Proper Angle for Coping Cut

I am wondering if, when making a miter cut to expose the profile of a baseboard, if 45 deg. is always the best angle, or should one adjust it a few degrees either way?

I am putting in some oak baseboards, where I don't have the luxury of using caulk and paint, and the curved tops of the baseboards don't always fit exactly. I am wondering if adjusting the miter angle would help, of if there is some other trick to making the profile match the baseboard better.

Reply to
Buck Turgidson
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Buck Turgidson apparently said,on my timestamp of 3/08/2004 10:16 PM:

You might need to cope rather than mitre. See here for examples(watch for URL wrapping):

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your stock is not perfectly dry or the weather is changing wildly, you may find thinner portions of the baseboard profile opening up a bit. This is normal and can't be avoided. Unless you cope rather than mitre. And that is a bit more work. Worth it, IMHO.

Reply to
Noons

45 degrees is correct if the corner it is fitting into is 90 degrees. the corners of rooms often aren't right at 90. a degree or two won't make a visible difference on a cope joint with most profiles, but keep it in mind.

more important to getting a tight fit is to back cut the cope. that is, when following the profile with the coping saw, cut a few degrees beyond square to the wall, so that inside the joint, against the wall there is a little gap but at the face the joint snugs up tight.

Reply to
bridger

Noons...

read the subject line....

Reply to
bridger

Hey Bridger -

I think Noons got it right - the subject line indicated the OP was talking about a coping cut BUT the content indicates he was talking about a miter cut. From the body it sounds like he doesn't understand what a coping cut is.

Just MHO -

Vic

Reply to
Vic Baron

Vic- the first cut you make for a cope joint is a miter to as the OP put it, expose the profile. then you follow the exposed profile with the coping saw.

here's a page that shows it pretty well:

Reply to
bridger

I'm aware of how to make a coping cut, Bridger - I just don't think the OP is. Since you make the miter cut to expose the profile and then use the coping saw, it really doesn't matter. The angle at which you cut the profile with the coping saw seems much more critical.

The OP indicates that the "curved portions" don't fit and would changing the miter angle make a difference. I still don't see that he understands a coping cut.

Reply to
Vic Baron

Or you don't understand geometric projection. Changing the angle changes the exposed profile. A couple of degrees either way shouldn't change it enough to notice, but should and does are not always the same.

Reply to
J. Clarke

You are correct, but it can make a difference with wider molding with a deeper profile. Especially on an old house, where nothing is 90 degrees. Cutting the original miter a few degrees more or less than 45 can make the cope easier, and require less fine tuning with files or rasps.

tt

Reply to
Test Tickle

I understand geometric projection better than you might think - I just don't know how to read .

I re-read the OP and FINALLY saw that he was referring to the profile - duh!. Y'see, the way that I make coping cuts it to cut the 45 degree miter but slightly undercut the 90 degree coping cut. Allows for a tighter fit and a *wee* bit of misalignment in the corner. this is also assuming we're talking about a 90 degree bend here,

Apologies Bridger - you are correct - I've been sniffing too much Cocobolo sawdust.

Vic

Reply to
Vic Baron

Something that I often do in this situation is to rip the profiled top part of the baseboard off on the tablesaw.

This allows me to run the flat part of the base around the room very quickly, using butt joints on the inside corners.

The profiled part is much easier to cope when detached from the flat.

One thing that you might want to think about is the order in which you apply the pieces. Most rooms have a primary direction from which things are viewed.

Let's say you have a room with a fireplace on one wall. In most cases the furniture will be oriented so that people can view the fireplace. In this case I would run the baseboard on the most viewed wall area first and butt the flat into that and cope the top profile on the piece that runs into that wall. If your copes are a little off they will not be as noticeable this way.

Also, take some time to check the inside and outside corners with a framing square. Many drywall tapers leave the mud fat on the inside corners, particularly so at the area near the floor. You can save yourself some trouble by sanding out the mud in the corners with some eighty grit paper before putting on the base.

On the outside corners the mud is often concave from the high point established by the metal corner bead to the flat of the wall. It is often worthwhile to run some more mud in this hollow to get things flat.

Remember to hold your base up so that the bottom is a little bit above the finished floor line, if you will be using a quarter round, or just slightly below, if not - this will avoid burying the nice trim that you bought in an area that can't be viewed. If you are applying the base to an existing hardwood floor, I'd rip a back bevel on the bottom on the tablesaw, so that the point can provide a crushed fit to the flooring - most floors are a little wavy.

You are right on in thinking that a back cut forty five is what to use as a coping guide on an included ninety degree angle. I undercut the cope piece a good deal and leave the other end square, so that I can tap the joint home with a mallet - biting the sharp edge of the cope into the other mating profile. Then I cut the square end to a miter before nailing things home.

The outside corners are more fussy because the corner bead is always out of plane with the wall. Running some mud into the hollow will help but won't eliminate the problem.

I usually cut test pieces at forty five and a bit off of this and then see which pair works best on the particular corner. If I only have to walk to the SCMS three times to get the right fit - I consider that about average.

Good Luck.

Regards, Tom.

Thomas J.Watson - Cabinetmaker (ret.) tjwatson1ATcomcastDOTnet (real email)

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Reply to
Tom Watson

Reply to
Daniel

Is this the same Nuno who hangs out in the Oracle group?

Reply to
Buck Turgidson

I haven't been available to jump in and clarify, but, yes, I am just wondering if adjusting the 45 by a degree or two will sometimes make the coped profile fit a little better, since the curved top of the baseboard isn't always perfect. I cut at 45 and then flip the piece over and back-cut at 45 down to where the profile starts to curve. I am just wondering if 45 is a hard rule.

I guess I'll experiment with scrap and make a big pile of sawdust tonight.

Reply to
Buck Turgidson

I think he has a basic understanding of it but is having some trouble making it work. the question of whether the angle of the first cut matters is a valid one, and the answer is not too much. it *does* matter somewhat, though, 'specially when a corner is way out of square and/or when the molding has a deep profile.

Reply to
bridger

increasing the angle beyond 45 will exaggerate the profile, decreasing it will flatten it out. if you're measuring from the corner and using that number for the final length note that changing the angle will change the length.

Reply to
bridger

there ain't two of us anywhere else...

Cheers Nuno Souto snipped-for-privacy@yahoo.com.au.nospam

Reply to
Noons

Check out Vic's advice above. That's the way I cut them as well. The undercutting seems to correct for slight mistakes or misalignments. At least it works for me... Sorry I misunderstood your first post.

Cheers Nuno Souto snipped-for-privacy@yahoo.com.au.nospam

Reply to
Noons

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