I hope you don't mind if I throw my two-cents in? And just so you know, my opinion these days comes from experience with salty dogs here in Florida.
Here's the thing... salt and aluminum don't do well together. End of story.
I don't care how well you think you clean your boat off, salt and salt water will go places you can never rinse it out.
West Marine sells a product called Salt Away which when used can chemically neutralize the salt that it can get to and follow into places you can not rinse out. But even that is not a solution to salt on aluminum.
I recently scrapped a boat I really loved made by AlumaCraft because of salt water damage to the hull.
It was another one of those boats given to me I was thankful for until I spent hundreds of dollars on it only to find out I had wasted my money on it and then regretted ever taking the salty dog.
The boat suffered from years of salt water getting into places the previous owner could never rinse out, and he used pressure treated skids under the boat which also corroded the hull.
And these days it pisses me off to no end that aluminum boat manufacturers seem to always try and find a way to reduce the amount of metal in a boat as the hulls get thinner and thinner to the useless point.
So let me just say it before showing you some photos of what salt does to a boat that if you want to put your aluminum boat into salt water, then just beat the hell out of it and use it until you can use it no more. Sinking money into a salty dog is a waste of time in my opinion. Nothing can save the aluminum if that is what you choose to do with it. Beat it up and get another one and beat it up and get another one.
The boat I was given was a 1983 AlumaCraft T-14XL-20. Since it was free I decided to cut the transom down to fit my Yamaha 25 on it. I was not about to sell that motor and try and buy a long shaft for just this boat. No way. So I tore into the transom and this is what I found:
Just look at all those white salt crystal around the drain holes for the transom tray drains! Leaked right into the wood. Was never sealed from the factory. So over 30 years, the salt water would leak inside and then dry out leaving behind accumulating salt crystals that ate up the super thin aluminum hull like it was in acid.
Look how thick all that accumulated salt is! I measured some with a tape measure as thick as a 1/4 inch! And now we are looking at what was in between the wood and the hull where the majority of the salt was found:
The above image is the transom hull as soon as I pulled the wood away from it this is what was there. Ugly!
If light can shine through the transom hull, then you know water was too- salt water that is. Now I know why the boat was free!
Do you think paint will save the hull from salt water corrosion? Did not help this boat.
This is what it looked like with the transom knee removed. More salt water corrosion rinsing will not help with. Salt stays!
I was going to leave those corner handles on, but had to take them off for the transom repair. Most salt underneath. More corrosion. Look at all those holes circled eaten right through the hull. The previous owner just shoved caulk in the holes as his solution.
Starting to see my point? Nothing you can do if you put that boat in salt. Just a matter of time. Beat it up and get another one...
Cast aluminum eaten up! And in a place you think you can rinse!
This is where the boat sat on skids. Salt water corrosion plus pressure treated wood chemicals too!
I could go on all night, but the evidence is clear. Salt is no good for aluminum. Salt gets in and stays. It is just a matter of time.
That's my story and I'm sticking to it.
I scrapped the entire boat for about $100.00 worth of aluminum.
