Stern corrosion issue, need help

[ctangler]

I have a 1993 16' V16 Aluminum Bass Tracker. On the exterior of the stern wall I see corrosion pits eating through the aluminum. I don't see this anywhere else on the boat, all of the other walls both interior and exterior are fine. There are about a dozen spots scattered around the stern wall, all above the water line. Many of these corrosion pits are about the size of a medium phillips head screw driver tip and I can see the wood of the stern backing in the holes. I took a multimeter set to check continuity and tested various points on the hull and motor and everything is common. Im not really sure whats going on but I need to fix it before I get a leak. Any ideas whats causing it and how to repair the damaged spots ?

 

[WillyBWright]

Re: Stern corrosion issue, need help

Saltwater? Bare aluminum in saltwater is like an Alka-Seltzer tablet.

Two words...Battery Switch!

Or one word...Trailer.

 

[tashasdaddy]

Re: Stern corrosion issue, need help

if you can see the wood, you already have a leak. the wood will be wet.

 

[WillyBWright]

Re: Stern corrosion issue, need help

Look for rot in the wood in the transom, JB weld will patch the holes and fill the pits.

 

[ctangler]

Re: Stern corrosion issue, need help

The boat is painted, not bare aluminum. There is no leak yet, I ran the boat last weekend for two hours and had no water in the bilge. It was used on occasion is saltwater years ago by my dad, the last 6 or 7 years have been fresh water only.

Do you believe the corrosion is caused by the battery being hooked up ? What is JB weld and how would it be used ? Thanks.

 

[tashasdaddy]

Re: Stern corrosion issue, need help

if there is a hole in the transom there is a leak, leaking into the wood, and the wood is absorbing it. JB weld is a 2 part epoxy. that you mix and apply with a popsicle stick.

http://jbweld.net/products/marine.php

 

[ctangler]

Re: Stern corrosion issue, need help

Any ideas on what might be causing the corrosion ?