At this point a careful study of the detail drawings of the door corners will save you time, energy, and even money. Saw your storm sash or “Y” rails to the correct over-all length first Note that the channel section of the “Y” rail which slides over the bottom track has been reduced to 1/4 inch and that there is a -inch space left between the top of the upper “Y” channel and the upper track.This will enable you to remove and install doors whenever you wish by simply lifting the doors up and pulling them out at the bottom.
This bottom “Y” rail can be sawed to the correct width on a table saw and then sanded. It can also be run through a planer-jointer a few times (if such a machine is available to you) to secure a true or straight edge. If necessary, of course, a hand saw and a plane can be used similarly for this purpose.
Mark and saw your comer miters next. These corners can be sawed on a table saw or with a hacksaw. Once the corners are sawed and fitted together they can be marked for drilling.
The pair of rails lettered “A” in the drawing can be marked, centerpunched, drilled, and riveted together before the comer joints are drilled and riveted. The same procedure can be followed with the pair of rails marked “B” in the detail drawing. You can use a C-clamp or wood screw to hold the rails in position for drilling. Any vise will do the job, too.