should get much better cuts now that I have a smooth and flat stop (which I could have made out of scrap mdf I had on hand). I just didn't want to fill in and sand all the holes from all the times the boards were pulled down. Plus too many points were knocked off of the copings. I llike the look of the points recessed into the mini miters. Thanks again TPOLK


----------



## Augie Dog (Oct 22, 2009)

In addition to rolling the crown a little in the corners, you can sneak a shim or two at the ceiling or wall to tighten a joint if absolutely necessary.

A 1/16" or so can easily be caulked to cover the small gap left by the shim.

Remember that it always looks worse from the staging than the floor. If it looks good from the floor it is good.


----------



## Klawman (Nov 10, 2009)

Thanks, Augie Dog. BTW, I used to live off Sonoma Highway a few miles beyond Santa Rosa. Beforemoving there, lived on Montgomery for a bit. I liked Santa Rosa.


----------



## Klawman (Nov 10, 2009)

The gap between the ceiling and the top of the joint formed by boards 4 and 1, pictured below, was caused by a bad mud job in that corner of the ceiling.


----------



## tpolk (Nov 7, 2009)

if you are using the rail style of cutting you can also roll the piece on the saw rail as this will slightly change your cope, just need to remember which cut you are trying to shorten or lengthen. thats also why i use a gauge piece


----------



## Augie Dog (Oct 22, 2009)

Klawman said:


> Thanks, Augie Dog. BTW, I used to live off Sonoma Highway a few miles beyond Santa Rosa. Beforemoving there, lived on Montgomery for a bit. I liked Santa Rosa.


Both are a couple minutes from my house. I'm near the foothills by Pacific Market. (Grace tract). Although my shop is in Cotati.


----------



## Klawman (Nov 10, 2009)

tpolk said:


> if you are using the rail style of cutting you can also roll the piece on the saw rail as this will slightly change your cope, just need to remember which cut you are trying to shorten or lengthen. thats also why i use a gauge piece


tpolk: Not sure what that is, but if you mean in position against the fence but will experiment with that on some scrap. 

Augie Dog: Pacific Market is either newer than when I was there or I just don't remember. 

I have to decide if I want to refloat that high corner or just cheat the crown. I am leaning towards floating it, but have to take a closer look.


----------



## Augie Dog (Oct 22, 2009)

Klawman said:


> tpolk: Not sure what that is, but if you mean in position against the fence but will experiment with that on some scrap.
> 
> Augie Dog: * Pacific Market is either newer than when I was there or I just don't remember. *
> 
> I have to decide if I want to refloat that high corner or just cheat the crown. I am leaning towards floating it, but have to take a closer look.


Behind the Flamingo Hotel


----------



## Klawman (Nov 10, 2009)

Augie Dog said:


> Behind the Flamingo Hotel


I remember the Flamingo. Had some good times there. No idea what it is like, now. This was 25 years ago. I was a veteran's rep at Santa Rosa JC, where I went part time for a year


----------



## Ron6519 (Mar 28, 2007)

Klawman said:


> The gap between the ceiling and the top of the joint formed by boards 4 and 1, pictured below, was caused by a bad mud job in that corner of the ceiling.


 It's a good idea to take a scrap piece, cut to the ideal corner and see how the cope sets in the corner. Very rarely do they intersect perfectly. Take another scrap and make adjustments in the primary cut. When you're happy with the interface, cut the actual piece.
To make sure you're installing the crown flat against both the wall and ceiling, take a small piece and go around the entire room. Set it correctly and make a pencil mark, top and bottom. Do that 3-4 times per wall. When you're putting the large pieces in, you have a guide as to where it should sit.
Ron


----------



## Klawman (Nov 10, 2009)

Thanks Ron. I sort of did something like that. I made a gauge block the size of the drop down the wall and marked around the room. What I didn't do is run a line along the wall. Had I done so or merely been more observant, I would have seen that the ceiling was high in that one corner. 

Anyway, I ripped those boards off the wall over the weekend. (Not exactly ripped. I can salvage most of the boards to do my daughter's room.) I am going to incorporate your idea of checking each corner with an ideal. That and practice with scrap on adusting cuts. Interestingly, each one of the 4 corners in this room or dead on 90 degrees. I had noticed some minor deviatioins at the wall's intersection with the ceiling, but for some reason never noticed how much that one corner was off.

I picked up the new boards this morning and already have them sanded and painted. Unfortunatley, there isn't much more I can do for the time being, as I understand they should become aclimatized to the house for a couple of days before cutting. (Not sure if this is necessary as I am in So Cal and they are Ultralight MDF.)

Now that I think of it. Of the first atttempt, one corner came out really well. I think I will chop the ends of the two boards that made up that corner and use it as an ideal exemplar for checking corners.

Again, thanks.


----------



## II Weeks (Jan 6, 2009)

why is everyone against using glue? 

anyway, like Ron said, practice pieces or a digital protractor like the one from Bosch. Makes it a little easier.


----------



## Klawman (Nov 10, 2009)

II Weeks said:


> why is everyone against using glue?
> 
> anyway, like Ron said, practice pieces or a digital protractor like the one from Bosch. Makes it a little easier.


How would a digital protractor be of any help? The problem was not with the corner formed by two walls. I measured each corner with a true angle tool to be 90 degrees. The problem was that the ceiling in a corner was higher than it was in any other place along any of the rooms 4 walls.


----------



## Ron6519 (Mar 28, 2007)

Klawman said:


> How would a digital protractor be of any help? The problem was not with the corner formed by two walls. I measured each corner with a true angle tool to be 90 degrees. The problem was that the ceiling in a corner was higher than it was in any other place along any of the rooms 4 walls.


The digital protractor is good for the corners that are not 90 degrees. It's especially helpful with large crown that will be stained. No margin of error for very wide oak crown.
Of course the thing has to work properly, but that's another story.
Ron


----------



## Klawman (Nov 10, 2009)

Thanks all. I think I am starting to get it. Slow but getting faster and achieving better results. I began cutting the wood for the second attempt today, having pulled down the fist four boards. Here is a picture of the first corner completed. It is floating without a nail within 3 feet on either side. (This was one of the boogered up corners. The one good corner during attempt one is floating and matches up just as well to a temporary short board made from scrap. I painted the boards 2 days ago and hope to have very little touch up to do.


----------



## Solarboy (Aug 22, 2013)

This is the kind of advice and suggestions I was looking for. I have an old brick 4-square, and I'm putting up crown molding. It wouldn't be too tricky, except there are not many places to nail...the interior of the outside walls has been insulated with 1 1/2" of foam, then 1/2" drywall. The ceilings upstairs are plaster/lath, and I added an inch of foam and 5/8th drywall. 
On interior walls, I can hit studs...on exterior walls there are no studs or nailers, and on the ceiling the joists are over 2" away.
I think the job will be easier if I install a backer...maybe a 1" ripped narrow enough to fit into the corner and glued in place. Then, use glue on the crown, and use the 1" nailer to hold it in place till the glue sets. 
The last time I did crown, good construction adhesives were not common. Tells ya about how long ago that was, eh?


----------



## Klawman (Nov 10, 2009)

I don't know what the weight of the crown will do to the drywall or if the paper will tend to shear from the drywall. Also, if the drywall is painted any adhesion is actually between the paint and the backer? Have you considered fixing the backer to the wall with long masonry bolts shot through the backer board, the drywall, the foam, and into the brick? Just an amateur's rambling thoughts.


----------



## Solarboy (Aug 22, 2013)

Yeah...the crown is fingerjointed poplar, so it's fairly light. I think I should be able to glue and nail a backer strip, just cut small enough to fit completely behind the crown with some clearance between the two. I should be able to anchor that through the drywall, foam, plaster/lath and into a joist. Once that is set, I should be able to use it to always have a spot to nail. I'm not too concerned about it pulling off the paper, especially if I can tack it to keep the weight off until the glue sets, and if I glue it continuously at the top and bottom of the crown.


----------

