Secure window sil for barn workshop window

[Dave Rosner]

Hi all - I just added a window to the workshop in my barn where I plan to build the mother of all workbenches - figured the natural light would be good there. I've never framed a window before but figured out most of it.

For the sil I milled a piece of 1x8, notched it, and then put the right angles on the exterior and interior lengths to match the old barn window sash I salvaged.

So all is well...but how do I secure the sil to the rough framing I did? I could stick some small wedges of wood but it doesn't seem too secure. Shims don't seem to have the thickness for the angle either. I looked at cutting some wedges but the angle is so shallow (15deg?) I can't do it on my Tsaw, band saw, or Miter saw.

I've been looking around the internet and for a formal house window I'd have an interior sil called something else and an exterior sil and that might make things easier. In my case I got a simple barn and framed in a window using 2x4s.

Any suggestions for how to secure this angled sil to the rough frame?

[Bill Dufour]

window sill is normally 2x6 redwood. Older house may have it milled into a wedge shape or just up on a strip on the inside. Easy enough to rip the 2x edges to the correct angle so they will be vertical after installation.
Bill D.

[Jim Andrew]

The sill is usually part of the window unit. What did you use for a window?