There are numerous places on the forward seat where bolts pass through or things are attached to it. For example, the rear rudder pedals and pulleys for their cables are mounted on the forward seat.
In order to provide enough strength for these attachments, and also for the bottom of the seat where the seat itself attaches, I added a layer of fiberglass mat and a layer of cloth to strategic areas. The pictures show the lower and upper areas of the back of the seat after this has been attached.
Once I determine the exact locations for each of these holes, I will remove some of the foam and replace it with a microballon-resin slury mixture, typically about 1" or so in diameter. This creates a hard-point for mounting so bolts or rivets won't crush the foam interior.
