A Window Sash Milling Sequence

Updated: Jun 26

An order for twenty eight window sash, fourteen 8 lites and fourteen 2 lites, is an excellent opportunity to let our readers in on as much of the process as we can communicate.

Rotten windows in the background in need of repair
Me, standing in front of some of the sash I am remaking

Yesterday I milled up most of what I call blanks. Blanks are the properly sized pieces of wood, out of which the sash will be assembled. The blanks have to be the proper thickness, width and length before they can be taken to the next stage - joinery. Joinery is the art of connecting the blanks through various techniques like the mortise & tenon or cope and stick.

Making window parts requires a stack of rough lumber sufficient to make the parts. Rough lumber is not like the lumber people get at the home store. That stuff has already been planed down and smoothed out. Rough lumber is just that. Rough. It isn’t called 2x4 or 2x6 or anything like that. It’s called out by identifiers like 8/4, 6/4, and 4/4. That’s two inches thick, an inch and half, and one inch respectively.

My favorite tool to cut rough lumber to rough length is the circular saw. I typically cut my rough lengths about four inches longer than my finished length. The finished length is the actual length I’ll need to make a particular window part.

Once the rough lumber is cut down to size in what could