Odd angle miter cuts

[Martin Anderson]

I am trying to wrap chair rail around a corner that is not 90 degrees. It measures out to be 86 degrees. The problem is when I set my miter saw to cut what I think is half the angle (43 degrees) and the two pieces together, the sum of the angle made by the two pieces is greater than 45 degrees...its more like 51!
What gives? How do I cut chair rail to accurately fit around a corner that is not 90 degrees?

Frustrated in Massachusetts!

[Bob Herpolsheimer]

It's more tedious but a cope joint is a good way to go for chair rail.

[Scott Loven]

You will seldom find anything in home construction that comes out to exactly 90 degrees!
put a piece of molding on the floor, up against the wall, over a piece of paper if you want and trace an inside and out side line of the bottom of the molding. Do the same from the other wall. You should have two sets of intersecting lines. Draw a line from the inside intersection to the outside intersection. This will be your miter cut. Cut one side of the molding. Use the opposite angle to lay your cut out for the other side. Use a piece of scrap molding to test the cut first. Use a hammer to conform the molding intersection if not perfect.
Scott

[joe greiner]

Hard to tell where the 51 came from, but it sounds like you might have set or measured or interpreted the angle wrong. Is the 86 degrees inside or outside? If inside (sharper corner), CMS setting should be 47 degrees (measured from zero at perpendicular to the fence, i.e. 90-43=47). If outside (blunter corner), 43 degrees should be right.

To fine tune a miter, clamp the pieces together in proper arrangement and run a hand saw along the joint. Parallel sides of the kerf will fit perfectly.

Measure three times, cut twice, sand to fit.;)

Joe

[Ben Grunow]

Sounds to me like you are working on an outside corner (corner that has a metal corner bead) and not an inside corner like the corner of a 4 sided room. Am I right?

If so then you should be cutting the pieces at 47 deg not 43. This will add to the long points of the pieces to get them to touch. Make short testers and work them until they fit and then cut the real ones.

It is more important to make a test cut than to know the angle because as Scott said.. nothing is ever 90 in a house.

Hope this helps.