Do certain weak points need certain elements to do "weak point" damage?

[CultOfPersonality]

Example: King Yeti has that weak spot on his ass. Does it have to be hit with a fire element to do the weakness damage or no?

Can't figure out if I'm getting unlucky or what. I sold my fire weapon and its the only element I don't have since my others out-damaged it but I'm not sure with weak points.

[Ana-Chan]

It doesn't require the element to get access to weak points. But on weak points a weapon aligned to the element that it is weak against will do more than any other weapon.
An example is with a Catadoran, once you break the tail, that is a weak point. As a force, hitting it with the rod is usually something like ~120 per hit when the tail isn't broken to ~200 when it is. Techs have similar increases, and hitting it with say zonde for me normally hits for ~1200 and barta hits for ~1500. (Compared to 500-800 when it isn't broken). So no, a weapon being aligned to the enemies weak element just increases damange in general.

The king yeti though has an annoying habit of getting enraged and the weakpoint stops working if you kill any of the regular yetis around it.