Just get a dexter axle.
Iíve built and repaired a lot of raft trailers. If youíre going to build one just get the dexter axle. Iíve built a couple with the 3500lb axle. They bounce around like crazy unless youíre going loaded with multiple multi day trip boats. Realistically a 2000 lb dexter axle is perfect for one or two loaded boats or up to a triple stack of cats running day trips. As far as bearing buddies, they arenít effective. EZ lube spindles as supplied from dexter axle are functionally amazing. They force lubricant through the rear bearing, if youíre not impatient and slowly pump the grease in, you can go years without servicing. Provided you donít submerge the axle hubs. I replaced my bearings last year after 15000 miles. The bearings were not bad, but were cheap to replace as a precaution. There is a reason almost every major trailer manufacturer uses dexter axles exclusively.