Avoiding faces clipping through surface when animating

Hi. So I have a character, more of an armor set. I used solidify on a lot of parts, such as a waist coat, shirt sleeve, etc. The helmet most of all, is what I’ll be talking about. Unfortunately, I think I messed up. Whenever I move the mesh by rotating or moving a bone, the “inside” faces come through. No matter how much weight painting I do, I can’t make it perfect. There’s always some spot that clips through.

Is this normal? Some things I did differently, for example on the gauntlets, I “closed” the end, so there aren’t internal faces and therefore no issues, I didn’t even use solidify. But with a belt, even with no internal faces, it’s thin enough that the other side might clip through sometimes. How can I avoid this in the future?

Here is an example, on the belt and sleeve. The opposite/inside faces are peeking through. Should I have just left these things as flat planes? I was getting an error applying them to the armature, because planes are non manifold. I used solidify to remedy that.

Use a mask modifier on the inside faces or delete them if you don’t need them.
Concentrate on weighting the “outside” mesh to move how you want.

I will look into this. The reason they’re there in the first place was because I read that non manifold geometry was causing errors generating the weights. And then of course, some parts need to have some thickness.

I’ve found a way to stop this from happening, I just have to do weighting before applying solidify. Then when I apply Solidify, the whole mesh has equal weights on “front and back”, so it doesn’t have this clipping.