Boolean operation isn't working

I have two surfaces that I want to join. I tried all boolean operations but all failed. Also, I tried Intersect then used the resulting curve to trim/split, this didn’t work either. Any idea is appreciated.Projectd_boolen.3dm (17.6 MB)
File attached.

the grey surface is self intersecting, and it seems you partially split it already. you may have to rebuild it that the top part does not twist like that then try again.

Wow, I didn’t notice that the gray surface is self-interesting. Thanks! I rebuilt the surface but I’m still unable to boolean them in any way. Here is the updated file Projectd_boolen.3dm (14.8 MB)

ok, now comes the tough part. since your model is very messy its going to take a bit of rebuilding it. you have shapes with different density. and also that joined orange polysurface is self intersecting somewhere on the bottom as i just found out.

i got the grey surface to trim off the inclusive parts after i rebuild the surface to a higher point count in the u direction. but the orange one gave me a hell of a work and since my computer is 7 years old i leave that to you again :smile:

i would anyway recommend to loft the orange part trying to keep the density a bit lower. if you have original curves take those and see to it that they have a low point density or use rebuild, or you use duplicate edge and frame the whole structure it will extract all curves just discard the ones running up vertically and then use rebuild. do that on each relevant curve to lower the density that the curves keep as precise as you need and loft.

when you do that, either you loft each segment and join the whole structure together or you do all at once but you have to make it in a chronological order also because they are vertically overlapping, so just selecting all automatically may cause the order to break and create you a weird surface.

if you cant get ahead anyhow and this is the only help you can get then i will try to help you further. but till then try to make a cleaner structure.