Replies

1. 
   Guest_ | Jun 13, 1999 06:26pm | #1

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   Jim,let me just get the trim carpenter's rule book out,looking... nope, no rule you can 45 or cope. Whatever works best for you is acceptable.I've always found copeing to be tighter and cleaner because most inside corners aren't true 90's.Vince

1. 
   Guest_ | Jun 13, 1999 06:41pm | #2

   *Jim, I'd cope those corners. A key is to make sure both the butt run and the mating cope are perpendicular to the floor and to each other over the height of the base ... some shimming may be needed. For a tight fit, make the plumb cut of the cope on your miter saw, and finish the profile with a back cut using your coping saw.In this area, inside miters are viewed as short-cuts for low-budget work. Practice coping on scraps ... when you get the hang of it, you'll have an added measure of pride in your work and satisfaction in the skills you've gathered.Good luck, Steve

1. 
   Guest_ | Jun 13, 1999 08:52pm | #3

   *It doesn't matter. MDF will shrink and since it comes in shorter lengths and you have to join in long sections...it will look horrible. Just hack it in. If the owner cared he'd have supplied you with proper trim in the first place... Near the giant tube of Dap...L

1. 
   Guest_ | Jun 13, 1999 08:52pm | #4

   *Jim - Like Steve says, coping is often considered one mark of a Craftsman, since it is the traditional method for inside corners. Your work will be judged by by other carpenters, and lay people "in the know" by many things. When it comes to trim, coping is one of them. But what really should matter is how the joint fits, looks. Here is how a coped joint is BETTER.Wood moves. Virtually every stick you nail up will absorb and give off moisture as seasonal humidity changes. This will make those sticks swell and shrink, across their width, and along their length.When you cope a joint, the first stick goes all the way to the wall, right? So when the piece that abutts it shrinks, and pulls away, there is still the same profile behind the crack when viewed from the center of the room. To see the real crack, you would have to put your head right up against the wall.When you 45 that same joint and the boards shrink away from each other, you see all the way "through" the crack from the center of the room. Plus, you have twice as wide a crack, since both pieces are shrinking back away from the joint.Either method can produse good looking joints initially. I think the coped joint has a better chance of looking good 50, 100 years from now. And, as hard as I work to do my best, I sure hope after 20 years folks don't have to tear out my work and do it over. - jb

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   Guest_ | Jun 13, 1999 10:36pm | #5

   *The first house I ever trimmed was in 1971. I was real proud, but I still remember the rest of the crew laughing at me when they saw my 45ed inside base corners.

2. 
   Guest_ | Jun 13, 1999 10:51pm | #6

   *I'll go along with everything Jim said plus one more reason to cope . That mitered joint may look and fit swell UNTIL you nail the base a few inches from the corner and find the drywall wasnt pulled up tight to the bottom plate resulting in a crack you could throw a cat thru. Believe it or not I've seen drywall hangers who didnt put any fasteners in the last foot or so near the floor ,saying the base would hold it . What little mdf moulding I've used came in sixteen foot lengths [not what I would consider short ] and the only shrinkage problem I've had was when I used moulding from a yard that stored it outside in a covered shed . It shrank enough to crack the paint on mitered casing .The stuff I've used from another supplier that kept it inside like they should hasnt shrank after more than two years . Chuck

3. 
   Guest_ | Jun 13, 1999 11:00pm | #7

   *I cope all inside corners as well but a good miter will probably look better than a bad cope. If you dont have the time or desire to learn how to cope then miter them. MDF is not my favorite either but it does come in 16' lengths here and doesnt shrink as much as wood. You did say that this is your own nhouse so if it looks good to you nobody will ever know the difference. If you were trying to build a reputation as a good trim carpenter things might be different. MDF can be hard to work with as trim but if done carefully it will be hard to tell the difference from wood.

4. 
   Guest_ | Jun 13, 1999 11:21pm | #8

   *Jim, Like everybody else, I too am in favor of the cope over the mitre. We put up a lot of very large decorative ceiling moulds that roll flat at he top and therefore cannot be coped. A good mitre gage will tell you how many degrees of splay you have and you can adjust your mitre accordingly. Although these mouldings can't be coped, I have never had one fail. ( always glue the mitre joint. ) I have never seen a piece of MDF moulding down here, and I hope to never see one. But I would be inclined to think that it would not shrink or expand significantly because it's not grained wood. I had a carpenter who worked for us who used a jig saw held upside down to do his coping. It had a special shoe on the bottom of it made for that purpose. He could do beautiful work with that method. I've never tried it, but as I own the company, I don't get to do that much hands-on work anymore anyway. If it were my house, I'd probably just 45 the corners and let it go. If the house is well framed, you shouldn't get much movement in the walls. Ed.

2. 
   John_A | Jun 14, 1999 04:18am | #9

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   Jim,
   I've also had better luck with 45ing or what ever angle applies, when using mdf.

   It's very hard to not damage the piece when coping, which is the method I prefer 90% of the time ,but not mdf.

   I have trimmed 3 houses with it now, and like it a little more each time.

   What glues have you guys used ? I have used regular yellow, one of those miracle glues that supposedly works on every material,and even tried white elmers in inconspicouse spots to test it.
   they all worked good but,I don't know about long term (movement or setteling)

1. 
   Greg_Booth | Jun 14, 1999 04:40am | #10

   *While installing some 3-1/2" stain grade crown I stumbled on a method to mark the cut line for coping it. I set the miter saw at the correct degree of miter and bevel for an inside miter cut and the cut line on the face of your piece is a perfect scribe. Lots easier than holding it up there at the right angle to scribe. All that's left is to remove the wood from the backside of the cut so the other piece can run by. Depending on the thickness of the material you can pick your weapon of choice, I usually grab a 4-1/2" grinder and finish with a file if it's really convoluted.

1. 
   Rich_B. | Jun 15, 1999 09:46pm | #11

   *Jim,I too am a homeowner who did my own trim. At first I used the 45 method, and many joints required multiple cuts for all the reasons posted above on loose drywall, out of square, etc. But then I built a jig I saw in one of the tip books, which was like an A-frame. First I miter the 45 end on the workpiece to make a cut line, then I rest the workpiece on the horizontal leg of the A, and using the vertical leg of the A as a support for my jig saw, cut to the line. This produces a back cut at 45 degrees, so that the thickness near the front is about zilch. In reality, I cut just short of the line, then use an assortment of files to get to the line. One of the neatest things I got was an air die grinder (the $20 variety) with a tapered rough cutter. This gives me any radius from about 1/16 up to 1/2. After all this, if it still isn't perfect, a few taps will crush the thin end right into the adjoining piece for a perfect fit.Good luck.

3. 
   Guest_ | Jun 15, 1999 10:03pm | #12

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   I too use the "cope it a hair long and tap the end grain in" method. It works well even on prefinished pieces.

   -Rob

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   Guest_ | Jun 16, 1999 07:33am | #13

   *Jim one thing no one seemed to mention was what type of coping saw blade you are using ??? I have found with MDF that a fine blade with at least 20 points per inch works much better than my standard 15 per inch blades . Just a thought Stephen

1. 
   Guest_ | Jun 16, 1999 08:16pm | #14

   *Hey Jim:Gotta love this BBS huh?I wouldn't cope MDF under any circumstances. Paint grade trim isn't worth the effort. Just slap some Dap on the corners and call it a day.Stain grade trim is a whole different deal, and I would definitely cope it. You can't learn to cope in two trys.Back cut a mitre. Rub a pencil on the edge, and take hand coping saw and practice. After about 20 copes, you'll get the hang of it. After about 50 you'll be the man.You can try a jig saw for the copes, and that is faster, but mine likes to take off, and if it wanders, I've ruined a nice piece of trim, that comes out of my profit.They make a rounded base for the Bosch jig saw, just for copes, and that could help, but I have not used it.Do any of you guys use that new base?

1. 
   Guest_ | Jun 16, 1999 08:39pm | #15

   *ScooterSo what is a kitchen torch?Scott

1. 
   Guest_ | Jun 19, 1999 06:17am | #16

   *I also cope most of the inside corners when doing baseboard. When I run base on walls that come together at a 45 degree angle(inside corner) I miter two test pieces base at 22 1/2 degrees. I put two screws behind each piece. One at the top of the base and another at the bottom. I take the two test pieces and see how the joint works. I tighten or backoff the screws to make the joint better. I use the screws as shims because the drywall in these corners is always lousy. When installing the final base I glue and put some adehsive behind it. I haven't used MDF before and like Dallas hope not to see it. The screws in the corner may help when mitreing it in 90 degree corners or it maybe overkill.All of the outside drywall corners of the homes in my area have round corner bead. It is either 3/4" radius or 1 1/2" radius. The outside corners of base board have a third piece in the middle. All the mitres are about 22 1/2 degrees and there are four cuts. I have a pretty good method for this base detail but i would like to hear how you guys do it. Thanks Dave.

2. 
   Guest_ | Jun 19, 1999 06:26am | #17

   *Jim,

   I hope however you did it. . . It's done by now.

   Joseph FuscoView Image

3. 
   Guest_ | Jun 22, 1999 06:12am | #18

   *Jim,I cope 'em ,but go with what works for you.There was an article in FHB awhile back (cant remember the issue) that showed an interesting base detail utilizing corner blocks try searching for it, maybe that might work for you here.

4. 
   Michael_Roraback | Jun 23, 1999 06:28am | #19

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   Boy I don't know where to begin with this crap! About 8 months ago, I was approached by some people I know. They asked me if I was interested in trimming out there house. I said sure,Besides, maybe I could get my hand into there neighborhood,they live in greenwich Ct. I thought it would be a great opportunity. Well when I got down there, I found that they had bought that crap for me to install. I pride myself on the quality of my work and found myself frustrated when I tried to do copes with that stuff. I also found that 45's with it worked and looked better. Also, when I do long runs with molding, I 45's on the butt joints. This looked like crap with the mdf. So I tried just butting them um with a good square cut, it looked better. My friend pat asked me why I looked so frustrated, I told him why did you buy this crap? He said that all the more expensive houses down here used it. I said that I would rahter not work again then to install this junk. Where has the quality and pride of carpentry gone? I constantly ask myself that question!!!!!!!!

5. 
   Guest_ | Jun 23, 1999 08:10pm | #20

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   This is an intriguing question. When I started trimming in 1973 we had mostly 1 ½ streamline or beveled casing to deal with. Most of the time we used a small home made miter box made from a 2 x 6 around 18 inches long with pieces of 1 x 2 nailed to it on each side. Then two slots were cut for 45 degrees plus one for the square cut. I used a short Stanley saw to make the cuts right there in the room where the base is being laid. We definitely did a coped corner connection because there was no way to be able to cut the corner’s angle accurately on the two connecting pieces. Coping was a must.

   When I finally got a Makita 10-inch miter saw in 1980 it opened a whole new process to me. That is when I also increased my speed when doing corner cuts. The problem I had at first was realizing just how out of square many of the corners were, both obtuse and acute, and few to be found to be a true 90 degrees. So that was also the time I purchased a speed square and started using it to pre-check the squareness of the corners and, depending upon the size of the base material, the plumpness of a corner too.

   I like MDF material simply because of how clean it cuts, its consistency and how smooth a finish you can have when its painted. However I do hate the spaghettiness of it and how easily it is damaged if not handled carefully.

   I’m doing a job at the present time where the base upstairs is 1 x 6 MDF with a very active 1½ -inch trim decoration added to the top of that. The downstairs is 1 x 8. That material is butted but the trim on top is all mitered and tight. I can’t even imagine daring to try to cope this trim material. It is fat, then thin, fat again and pitched. Its as French and gaudy looking as the Architect could find in his book from the molding supplier.

   So if you learn to use a speed square to determine the true angle of the corners, have a saw capable of cutting 4” base to the exact ½ of the corners angle, compensate for any out of plumbness of the corners and have the MDF tempered to the house then by all means miter the corners if you like it better than coping. ( < Obsolete Link > Dale Williams "Crown Moulding fiasco!" 6/20/99 11:53pm )

   If the MDF has been tempered to the house there is very little shrinkage with it. I did pull some crown molding off of one job after it was installed and had shrunk. The new material didn’t cost me anything because the supplier took responsibility for having told me it wouldn’t shrink. I could have left the other material up and recaulked it but it was the principle of my jointery not being tight that bugged me and not the homeowner. The new material has as yet to shrink after 4 years and it was installed with mitered cuts.

6. 
   sysop_ | Jun 24, 1999 01:47am | #21

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   this should fix it, dale.

   < Obsolete Link > Dale Williams 6/23/99 11:10am

7. 
   Guest_ | Jun 24, 1999 03:53am | #22

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   Cope the cornors, with MDF you have to change your angle for the cope. When you cope wood you "lay the coping saw over" around 45. With MDF you have to use a shorter angle.

1. 
   Guest_ | Jun 24, 1999 04:09am | #23

   *Why, Bill? It seems the usual 45 degrees would lead to the desired profile. (I'm inexperienced with MDF)Steve

8. 
   Jim_in_Ontario | Jun 24, 1999 04:11am | #24

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   I am trimming our new house. I am using 4" MDF baseboard and having a hard time coping(physically and mentally). I tried 2 inside 45 degree cuts and it looks so much cleaner than the copes. Would it be wrong to continue with this method? Why does it seem that coping is the proper way? It is a nice house, and if coping is the professional and proper way, than I will but if 45 degree cuts are also okay, I'm more comfortable with that. Thanks, Jim in Ontario.