Broken thru hull

[Yooper]

I had all four anodes replaced two months ago when I had the bottom painted. These pictures are after I cleaned the growth off. Didn’t seem to find much corrosion on the bracket or lower unit.

 

[DennisG01]

You mentioned earlier that the anodes were "about gone" and that your mechanic said "they are bad". Are you sure you guys were looking at your boat and not someone else's? Those anodes are exactly what I would expect from 3 weeks in the drink - still in very good condition. I would take a wire brush to the bracket anode, though.

 

[Yooper]

What do you think could have caused all the growth in the previous pictures? Some sort stray current or galvanic corrosion. Which brings me back to my original post. What could have caused the thru hull to weaken.?

 

[DennisG01]

What do you think could have caused all the growth in the previous pictures? Some sort stray current or galvanic corrosion. Which brings me back to my original post. What could have caused the thru hull to weaken.?

Your engine isn't anti-fouled, as previously mentioned. Are there any other similar rigs to yours in your marina (w/o anti-foul) and how have they faired? I don't think you mentioned where you are, but if you're in active water, I don't think that growth is abnormal, by any means.

Thru-hull weakening... my most logical assumption would still be what I first mentioned.

 

[seasick]

A galvanic issue is not going to cause growth. Like I proposed earlier, the lower motor bracket and tilt assembly appear to be coated with something based on the rough surface appearance. I wonder if whatever it is, barnacles like it.
The broken thru hull is probably not galvanic related unless you also see that the outside flange is eaten away. It may just be a bad casting from day one and it finally broke.

In my experience, anodes that get eaten up quickly have been exposed to stray currents either from your boats shore power or very often stray currents in the water where you are slipped. Those can be a real pain to find ( and don't jump in the water to look for them!)