[Solved] Booltool union going very wrong

I don’t really understand what’s going on here. Any clue?

Edit: oh, it turns out that the boolean union on the other arm wasn’t without its deal of problems – it created inside geometry, those lumps that remain when the operation is completed in the animation. Removing them with the “select by trait” feature in edit mode solved the problem.

If you’re just creating your initial shapes, I suggest using voxel remesh tool in Sculpting mode (It joins the mesh, removes problematic inner faces and makes it “water tight”).

thanks for that input, I will try it on my next project! It sounds immensely useful