Hello,
Thanks for your follow-up! I cut (wet tile saw) 3 rocket fins out of the purchased plate and used a high quality epoxy to bond those fins to the airframe of my rocket. Then, sanded, cleaned (lint free cloth and acetone) to achieve a good "water break" surface on all six faces (both sides of 3 fins) of the fins, along with the relevant section of Carbon Fiber airframe. Then went through the wet lay-up process (3 layers @ 0 degrees, 45 degrees, and 0 degrees) with the cut Carbon Fiber fabric, using West Systems resins, and finished with High Temp (450 F) perforated Release Ply and Breather Fabric, before bagging. All done at a cool room temperature indoors! Waited about 4 hours for the resin to reach a "leather" texture, disassembled the set-up and stripped off the Breather and Release Ply. Frigging awesome result!!! I achieved exactly the finish and final thickness I hoped for on the fins. Will certainly require some finish touches on the leading and trailing edges of the fins for optimum aerodynamics, but that is easily accomplished. As you mentioned I can see that the very best final finish will require wet sanding (800, 1000, 1500, 2000 grit is my plan), finished with a hard clear coat. In the rocket business smoother is faster, and faster is higher!
Fortunately, I did a LOT of preliminary work to ensure a reasonably smooth process. Did EVERYTHING possible ahead of the layup, and practiced the process over and over prior to the actual execution. The use of electric scissors, and 3M 77 on wax paper to keep the cut pieces of carbon fabric from separating was pure genius! A 2nd person to mix resin and hand me the cut sections of carbon fiber fabric (on wax paper), orientated correctly, was super helpful.
It took me way longer to build the wood jig for the lay-up procedure, along with the vacuum bag, than the lay-up and bagging process itself.
My original question was just too basic, as it was obvious that a smooth surface like the Release Ply would certainly yield a better finished (smoother) surface than the Peel Ply. My trivial question was probably a waste of time to your community!
Regards,
Gary