Nomex Wet Layup Technique
I'm part of a prototype car team that makes their chassis out of carbon fiber. We've run into a lot of problems when making the lower body of the car, especially with choosing the right sandwich material for our stackup.
Last year, we used Nomex (cardboard honeycomb structure, 1/8th inch thick) as our sandwich material, and did 3 layers carbon fiber as the base layer, and 3 layers on top. For the layup last year, we cured the bottom layer first, then put the nomex on top of that, and then coated the top of the structure with epoxy+filler, then re-layed up with carbon fiber. The carbon fiber had a hard time sticking to the nomex structure due to the lack of surface area, and I'm unsure if some of the resin travelled into the nomex structure.
We use dry carbon fiber, and we use room-temp curing epoxy resin, and we're not looking to using prepreg, and prepreg adhesive films lowk too expensive for us (we're on a budget).
What can we do to improve carbon fiber layup for us? Do we cure both the top and bottom parts of the sandwich panel, and then do the layup for the nomex separately (with the filler)?