mitering 2 different widths of wood

[John Borgwardt]

I don't know if this belongs here but, here goes. I am building something that has 2 different widths of boards. I am trying to miter them together. How would one go about doing this? The corners do not appear to be at 45 degrees. Thanks John :confused: :eek:

[Doug Shepard]

Lay a piece of the narrower one over th wider one and butted up flush at the end then mark or knife a line on the wide one. Then set a bevel gauge across the diagonal of that end rectangle. It wont be 45 but the inner and outer corners will meet up.

[greg Forster]

Another method with equal length miters at 45*- cut the 45* miter on the narrow board, lay this on the wider board at 90* and scribe the miter onto the wider board. You will end up with a "squared -off" corner on the wider board and with the equal 45* miters a much better appearance if that is important.
I've seen this on 18thc work and it probably pre-dates the Grecian/Roman
construction.

[John Borgwardt]

I knew you guys would come thru. Thanks a bunch. John ;)

[Richard Magbanua]

If you want to figure out the angle for any miter you can trace each board on paper at the angle you need them, find the miter angle with a protractor and then use that to set your bevel gauge to guide your marking knife.
If you're techno savvy you can lay it out on Google SketchUp and measure the exact angle that way.
Hope this helps!

[Prashun Patel]

a=width of board A
b=width of board B

Miter angle of board A = arctan (a/b)
Miter angle of board B = arctan (b/a)