Hiding scarf joint in crown molding??

[steve-u]

I put up some 4 1/2 inch wood crown molding in a room in the house and had to a couple of scarf joints. The cuts were real nice and matched up almost perfectly but after sanding smooth, filling with Elmers wood filler [came in a tube and I believe natural color], sanding again, priming, and two coats of white paint the joint shows through like a pencil mark! What am I doing wrong? Should I be using white colored wood filler or use something else or is this to be expected? I also tried putting some whit caulk over it and that did not help.

One other scarf joint looks worse but thankfully curtains are covering it. I could not figure what I did wrong and then after checking scraps of crown molding I found that they did not exactly match as far as size! Close but no cigar when it comes to cutting a scarf joint. No wonder they try to sell you those corner and mid blocks! Thanks for any help.

Steve

[dlminehart]

Steve, it looks like you did a scarf joint that angled from left to right rather than from front to back. While I've not done crown molding, when I do base molding scarf joints I just cut the molding at 90 degrees top to bottom but angled from front to back. In other words, almost like butting the two boards against each other, but the ends angled when viewed from the top. This minimizes the length of the visible line. I also "aim" the gap between the angled boards in the direction from which the trim is least likely to be viewed.

[Stormbringer]

The cuts were real nice and matched up almost perfectly but after sanding smooth, filling with Elmers wood filler [came in a tube and I believe natural color], sanding again, priming, and two coats of white paint the joint shows through like a pencil mark! What am I doing wrong?
Steve

Steve,
did you use a backer board at the scarf joint. You know, a piece of scrap about 8 to 10 inches long affixed to one side of the joint (ahead of time) so the adjoining piece has no place to go when butted against the first piece? When nailed and glued together, this prevents shifting. Just out of curiosity, since you painted it, why didn't you use MDF? It looks like you were after a particular profile. I did all my rooms with MDF. It's cheaper and won't swell nearly as much with weather changes. Wood crown will almost always show joints or miters due to swelling.

FYI. David's right. The beveled miter you used is recommended for baseboard, not crown. Makes it very difficult to use a scarf joint backer board. Should just be beveled...or is that mitered? It's how David described it

PS. You mentioned the cut didn't match. How did they not match if you cut the left piece and then the right? The angle of the saw wouldn't have changed. Did your crown stops shift on you? That made me nuts when I did mine.

The scarf in this picture is directly above thecenter of the mirror. I could have easily bought another 7 foot piece but I had enough to make the run with two scraps I had left and besides it was 3 in the morning and the borg was closed. The second picture is a close up and I even have a hard time finding it. If you will be doing additional crown, I strongly suggest MDF. Just my $.02

With your current situation, short of taking it down, I would just play the sanding and fill game until you get it right. Don't use silicone as that won't sand well.

Good luck,
Greg

[JimD]

I too use backer pieces of whatever cheap scrap I have around. I have used 1/4 inch luan plywood and 7/16 waferboard. I hold a piece of crown up to a framing square to see how big a backer I can get away with. I then glue and staple it in place on both pieces. When the glue dries it is plenty solid enough to install. I typically do not wait for the glue to dry and I am just careful with it. Short staples shot through the back in the thick areas will not show on the front.

I also agree with the mdf. For painted crown, it's cheaper and more consistent in profile. I do not like it for base in any location where it can get wet - it swells when wet - but for crown I think it is the way to go.

Jim

[Stormbringer]

I then glue and staple it in place on both pieces. When the glue dries it is plenty solid enough to install.
Jim

Definitely agree...but for shorter pieces that don't butt into inside corners. I did this for the seven foot piece in the picture above, and with outside corners it was very easy to shave a hair off the end when I needed. This would have been impossible on the opposite wall where the run was 19 feet and two inside corners. Not easy weilding a 19 foot piece of crown, which is the lenght of the room, that has to fit exactly on the first shot . Used two 9 1/2 foot pieces for that run with the piece with the backer mounted first.

Oh and BTW. Another huge advanatge of mdf is the stock 16ft lenghts the box stores sell.

Greg

[steve-u]

Thanks for all the great tips fellas.

I miter cut my crown standing upside down against the fence for both the corners and scarf cuts all at 45 degrees. Maybe I should bevel cut the scarf cuts laying on the base of the saw. The inside corners all fit and look great and I used a template for the opposite corner to help position it correclty. I just filled in the corner joint with paintable white latex caulk.

What I meant in that the crown did not match for a scarf cut was that the two pieces of crown I used did not have the same exact dimensions. For now on I will double check that and test to see how the scarf joint looks first by positioning the two pieces cut for the scarf joint on a wall before doing final corner cuts.

What I did was nail up 1x2 furring strip around the ceiling so that I could nail the crown to that and wall studs with my PC 16 GA finish nailer. The corners and scarf joints are nailed very securely. I installed the crown 6 months ago and none of the joins has shown any opening yet. I like the idea of securing the scarf joint before installing. Another thing I tried on some scrap crown is to use my PC biscuit joiner to join two pieces using the small biscuit [not the real tiny one]. With a straight end cut that seems to work well so I may do that on my next install coming up shortly. I cut the pieces for the biscuits, glued in the biscuit, and then used spring clamps to hold the joint. When I sanded and finished that joint it looked pretty invisible.

Funny you fellas mentioned MDF as that is what I just bought and it looks just like the wood stuff I am using now at less than half the cost. I got it on safe at Menard's for $6.79 per 8 foot piece.

Steve

[steve-u]

By the way Greg your crown molding install looks great! My wife loves it in her den where I installed it even though I am a bit less than happy but it seems the installer always remembers the flaws!

When you guys suggest pre joining the pieces with glue and backerboard are you using a scarf joint or a butt joint? What to you do to the joint to make it blend in? Any particular filler and glue. I generally use Elmers Carpenter glue.

Steve

[Stormbringer]

By the way Greg your crown molding install looks great! My wife loves it in her den where I installed it even though I am a bit less than happy but it seems the installer always remembers the flaws!

When you guys suggest pre joining the pieces with glue and backerboard are you using a scarf joint or a butt joint? What to you do to the joint to make it blend in? Any particular filler and glue. I generally use Elmers Carpenter glue.

Steve

Thanks for the compliment. It was the first time I did crown and I'm glad I was so particular. Granted most people don't really know how much work goes into it nor do they care about "inside miters" or a "mitered return" but those few in the know are really impressed so that makes it all worth it. I wound up with a lot of scraps

I used a mitered butt joint (does that make it a scarf?) like dave had described with Titebond I (http://www.titebond.com/IntroPageTB.....asp?prodcat=1) and clamped it overnight. From what I've read, the way you did it is more for wood crown for whatever reason. MDF requires a tad more glue than wood and "they" even recommend letting a thin film of glue dry on the MDF before your final coat and assembly.

I too use dsome 1X2 backer on a few walls. Made having to find that stud a non issue and will probably do the entire room with it next time. I'll say it was not easy doing the whole room solo (especially the 19ft run) but with a few 2X4X8 acting as a third hand wedging the crown tight, we made it.

If you have a lot of crown on the project list may I suggest this http://www.easycoper.com/ watch the demo video. I bought a set from Rockler on sale for $28 and man do they make coping much easier. I hated trying to cope corners (no patience) and wound up adjsting my miter saw's angle ever so slightly numerous times over (my celing and walls are from from perfect so simple 45's were out) to do corners instead.

Here's a before and after shot. The two returns, although a b*tch, really came out sharp. There's quite a bit of silicone on them pups

Take care,
Greg

[steve-u]

Wow you did that yourself? At least I recruit the wife or son or both when needed.

I am trying not to cope with the profile crown I am using and cutting the crown upside down in the miter saw against the fence worked well for the first room I did. My corners seem to all be between 89 - 92 degrees from what I can tell.

How did you accurately measure your wall for a single long piece and how much extra did you add to your measurement?? I generally need to trim twice after initial cut as I am paranoid about cutting too short. However if I prejoin pieces I won't be able to run up and down the stairs to the saw but I could put it outside or in the garage which would not be too bad. I learned a lot from doing the first room so I think it will be easier from here on out but I want to make sure I don't have any obvious joints anymore so I am going to go with the reinforced butt joint next time

Steve