by GreenLake » Sun Dec 25, 2022 7:27 am
The way I understand it, adding a layer of fiberglass on the outside (top) essentially just repairs the skin. It adds a little bit of strength in areas where the new glass doubles up on existing laminate, but you are down to just the new cross section at the crack itself.
A stringer is more of a 3-D element and gains its stiffness from the separation of its top and bottom skin. Adding a stringer thus adds a lot more stiffness.
There are two considerations: one - do you really need the added strength / stiffness? Is this a '60s model DS1 or one of the newer ones? I know the laminate on the seats on those original DS1s is not super generous. I've managed to puncture it. But I've never seen the kinds of cracks you describe and this is the first time I read about one. I step on my seats a lot, so I'm just a bit doubtful that this is truly something that needs preventative solutions.
The other issue is access. Getting to the underside of the seats isn't going to be easy. It will take more than one access hole and careful planning on how to get stringer in place and attached. If you're convince that the situation requires a stringer, I'd like to read what you came up with as an approach.
~ green ~ lake ~ ~