Black wake tower corrosion - 2014 242

[Pointblank]

I am curious to see if anyone else with a black aluminum wake tower has experienced this level of corrosion. This is the factory-installed DiamondBack wake tower on a 2014 Yamaha 242 Limited S. To me, it seems excessive on a boat that's been used exclusively in freshwater and under cover its whole life.

From the little bit of research I've done, it appears the underlying cause is an interaction between dissimilar metals--stainless steel bimini brackets in this case and the aluminum tower. Is that correct?

Any recommendation on how to prevent further deterioration, aside from re- powdercoating or painting? Is it mostly cosmetic or cause for concern down the line?

 

[tdonoughue]

Ew. That just doesn't look good.

Don't have an answer as to whether that is galvanic corrosion or not. But if the tower is aluminum and the screws stainless, that is certainly possible. See Stainless Steel & Aluminum: Why You Shouldn't Use Them Together and Proper Precautions To Take If You Do | Albany County Fasteners And you are in Houston, where the humidity is high, making such corrosion more likely.

Regardless, I think you are needing to take that fitting off and strip the powder coat to find out the real story there. At any rate you seem to have some sort of corrosion going on there and ultimately that fitting is going to pull loose on its own. It is simply a matter of whether it comes off at your time (when you unscrew it) or at its time (when you are flying down the water and it lets loose).

Were it me, I would consider pulling off the fitting, overdrilling the screw hole, and putting a stainless band clamp (a solid one--not the slotted kind) or two around the tower. Then screw the fitting into the band clamp (perhaps with some silicone caulk on the screw). That may separate the metals and let the bands hold onto the uncorroded part of the tower.