To properly cut and install a detailed base molding at an inside corner that is not 90 degrees, how do I determine the angle at which to cut miter before coping the joint? It seems that a 45 degree miter doesn’t line things up correctly. All the references I can find only refer to a 45 degree miter, apparently assuming a 90 mdegree corner, and I’d like to avoid a hit or miss approach. Can anyone help?
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If the drywall or plaster is not plumb at the baseboard area, you might be able to drive a 6 or 8 common nail into the corner to keep the uncoped base from sucking to tight to the wall. If this is not an optin, use a bevel square and test the cut on a piece of scrap. For corners out of square,[over or under 45], I have found that a 45% cope generally works. If the wall is out of square more than 5%+-, use a test scrap.
Thanks very much for all of your responses.
Don't forget to cut the coped piece a little long so when you snap the piece into place, the cope crushes into place and should be tight and closed.
MJC Woodworks
"Gentle to the touch, exquisite to contemplate, tractable in creative hands, stronger by weight than iron, wood was, as William Penn had said,"a substance with a soul.'"
Eric Sloane
Most angles around 90 get covered with a coped 45. As has been said, plumb cut is another story. Cutting long and some form of shimming the offending pc makes it look good. On occasion, if you forgot to deal with the offending pc and it's nailed off, then guessing the distance off plumb and cutting it long also will bail you out.
There are a couple of angle gauges available (manual and electronic) but for base you should be able to hack and whack with accuracy once you get the hang of it.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Angle of the joint divided by 2? Could it be that obvious? I'd at least try it.
Jeff
Good answer if one isn't into coping. Like this Take a scrap of base and lay it against one wall as if it were being installed. Butt it into the corner and draw a line in the floor where the inside surface of the base touches the floor. Now do the same for the other wall. Mark your scrap at the bottom finish surface where the lines intersect while holding the scrap against either wall while it is butted into the corner. Take it to your saw and cut the angle from your mark to the butt end that you pushed into the corner. That will be exactly half of the corner angle.
They can't get your Goat if you don't tell them where it is hidden.
Your point that 'marking in place' beats measuring any day of the week is, of course, right on.
It's still the angle/2 - just a question of how precisely to get there.
Jeff
Nobody has come right out and stated the obvious here so I will. You really should forget trying to mitre this joint and cope it instead. If your angle is a little off of 90 degrees the cope is a much better way to handle it. If you insist on miter joint, put a piece of paper in the corner and trim it to fit the angle, then fold it in half from the vertex and there is your miter angle. Pre glue the miter.
Have a good day
Cliffy
Thanks. The angle is way more than 90 degrees (probably around 135 or so). I have proven that a back miter cut of 45 degrees such as I would use for a 90 degree corner, when coped, will not produce a fit anywhere near acceptable. I am guessing that a miter cut of 1/2 the corner angle may produce the result I seek when coped, but I've neeb surprised that I haven't found a single reference to thsi in any opf my reading.
I think you're asking a broader question that also is soon to affect me. How do you cope for 135 degree corners? Obviously, back beveling 45 degrees won't work. I think you need to back bevel 22.5 degrees and then somehow cope back from that. Depending on the thickness of the trim involved, that's going to be a pretty ambitious cut. Maybe using the angle grinder technique is the way to go?
Anyone have any advice?
Depending on the profile of course, an angle that big would require pretty severe backcutting to produce a good result in a cope. I'd be more than tempted to mitre it-fastening with glue and screw/nail from the backside and slipping the whole mess in.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Mark the cut, clamp a couple of scraps to give you vertical straight edges, use a sharp Japanese style trim saw to cut.
They can't get your Goat if you don't tell them where it is hidden.
If you have collins clamps dig them out. Cut the mitre, glue and clamp it for a couple of hours then slide it in gently and nail it with an air nailer.
Have a good day
Cliffy
Here's a straight-up way to find baseboard angles. Get two pieces of baseboard. Longer is better, but anything over 16" will work. Lay on them the floor, tight to the wall, and sribe where the top board crosses the bottom board. Find that angle on your miter-saw. Subtract that from 90 and divide in half.
If your using base-cap, add a degree or two for outside corners and subtract a degree or two for inside corners.
I'll try it. Funny how the best solutions wind up being the simplest.
The trick I described works like a charm for outside corners but, now that I've had some time to think about, I think you would have to ADD to 90 for an inside corner.
You are correct with your correction.
They can't get your Goat if you don't tell them where it is hidden.