Hello everyone,
I am building up my racing car and i am making all the pressure tubes in carbonfiber by hand layup.
The reason for this is that i have built a huge 3d printer which can print the exact pipe size and shapes i want.
All of this is already accomplished with succes.

However now i am standing at the finishing part of the tubes and some weird patterns shows up after sanding the surface.
I am following the carbon skinning tutorial and only replacing the XCR epoxy with the EL160. Postcuring has been done to 40ºC so far and final temperature is going to be 170ºC.
The post cure cycles will be followed to 170ºC and polish after that when everything works on this test piece.

My process so far for this tube:
1. Glass fiber hand layup of the tube with EL160 post cured to 170ºC (Glassfiber is just better here)
2. Sanding 120grid
3. Carbon sleeve hand layup with EL160
4. 24 hours cure +25ºC
5. First sanding down dry 120 grid
6. Surface cleaned with brake cleaner (Alkanes)
7. 3 coats of EL160 was applied by waiting between passes approximately 6 hours until sticky "B" stage.
8. 24 hours cure + 2 hours 40ºC cure.
9. 180 grid wet sanding + 500 grid wet sanding + polish some places.

Please see pictures of the imperfections shown best before the polish process.
It is like the layers is not properly bonded together.