You can use "screen" molding or "parting stop
" or just rip a strip from a wider board to 1/4 in.
Measure all the way to the jamb, not the blind stop or parting stop (see Fig.
Start your replacement insert installation by removing the interior stop, sash and parting stop. The parting stop is usually caked with paint and difficult to remove.
You have to pry off the stop (carefully for reuse) and the parting stop (which you can discard; see Photo 3).
OR PRY the parting stop from the groove in the window frame and discard it.
2 PULL out the parting stop if you want to replace a cord in the upper sash.
Then cut and install the new parting stop, securing it with a couple of 1-1/4 in.
Then pry off the stop and remove the inner sash, the parting stop
and the outer sash so you can strip the paint from the sliding surfaces.
1 REMOVE the existing parting stop
. Don't break this piece of trim; you'll reuse it.