White powdery substance on lower unit after fishing

[muskie00]

Something happened to my lower unit last night while fishing. I got home and there was white gritty stuff on my lower unit and on the back of my boat. It looks like calcium or hard white powder. This was not there before I went fishing. One more thing, it was the first time using this motor: Johnson 20 hp 1969 elec, start. I am stumped as to what it is or why this happened. Please see photos.

Muskie00

 

[kodibass]

Re: White powdery substance on lower unit after fishing

Not a clue, but if you caught any fish don't eat'um

 

[lindy46]

Re: White powdery substance on lower unit after fishing

I've seen that happen on boats/motors left in the water for long periods of time, but not one trip out. You fishing in the Great Salt Lake?

 

[the machinist]

Re: White powdery substance on lower unit after fishing

From the condition of the underwater parts of the hull & what I see on the motor it appears to be salt reaction to bare aluminum. But this would normally not occur overnight. Do a slight taste test, if it tastes like salt, that is your situation. The solution would be clean the motor good & repaint it.

 

[muskie00]

Re: White powdery substance on lower unit after fishing

Well I am stumped.. We were fishing in (fresh water) Pecatonica River in northern Illinois.
I have fished this river all my life and I have never seen this before.
This is the first time I used an electric start motor.
Could it be from the battery? maybe it is sending a charge through the aluminum boat and attracting the white "lime like" powder??
The powder is mainly adhering to bare spot where the paint is scraped of on motor.
Sound crazy but I am totally stumped.
One more thing... the river is lower than I have ever seen before.
And yes we are catching nice flathead catfish.... see attached photo.
I always catch and release!