Question
Any tips on installing/cutting crown molding? Right now it seems to be a huge bottleneck in my installs, especially coping inside corners.
Forum Responses
(Cabinet and Millwork Installation Forum)
Here's one take from a maker/installer's point of view. If you are installing crown into a wall to ceiling situation with bumps, out of squareness, etc., then coping is very useful when coming into an inside corner. My approach when setting crown to my own blocking set on top of the cases (I build frameless) is to cut all miters in the shop and deal with only square cuts at the site. I try and deal with anything possible in the shop because it always seems to get more difficult once you are on site. I like a glued miter joint when I'm dealing with a flat and square background of my own making. Not sure if this addresses your problem areas but thought it worth a try.
I use a crown molding software program to calculate the bevel and miter cuts. So no trial and error in the field. And I put up the long pieces first with straight cuts so the shorter pieces have the cope. I use a tablesaw on an installer's workbench (foldup unit) to hog out most of the material for the cope. I use a sanding block or belt sander to finish. The bigger the crown, the harder it is to do. I tried the coping foot with a jig saw, but it seemed to solve one problem and create another.
Crown over 4" is really difficult, no getting around it. Small bandsaw, jigsaw, coping saw, they all have their drawbacks. Even the best craftsman will work hard to make a good crown install. Charge your customer for it.
The best improvement I had with installing crown was the software. I use a program by "Easy shop series" but I don't see it marketed anymore. There are some other programs. Also find a miter chart and give everyone a copy. Not quite as good as software, but you can get fairly close.
| View a sample of Gary Katz's Crown Installation Video Gary M. Katz |
a) Getting all mouldings supplied with pre-machined cope on both ends or
b) a small template guided machine that will machine the cope on site.
Would either of these ideas be of interest to installers?
From contributor P:
On small jobs I plan out pieces and cope all but the last piece. If crown is long enough to do a room in 4 pieces, I cope 1 end on 3 pieces in the shop and the last one is a cut to fit double cope in the field. Professional installers still need to be good at crown install - it's their job to learn it.
I've never seen or heard about any kind of template or machine to cut a cope. If you know of one, share with the world its existence.
A real good math freeware program will calculate compound miters. You just need to be a little math savvy.
Maybe a good business for someone that has a metal CNC machine. Just fax in a drawing of your crown molding and a week or so later get your template. Kind of like how my custom shaper knives get done.
I don't know if Art Betterly is still around, but I remember seeing him about 20 years ago working with Porter cable on designing odd router applications.
My machine would use a small router bit or rasp blade, working from the same 1:1 plastic template Weinig uses in our grinders (cheap to duplicate, can be readily supplied with moulding). All I have to do now is make it!
What determines if cope should be cut onto LH or RH piece of moulding? How important is that choice? A machine gets more expensive if it must do both.
As far as pre-coped, here is my bit for the small shop/installer. I did a crown job for an enormous library coffered ceiling. The openings were between two and four feet square. Some were trapezoidal, thus adding to the grief. Several hundred cuts. Now the fun part. It had to be pre-finished cherry with conversion varnish. The original shop/installer failed to install the crown and left the state. Home library was occupied. With no cap on price, I pondered it for some time, knowing good measurements and pre-copes were the only hope.
Since my shop work revolves around my SCM T50 shaper, I had a coping profile cutter made. I ran all the crown, then cut the lengths to exact for butt. I then made several fixtures to hold the crown at the required angles, right and left. These were also designed to eliminate tearout. The ends of the fixture were cast out of Bondo to give a perfect fit to the crown. This was the trick for a smooth cut.
In a nutshell, my shaper was turned into a coping machine. It worked great. All pieces were fit, filed if required, identified, brought back and finished. All were then pin nailed upon installation. In the end I had an amazing respect for the installers coping and fitting on site. They earn every penny.
Another thought is a machine that uses a sample of the crown itself as a template. This would make it useful to guys that don't make their own mouldings and wouldn't have templates from their knives (that they don't have). I make mouldings but use a coping saw to cope them!
Another way is to figure what you are going to pay yourself per hour. For me, it's 35 per hour. And I figure about 10 to 12 feet of crown installed per hour. So a square room, 12 x 12 is a half day's work to set up, fasten blocking, install, putty holes and move on to the next room.
If there is high ceiling and you need scaffold, or furniture is in the way, add the costs to the per foot method.
And to speed things up, figure out what the angle of the crown is to the wall, and do some of the cope joints before packing to the job site. The compound angle formula from my spreadsheet will figure the angles in a jiff.
Enter this in your favorite spreadsheet.
compound miter formula - entered in row 15
cell 1 - slope a in degrees
cell 2 - A15*PI()/180
cell 3 - slope b in degrees (note: slopes a and b will be the same when figuring crown molding)
cell 4 - C15*PI()/180
cell 5 - wall angle in degrees
cell 6 - E15*PI()/180
cell 7 - ATAN((COS(B15)*TAN(D15)+SIN(B15)*COS(F15))/SIN(F15))
cell 8 - G15*180/(PI()) miter cut in degrees
cell 9 - ATAN((COS(D15)*TAN(B15)+SIN(D15)*COS(G15)/SIN(G15)))
cell 10- 90-(I15*180/(PI())) bevel cut in degrees
For the record I don't plan to develop my own cope machine until I see the system already developed by Bill Shaw (the trim cope machine is called the Copemaster, Shaw Millwork, CT). I need to be sure that my concept does not conflict with his.
Comment from contributor A:
First get a Bosch DWM 40L electronic miter gauge and use it for all corner measurements as it figures compound cuts/miters on crown based on the spring angle. Only drawback is that spring-angle has to be inputed for each measurement.
For crown under 5" a regular miter saw with 3" tall fence has been modifed by drilling holes through it to allow a strip of wood (2x) ripped to spring angle to be attached to fence at a height that allows for wall surface of crown to rest against fence. Then set
angles by cutting a left and right miter angle, and you're left with exact index where the blade meets crown, enabling incredibly fast and accurate cuts.
For crown larger than 5" we use an old saw-buck with an auxillary wood (3/4" ply) cutting surface (to index kerf). I measure all sides at once, cut and install the shortest side first (cut to exact length) then spring the longer pieces in place (depending on surface - drywall or wood - cut 1/32 to 1/16 longer).
Haven't coped a joint in years.
Carpentry is a controlled series of screw-ups. If floors and ceilings where perfect (and stable) there would be no need for molding. My priority is tight lasting joints. I feel I can achieve that faster with miters. I get the angle right with flat stock, cut the crown from the bottom dimension and tap with a wood block and hammer until airtight. I do cope simple trims like Ogee and quarter round, primarily because it saves the effort of finding the angles (it seems that most inside corners in drywall construction are less than square). Strangely, it does not matter to me whether the teeth of the coping saw face up or down.
Here is another can of worms. When it comes to splices in the field, I butt cut the joints. I can see the heads moving left to right in disapproval. Long lengths of crown molding are sprung into place and under an ever-changing amount of pressure. I have seen even 22.5 degree scarfs walk out of flush after five years. Sometimes simple is better.
After giving a lot of thought to what tool would be able to eliminate the backside of a mitered corner to produce the perfect cope, it dawned on me that a Dremel with the right bit might work. After trying all my bits, I was surprised at how affective a drum sander bit was. Because of its large round drum side, I was able to shape and grind away the material and follow the profile of the crown with a lot of control. In areas where the profile came to a point, the drum sander was also effective by turning the head of the bit sideways and cutting in with the top edge. Excited by the idea, I researched a more sturdy bit and found that Dremel makes a carbine sanding belt which I found online for $6 each. I just finished the job and my coped corners are virtually flawless. The carbide sanding belt with Dremel allowed me to shape away the perfect profile and create great fitting coped corners. Using the dremel tool I have to remove all the "white meat" of the cope by grinding it away, but with the carbide bit, it's pretty fast and the control and finished results of this tool blow away doing it by hand or with the Collins foot.
I learned two more things about working with crown moulding. On outside corners, I have found it best to make the corners on the ground and install a finished corner that is perfect. It's just too tough for me to joint boards on the wall for outside corners and get good results. With MDF especially, a hot glue gun forms tight strong outside corner joints and is the perfect tool instead of trying to nail it together.
Also, when I do crown moulding, I do all horizontal turns of the saw with the crown upside down and leaning against the fence of my compound miter saw. Personally, I built a taller fence for my miter saw so that I can lean crown upside down in the saw and easily hold it at the correct angle leaning against the fence. It really speeds things up. Also, its true that most corners are 90 degrees, but when you get one that isn't that is an outside corner, you can't keep the joint tightly together if you don't adjust your miter to the actual angle of the corner. The most important thing about doing corners other than 90 degrees is to check that your saw is square before trying to cut anything other than 90 or 45 degrees. I adjust the fence and the tilt of the saw to make sure I get 90 degree readings against the saw before starting. I have found that saws out of the box aren't in good enough alignment to ensure tight joints.
Buy a Hitachi 10" with laser and the Hitachi work station. Read the Hitachi manual and learn to cut crown flat. I don't care if it's 5 1/4, 7 1/4, blah, blah. First, cut your long runs square. Use the drop off a piece over 3 feet, preferably as a tell stick. You will need several per job for ins and outs. Cut a perfect (Hitachi makes this easy) inside 45 / 22 1/2 and cope same with outsides, just no cope (duh). On your copes use your great grandfather's coping saw. In the absence of that, buy 3 of those cheap ones - I go through about 10 a year. Never can have enough blades. Hold the coping saw right (the end of the handle should rest inside your palm) - this isn't a rip saw.
Okay, so you can cope now. Take a mini grinder with 60 grit (this takes practice, but it's not too hard) and wham - you're done. Measure wall to wall, not your long runs details to detail. Oh, the tell sticks help you make micro adjustments from true 45/ 22 1/2... I love doing 8 sided trays and double trays - that's money, honey. 16 corners times 20 and you can bake them in 3 hours or less. Who says lawyers have all the fun?
There is no trick to installing crown, once you know the basics. Measure the length of the wall and add 1/16. Always check the angle of the corner with an angle finder. I use the DeWalt 708 CMS for all my jobs and have found it great.
There is no such thing as a perfect corner, especially in tract-homes. 92/88 degree corners are common, and if you know the formula for the compound cut, your job is simple.
- Measure and rip a beveled back rest that will lay against the fence, holding work secure and hopefully safe (in the position it will be mounted). This will vary with width of mould. ALL mould cuts will be made with the top edge down.
- For an inside left-hand corner, the blade is at 45 degrees and swung to the right-hand side.
- The mould is also on the right side, top edge down.
- Left inside corner: Blade left, mould left, top down.
Outside corners:
- Right hand - blade right, mould left, top edge down.
- Left hand - mould right, blade left, top down.
If rooms are longer than material length, add 45 degree miters for overlap joint. Always do left or right ends the same and add paintable caulk/putty to all joints prior to assembly. Wipe excess with damp rag.
There is still some skill in following the contour, but the jigsaw is positioned in such a way that it gives you an undercut or back cut that is always consistent and you never have to take any more off the backside with a grinder, rasp, or whatever method is used. It's simple and easy.
As for crown installations on wall to ceiling applications put the cope where you will not be looking directly at it when you enter the room. Also a right handed carpenter will prefer a left handed cope and vice versa. This is due to the angle of the back cut and how the coping saw is held. I am aware of a coping machine but you would have to install thousands of feet of crown for a machine of that nature to be financially feasible.
A grinder will also do the trick but it is loud and dusty. Large crown might call for the hogging method and a grinder, but for most of us 4 1/4" crown can be done efficiently with a medium toothed coping saw. Make sure to set the saw blade so it cuts on the push stroke. This is a method that will make things quicker and cleaner.
There are a few new tools or should I say aids that make coping much easier. There is even a power coper available if you want to spend the money. Many of the new aids are inexpensive and believe me make your job much easier. One is a guide system called EasyCoper. You can master this set up in about 5 minutes.
I take all of the pieces to the room and hang them. I hang the square end first, then left cope piece, and then the right cope piece next, always leaving the ends of each piece of crown hung and not nailed 3 to 4 feet from the end to allow flexibility when tying in a coped end to it. Lastly I put in the piece of crown that is coped on both ends and nail it off. The time it takes to measure a room, cut the crown, cope the crown and hang the crown is 1 hour. I charged $10.00 per corner inside and outside and $10.00 per splice if the room is over 16 ft. So a square room not over 16 ft. would have 4 corners at $10.00 per corner = $40.00 – that’s $40.00 per hour. This $20.00 per corner + $3 to $4 per foot is high, and taking a half a day to do one room is way too long.
One last thing - try using a coped piece left and right, leave unnailes about 2-3 feet from corner and use your coped pieces to adjust you setting on the wall. Lastly, if you have a long run 10 feet or longer add 1/8 inch and bend crown in the middle and allow it to snap into place.
