What should never be done with your old, historic windows.
YEP, THAT’s wire
Well, it kept things sort of whole until we came along. This sash required reproduction, as the damage could not be restored.
AUTO BODY FILLER IS NOT COMPATIBLE WITH WOOD
What you see is auto body filler which tends to promote decay right where it connects to the wood. We do not use it.
that is too much grain
The long cross grain joint at the head of the sash is too much grain at 90 degrees. The cracks are due to shrinkage and the board is too wide not to be floating. This was from a well made building that otherwise had sound details.
This is, in contrast, an excellent detail, one we continue to use today
See the drip edge housed in the dado? It is a slot or trench cut into the surface of a piece of machined wood.