The lower unit that hold the props on my Brand New Minn Kota Edge started spinning oddly on a recent fishing trip.  Come to find out after investigating that the threaded composite rod that holds lower unit came loose.  After trying to apply some lock tite on I noticed that the threads just disentingrated as I was tightening it back.  I noticed that the adhesive said not for plastics.  Not sure if this had anything to do with the stripping of the threads?? Anyway, had to order another rod and want to make sure the adhesive is correct before I thread it back on.  Minn Kota reps are clueless and gave me no advice on what to use.  They keep telling me to take it to an authorized dealer.  The nearest dealer is 5 hours away so that is out of the question. Any suggestions on what adhesive to use?

3m 5200. waterproof and permanent. 

The best thread lock for plastic/composites is medium SuperGlue, not the real thin stuff. As you have learned the hard way, NEVER apply Loctite to plastics/composites.

Never tried 5200 but don't see why it wouldn't work also, probably even better, but as mentioned, it will be permanent, where the super glue you do stand a chance at getting it loose again. A little heat might let you take the 5200 apart again.

4200. Not as permanent as 5200, just in case you want to take it apart again.

Send it to minn kota. It seems to me that any adhesive you try to use will fail. IMO it is best to replace it. MK has great customer service.