What is fusion welding?

So fusion welding means that the corners themselves are not screwed together.

So an all-fiberglass product can't be welded.

It has to be mechanically screwed together.

So decades ago, when, uh, I was in the aluminum window industry initially, um, you know, those windows, you- they weren't welded.

They were literally, uh, glued and screwed together in the corners.

Uh, well, the problem with that is they leaked.

Okay