Boat Corrosion??

[bstarling]

I recently bought a 14 foot aluminum jon boat that needed to have the bottom cleaned of marine fouling. After getting down to the hull I realized that there was a very significant amount of corrosion. The boat is a 2005 and had been kept in the water for a while, but I've had a lot of aluminum boats that have stayed in the water and grown huge amounts of fouling on their bottoms. This is the first time I've seen this. I googled "Alumicraft corrosion" and found out that this seems to be too common on the 14 foot 2005 models. What's the deal? Has anyone had or know of anyone with a similar problem? I've attached some photos.

http://i97.photobucket.com/albums/l219/wbstarling/2005%20Alumicraft/Hull8.jpg

http://i97.photobucket.com/albums/l219/wbstarling/2005%20Alumicraft/Hull6.jpg
Transom with most of the rivet heads gone on mostly gone.

http://i97.photobucket.com/albums/l219/wbstarling/2005%20Alumicraft/Hull5.jpg
Close up on transom

http://i97.photobucket.com/albums/l219/wbstarling/2005%20Alumicraft/Hull11.jpg
Bottom about 4 feet up from transom

http://i97.photobucket.com/albums/l219/wbstarling/2005%20Alumicraft/Hull12.jpg
Close up of above photo

http://i97.photobucket.com/albums/l219/wbstarling/2005%20Alumicraft/Hull1.jpg
Most of the bottom rivets look like this with corrosion all the way around them.

Comments appreciated.

Bill:fishing:

[bmcox86]

crappy rivets?

[bstarling]

I was thinking that. A friend of mine had a Duracraft many years ago that had crappy rivets. He kept .22 cal. casings in his tool box to plug them when he was out. He probably replaced most of the bottom rivets on that boat in the time he had it. His boat didn't get that sort of corrosion though. Something is crappy for sure.

Bill:fishing:

[kapoc]

could be electrolisys..... looks like their might have been a poorly grounded power source near it to speed the process along.

[eaglesfanguy]

Yikes... my jon boat is an 81.. with mad time on the water... never anything like that...only problems i had was going to fast in rough seas and splitting welds,, but i had access to an aluminum tig welder and fixed it up.. but never corrosion like that.... looks like some pot metal not true aluminum..

[AL SEARS]

Few years back I had to sand Blast a fleet of rental boats such as yours, they was eaten up wth pin holes every where transon and bottom were the worse,found out later it was way the paint was put on and wrong type paint was cause of corrosion