# Butt joining crown molding



## jjrbus (Dec 6, 2009)

I purchased a house that has incomplete crown molding. It is a readably available polyurethane available at HD. I will need a few lengths that are over 8 feet, which is the length they stock.
I have been reading on the net about doing this and it says to use a poly type glue and butt join the molding. I have a bottle of Gorilla glue, not Gorilla wood glue, is this an ok glue for this application??
Butt joint does not seem like an acceptable joint, is it the best way to go??
The expansion on the glue makes a mess, is there a way to protect the finished surface?
I was thinking of useing a biscuit in the joint, good/bad idea? Or using a flat plate, 1/8" plywood or similar to back up the joint, good/bad idea?? The reason I would like to install this as one piece is the ceiling is knocdown and the walls are textured. Horrible stuff to work over.
Any other questions I should be asking?
Happy Holidays JIm


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## Julian the woodnut (Nov 5, 2008)

It was probably incomplete because of the homeowner doing it in the first place didn't know what he was doing. I'm sorry but if it were me I would rip that crap down and replace it with wood. Being a professional I can spot a poly job a mile away.


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## joesdad (Nov 1, 2007)

I'd agree to replace it too, but if you're going to finish it with the same, use something like an overlapping 22.5 degree joint instead of just a square cut butt. This would mean of course tearing down their pieces since they left them square on the free end... A _minimal_ amount of the poly glue would be fine, and you could blue tape your edges if you're worried about the foaming ooze getting on the face. You didn't mention the dimensions of the room, but it might be worth it more to _you_ to just rip it out and start with the real thing instead of spending a lot of time being pissed off trying to get things right only to hate it in the end. If the walls are not too crazy textured, you could just neatly float a nice bead of caulk uder the bottom edge with a damp cloth to fill in the space. 

Good luck, and if you do decide to purchase more of the poly stuff take true measurements of the profile dimensions (a scrap piece would be best) with you to compare with what you are about to buy..sometime profiles can be off by an eighth which will really make steam come out of your ears.


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## Texas Sawduster (Apr 27, 2009)

*Start Over*

I advise starting over.
I would take out the poly stuff and start over. The one thing I learned in re-modeling my den, (see my pics I've uploaded here) is try to make any joints so that they face away from any entrance to the room if at all possible. I have a couple of mitered laps that I will have to sand smooth because the room is 19 feet long I was doing this solo. Fortunately the piece that is proud is the top side of the joint so sanding is to match will not be an issue. Still ticks me off that I have to do it this way.
Also, get help if not for anything than an extra pair of hands to hold up the crown.


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## firehawkmph (Apr 26, 2008)

Jim,
When I do crown, I use one of these, as I am by myself normally.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200304238_200304238

They come in handy for other things too.
Mike Hawkins


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## GeorgeC (Jul 30, 2008)

Years ago I used the Poly "crap" when putting wainscotting in my kitchen. That was a big mistake.

As advised above, rip out and replace with wood. Never but joint, it will always show.

George


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## sagem57 (Mar 31, 2009)

i also would take down the poly. anything other than a flawless joint is going to show. use wood, as you can sand out any miss-alingment. cut the joining ends at any angle from 22 to 45. that way any shrinkage will not show. make a triangular block from scrap, and nail it up where the joint will be, this will give you a solid back up block whick will never come apart. this may be overkill, but if your going to do the job, why not make it last 100 years. and it only takes a few minuts extra. if your going to stain it, try to match the grain of your crown stock , the better the match , the less it will show. also when you purchase your stock, check the profile of each piece carfully, not all of the stock in the rack will be cut with the same set of knives, and there will be differences, in production runs. good luck


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## jjrbus (Dec 6, 2009)

With the variety of materials available, I dont understand why one would be considered "crap". It would seem a professional would be open to all options and use the best one in any given circumstance. 
I had wondered about the blue tape to keep glue off of the finished surface, I will have to expiriment with this befor proceeding.
I am looking at your tool recommendation Firehawk and it almost looks like the load bar from my trailer? I had not thought of useing it, but could work in many situations as a third hand.
JIm


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## Jason W (Dec 18, 2008)

jjrbus said:


> With the variety of materials available, I dont understand why one would be considered "crap". *It would seem a professional would be open to all options and use the best one *in any given circumstance.
> 
> JIm


And that is why the Professionals here are trying to tell you to take it down. We know, we used it, we know what it looks like a few months after a professional installs it, not a novice (just sayin') Add: either way looks like crap!

Just because they sell it, doesn't mean it's any good.

JMHO


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## joesdad (Nov 1, 2007)

jjrbus. There was a time I hated the thought of using MDF (medium density fiberboard) for moldings, let alone anything else for that matter. Now I see it and have used it a lot. Even higher end customers have swallowed their pride and realized that in most applications you can not tell the difference once it's painted. Once they see the difference in cost between a 16' section of 7" crown in pine vs. the same in MDF/primed, they quickly accept that the cost difference is greater than the idea of telling all their friends "By the way, that's real wood under all that paint!"...it aint happening. Composite materials have their place. For exteriors I will always recommend Azek or Koma for exterior applications. It's expensive as hell, but A)It will probably outlast the cockroaches even through a nuclear winter B) It looks nice and is very easy to work with.

The material you have if I am correct (which happens sometimes) is a composite with a semi-glossy surface, yet when you cut it, the edges sometimes melt creating a jagged burr once it cools. The material under the shell usually is not the same color as the shell itself. I've used (not by choice) a similar product maybe twice in the last number of years and remember cursing it both times as being "crap". So don't take offense. Those of us who do this stuff for a living or as a supplemental side job quickly learn what materials work most efficiently and produce the nicest appearance once installed and finished ie: painted or stained.


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## GeorgeC (Jul 30, 2008)

joesday, you mention using MDF more now because of cost.

Do you have access to finger joint wood in your area. In this area I have found that finger joint is very competitive with MDF and sometimes even cheaper. It has all of the advantages of solid wood for those moldings that are going to be painted and none of the disadvanages of MDF. The one weakness is that you do not want to hold a long piece by the end.

George


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## joesdad (Nov 1, 2007)

GeorgeC said:


> joesday, you mention using MDF more now because of cost.
> 
> Do you have access to finger joint wood in your area. In this area I have found that finger joint is very competitive with MDF and sometimes even cheaper. It has all of the advantages of solid wood for those moldings that are going to be painted and none of the disadvanages of MDF. The one weakness is that you do not want to hold a long piece by the end.
> 
> George


George, Absolutely. I'll take the f/j trim any day over MDF, and it is readily available at a comparable cost. Our experience has been on occassion that the f/j pine has been very brittle at the joints on some batches. It is apparent that the 16' lengths of f/j is going to obviously be less tolerant when handled compared to clear trim that is much stronger. It just seems that as of late the profiles are getting thinner (less stength) and in some cases more brittle.

Times are different. It used to be I would automatically price a small painted trim job with poplar. No questions asked by the customer in regards to price. Now days IMO they've educated themselves and will aske me which grade of trim do I use.

If we are trimming for a builder (who selects the material), even the 700-1mil. McMansions are mostly MDF.


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## kburton66 (Apr 10, 2010)

Back to the butt joint. I have some long runs of trim. Baseboard and chair rail only higher. I'm using 3/4 x 6 oak (no profile) and I was thinking of pocket joints or bisquits. I'd like them as inconspicuous as possible. Do you think the angle cut joints will be adiquate.


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## joesdad (Nov 1, 2007)

kburton66 said:


> Back to the butt joint. I have some long runs of trim. Baseboard and chair rail only higher. *I'm using 3/4 x 6 oak* (no profile) and I was thinking of pocket joints or bisquits. I'd like them as inconspicuous as possible. *Do you think the angle cut joints will be adiquate.[/*quote]
> 
> Yes they will be fine mechanically, but since you will be joining two ends of something that won't be painted, you _will_ notice the joint because of differing grain patterns and possibly color. I would lay your boards out on the floor and try to find the best matches before cutting and applying them permanently.


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## cabinetman (Jul 5, 2007)

kburton66 said:


> Back to the butt joint. I have some long runs of trim. Baseboard and chair rail only higher. *I'm using 3/4 x 6 oak* (no profile) and I was thinking of pocket joints or bisquits. I'd like them as inconspicuous as possible. *Do you think the angle cut joints will be adiquate.*





joesdad said:


> Yes they will be fine mechanically, but since you will be joining two ends of something that won't be painted, you _will_ notice the joint because of differing grain patterns and possibly color. I would lay your boards out on the floor and try to find the best matches before cutting and applying them permanently.



+1. Depending on the lengths you have, you may not be just trying to match up the ends of the boards. You may want to shift them left and right on each other to find a good match. On straight runs use a scarf joint and glue, and use a backer or have something in the wall to fasten to.


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## Willie T (Feb 1, 2009)

One thing that has not been mentioned (besides throwing the bottle of Gorilla Glue in the trash) is the aesthetic importance of the direction your overlapping piece runs.

Try to determine if there is a predominate view of the joint. Sometimes there isn't. Sometimes the joint is viewed equally from any direction. But if there is an obvious way from which the joint will be viewed, that is the way the overlap should lie, running with the point facing away from the primary view.

This, alone, will go a long way in helping visually hide the joint. The concept is the same in any 'overlapping' construction, including house siding and fascia, especially aluminium or vinyl.


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## Shamus (Aug 22, 2008)

cabinetman said:


> +1. Depending on the lengths you have, you may not be just trying to match up the ends of the boards. You may want to shift them left and right on each other to find a good match. On straight runs use a scarf joint and glue, and use a backer or have something in the wall to fasten to.


+ 1000, this is one area that patience and some thought pay huge dividends in the finished product.


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