Attaching seat to chair apron

I’m surprised this slipped through the LJers grip. Normally there are an abundance of answers to a question like this. Anyhow, some material is more stable than others. For instance bubinga is very stable in service, but maple will move all day long. It could be somewhat difficult to answer the question because you don’t have a design posted or explained. Since you are using aprons however, their grain will be running left to right, and the seat will be going front to back. This means that the apron cannot move with the seat, and therefore some sort of alternate method needs to be used to fasten the seat. There are many ways. Figure 8 fasteners are nice, but they are metal. (you would never see them unless it folds somehow exposing the bottom). There are z shaped fasteners where you need to run a groove in the apron. One side of the fastener fits into the groove, while the other accomodates a fastener to the seat. You can make these out of wood. You could also use pocket screws and widen the holes. Or run stretchers horizontle fastened to the aprons. You would then use a regular fastener in a widened hole.
Essentially you just want to make sure the seat can move width wise, so it will prevent cracking, etc.

Hope this helped.

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