how can i close this surface?

i design this surface and joind them together but when i do "close surface" catia shows me this error and when i do "boundary" catia shows me this lines that tells me my surface isnt closed! what can i do do close this part? whats the problem with my design?

1 Answer

Use Healing to close that surface. That tool is located right under Join. You might have to increase the merging and/or distance parameters until the green lines disappear.