I am building an underwater ROV and have 3D printed thruster shrouds and props in yellow Hatchbox PLA. They did not handle the vibrations and power from the motors very well and split along the junction of the mount and shroud that were 3D printed. To put them together I used 2 part epoxy rated especially for water, but 2 of the 4 have already broken along the glue line and some of the props are also shattering too from the stress (Fully 3D printed with no glue used for the props). Maybe using an epoxy is the wrong glue with the PLA, but I thought this would be the strongest I could get since CA is very prone to cracking with the vibrations.
So is there a better glue to use to fuse PLA together than H20 hold epoxy?
I am also thinking maybe I should use a different filament that would especially handle vibrations and have the strength for the 1 to 2 kg of thrust I am producing on the ROV props (This thrust is just an estimate, I have not measured it). I thought maybe yellow PETG would be a great compromise having the strength of ABS and have the ease ability to print of PLA, but I was not sure if anyone had a great suggestion of what yellow filament to print them in. I figured if I changed the props over they would be stronger and hold up much longer. It is also a little scary to test out a prop with the chance part of the blade might come flying off at you.
In short my two questions… (Sorry sometimes I give too much info)
Which glue to use for fusing PLA in high vibration and stress situations?
Which filament would be best to print a prop and shroud in?