I have 2 different parts that I would like to weld to make a second part and not an assembly.
This part is intended to be 3D printed.
I have already tried it as a simple assembly composed of 2 pieces by cheating on the ribs believing that they would be joined together but it didn't work.
Are the 2 pieces in 2 independent prt files? If so, you can import them into a 3rd part file (insert/part). You can then add material where necessary to be able to merge the 2 bodies.