I am personally a fan of doing both of these
- Plastic weld the pieces together (embeds pieces of metal into the prints across the seams) - Link
- Resin + Fiberglass the inside
I only did the resin and fiberglass on my MKVI suit and it seems to be holding up pretty well.
I plan to do both, and an external coat of resin, just like [USER=19020]TurboCharizard[/USER] does on his suits when I working on my MKVII suit.