Spent a very well-worth-it day learning about woodworking from the excellent Chris Tribe in Ilkley, who mainly makes high-quality furniture (and teaches other people to do the same) but agreed to spend a day talking to me about window construction.
In addition to talking a lot of theory, we also cut a piece of square wood into a shape suitable for use as a window casing, just to see how joint cutting works and to play with all the cool machines.
Starting with a square length, we used this excellent table saw (I really want one of these) to cut out a recess for the glass to sit in.
And then cut it into lengths suitable for working with on practice finger joints.
We then used a router table (I really want one of these) and a jig to remove all the bits of wood that shouldn’t be there.
For the mortice (if it were a mortice and tenon joint) we used one router bit, the name of which escapes me.
And, having done that and used a special measuring-marking-tool-thingie to mark the opposite piece, we prepared to cut out the other bits. It’s all very technical…
A different router bit this time, chewed away the bits from around the tenon.
This guy would never be short of sawdust for a composting toilet. Anyway, the two bits looked like this when apart:
And like this when together. I was fully satisfied with the fit, although Chris said it was a bit loose. Still, it was exactly as I would have expected it to work and I am planning to make all my own windows this winter.