[fishn_n_tx]

I have a new 1760 aluminum boat I put a 1971 Evinrude 50 on. I accidentally left the key on overnight. It was on the trailer out of the water, but the next morning there was some corrosion spots on the lower unit and a few on the rear of the transom. All wiring is grounded strait to the batteries(not the hull) except for the Evinrude motor. I plan on installing a battery cut-off switch so the only time the motor will have power to it is when it is running. Is the corrosion something I should worry about? I also plan on adding a few sacrificial anodes to the lower unit. Is it possible for the corrosion to eat thru a .100 gauge hull or is it mostly cosmetic damage?

[myalibi]

If you are using your boat in the salt water you will also need anodes on the boat itself. I would also ground your engine to your starting battery. That should take care of the problem. I would think that it would take a long time to eat through your hull. One of the beautiful things about aluminum is that it is pretty easy to clean up and look new again.