The Green Science Alliance has set a goal of replacing chemical products with those derived from plants and natural biomass.

Perfect Repair: Metal glue is a high strength epoxy adhesive used as an alternative to torch welding, providing strong and durable repairs to metal and several other surfaces, forming a strong and ...

This included everything from epoxy to wood glue and various adhesives for plastics TL;DR: Some superglues seem to weaken PETG, and a construction polyurethane glue is the absolute winner.

He used several different types of glue including epoxy and superglue. You can see the video of his results, below. In addition to the glue, he used epoxy and bulk carbon fiber, again, in two ...