bronze,aluminum and fresh water

[rolmops]

Hello.
I just purchased a bronze thru hull transducer and reading through the manual,it said not to use this on metal boats. It just so happens that my boat is aluminum,but it is kept on a trailer and only used in freshwater at a frequency of once every two or three weeks maximum.
Should I still have to worry about electrolysis(galvanic corrosion) or is it negligible in my case?
Thank you,Cornelis.

 

[Scott Danforth]

Use a thin strip of uhmw pe tape (mcmaster carr) between the brass and your hull. Seal the edges with 5200. Just need to isolate the two metals electrically

 

[dingbat]

Your boat isn't aluminum, it's an aluminum alloy.
To make matters worst, your putting a potential on the transducer.
If it where me, I'd return it and get the plastic version. Airman 319

 

[dingbat]

Verdigris (the green patina on copper alloys) is aggressive towards aluminum alloys. It turns into tiny particles of copper when in contact with an aluminum alloy. The particles in turn cause local pitting corrosion in the aluminum. Painting the area around the transducer would help but that leaves you at the mercy of a coat of paint between you and a catastrophic hull failure.