hot glue is for your kids arts and crafts. it has zero strength. superglue is better but not great either. to really bond pla into a single piece it should be solvent welded. go right on amazon and order yourself a small bottle of weld-on #4. get the kit with the needle applicator bottle. you will need one. its not an adhesive, just a solvent (methylene chloride) which melts the plastic together.