# saltwater and alluminum corrosion



## answer3 (Jan 30, 2016)

I bought a 14ft aluminum boat last winter and thought to use it mainly for freshwater fishing, but now that I tasted inshore saltwater fishing I am addicted and use it ~90% in saltwater (can't resist catching and eating bluefish, black sea bass, fluke and bluecrabs  ). I already added a front deck and a plywood floor with foam underneath and was on the way to attach the livewell I just made when I realized that a lot of what looks like salt buildups (or corrosion?) accumulated under the floor and on spots with unpainted aluminum. After each trip I washed the outside of the boat + trailer with a garden hose and flush the outboard with freshwater, but I didn't do anything inside the boat. I guess I should have... 
How do you guys clean the inside of your aluminum boat after a saltwater trip? is it enough to only wash it with fresh water using a garden hose? 
My original plan was to add the livewell and some storage compartments on each side (a little bit like a bass boat). But if I do that I won't be able to remove everything to give it a good clean every once in a while. I was thinking to maybe seal the sides of the floor, front deck and storage compartments with silicone or 5200 so everything is watertight and wash the whole inside of the boat with the garden hose after every trip but I am not sure if it will be watertight enough.
anyone of you faced a similar issue? what would you recommend?

a few pictures to show you what I am talking about:


This is below the floor and front bench




this is on the side of the boat where the middle bench seat was attached




This is the front of the bow plate. I removed some of the salt deposits (corrosion?) with my finger




gunwale


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## Fishfreek (Jan 30, 2016)

I may be a little over kill but I rinse mine using a small electric pressure washer. First I use the soap attachment and shoot some Purple Stuff then rinse with fresh water. It only takes 10 minutes and I also give rods reels and cooler a shot at the same time. If I am away from home I find a self servise car wash as soon I possible and spend a couple dollars.


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## answer3 (Jan 30, 2016)

do you have any floor or storage compartments in the boat? If so do you remove them before washing inside the boat?


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## Fishfreek (Jan 30, 2016)

No floor compartments but on my previous boat I used a product called Sharkhide they also have a cleaner that helps remove the spots and spekes of corrosion.


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## mbweimar (Jan 31, 2016)

My front storage looked like that on the inside after a couple years. Like fishfreek, I rinse mine down IMMEDIATELY after saltwater use, even if I come in at 4am. The longer you wait, the worse it gets.


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## surfman (Feb 3, 2016)

You can't make it water tight, no matter how hard you try, you need to make it so that you can rinse it good. I have a 1448 and I added a plywood floor, I did not put any foam under the floor and I don't recommend it for salt water, plus I really don't think it is necessary or helps deaden the sound that much. You need to be able to let the fresh rinse water run under the floor. Be sure to totally seal your wood on all sides, I used epoxy. You may want to strip it out and clean it up using a pressure washer and then some phosphoric acid cleaner, then paint it with a good quality primer and paint.


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## answer3 (Feb 4, 2016)

thanks for the info! any good phosphoric acid cleaner and primer/paint you would recommend?


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## mbweimar (Feb 4, 2016)

Bar Keeper's friend is what I used to clean up my hull before sending it off to be welded. It's similar to Comet in consistency, very fine abrasive powder. Mix with a few drops of water, and it'll rub it in with a sponge. You'll swear its a new boat!


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## mbweimar (Feb 4, 2016)

Oh yeah, did I mention it's CHEAP?


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## DaleH (Feb 4, 2016)

surfman said:


> You can't make it water tight, no matter how hard you try, you need to make it so that you can rinse it good.


Once you get it cleaned up, I *highly recommend a good coating of protective wax* be applied, like that of Woody Wax or Rupp's (make of outriggers) aluminum protectant.


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## HeavyHook (Feb 4, 2016)

mbweimar said:


> Bar Keeper's friend is what I used to clean up my hull before sending it off to be welded. It's similar to Comet in consistency, very fine abrasive powder. Mix with a few drops of water, and it'll rub it in with a sponge. You'll swear its a new boat!



Awesome idea - I will keep that in the files. I only go in freshwater but I am going to be trying some flats fishing and did not know about bar keepers friend.


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## mbweimar (Feb 4, 2016)

It's sort of an all purpose metal cleaner. But works wonders on my kitchen sink, my stainless exhaust tips, bare aluminum on my boat, etc. You can find it just about anywhere. One word of caution I forgot to mention, it can be messy. Rinse well, and maybe wipe down with a damp towel afterwards, otherwise the white residue will be all over.


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## DaleH (Feb 4, 2016)

mbweimar said:


> One word of caution I forgot to mention, it can be messy. Rinse well, and maybe wipe down with a damp towel afterwards, otherwise the white residue will be all over.


FYI, they make a* liquid version* too that I like better for use on a boat. It comes in a plastic bottle too, versus one of those cardboard-bound cans. I agree, it is a superior cleaner for all-around boat use! 

Where I know some do keep an amount of the powder on hand was for deep-cleaning blood spots of the decks on frp boats. We'd mix the powder with a small amount of water or 10% bleach solution, to make a paste, and would leave it on the tough stains. Just don't leave it there too long, as it could bleach the substrate to a lighter color than the surrounding deck. _Now go ahead ... ask me how I'd know that ... :?: ?_


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## answer3 (Feb 4, 2016)

Can I use this Bar Keeper's friend on the painted parts of the hull or is it going to strip the paint a bit? I think overall the paint is in good shape, there are just some spots like under the seats that are not painted so the salt did some damages there. 
I will definitely put some wax after I repaint everything. 
Any good paint you would recommend? also can I paint over the existing paint inside the boat so I have something homogeneous? hopefully I don't have to strip the paint and put a new coat everywhere...


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## DaleH (Feb 4, 2016)

answer3 said:


> Can I use this Bar Keeper's friend on the painted parts of the hull or is it going to strip the paint a bit?


Strip it? No ...

Dull it? Yes ...

I wouldn't use it on any nicely finished surface. You will even ruin the native patina on aluminum or bright steel 'treadplate' if/when using the powdered stuff.


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## surfman (Feb 5, 2016)

You can get the phosphoric acid cleaner at the hardware store in the paint dept. I don't have a recommendation of paint. I actually didn't paint mine but I like the wax idea.


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## answer3 (Feb 5, 2016)

from what I read about the wax looks like it will last a few months so I understand that paint would be for permanent protection and wax for extra protection and easier cleanup of the surface
How often do you think I should apply the wax? once before the season and one in the middle of the season?


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## answer3 (Feb 18, 2016)

Fishfreek said:


> I may be a little over kill but I rinse mine using a small electric pressure washer. First I use the soap attachment and shoot some Purple Stuff then rinse with fresh water. It only takes 10 minutes and I also give rods reels and cooler a shot at the same time. If I am away from home I find a self servise car wash as soon I possible and spend a couple dollars.



what is the power of your pressure washer? I found a 1450 PSI one for ~$80 on amazon. Is it ok or is it too powerful and risks damaging the paint?


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## Fishfreek (Feb 18, 2016)

That's what mine is too. You should be fine.


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## answer3 (Feb 19, 2016)

thanks! I just placed the order, this weekend the boat is going to look like new 
I got a bottle of simple green pro HD with it, is it the detergent you use or do you have something else?


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## answer3 (Feb 25, 2016)

update: the pressure washer cleanup worked pretty good. all the salt buildups are gone! 

However, I noticed that the paint around several rivets was lifted making some kind of bubbles. I wire brushed some of these zones and the paint came off easily. Is it a sign of galvanic corrosion caused by salt buildups on the rivets? (don't have a picture of that here, will take one tonight and post it)

Also, the parts with bare aluminum that were behind the center seat I removed still show signs of corrosion even after pressure washer cleanup. I tried to wire brush the zone, sand it with 220 grit sandpaper, even polish with a buffing wheel in some spots to give it a try. This removed the white particles on the aluminum but there are still some darker spots below that stay in the aluminum no matter how hard I try to remove them. I guess the corrosion went deep... You can see that on the picture below:



From what I read here in the site and your comments, I have to stop the corrosion with chemical treatment then apply primer/paint then wax. Hopefully it is not too late! What would be a good chemical treatment to remove corrosion? Phosphoric acid, white vinegar, bar keeper's friend? Also, should I use something like Rust Encapsulator or POR 15 to help contain corrosion / prevent it from spreading?


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## answer3 (Feb 25, 2016)

Here are the bubbles around the painted riverts


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## answer3 (Feb 25, 2016)

And found this slimy stuff coming from under the ribs in many places under the boat, after I power washed it. Any idea what that is?


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## answer3 (Feb 26, 2016)

nobody?


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## Fishfreek (Feb 26, 2016)

After treating with something like OSPHO you can't go wrong with PORT 15


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## answer3 (Feb 27, 2016)

thanks! after power wash, I cleaned with bar keeper's friend then powerwashed and degreased with simple green. next step will be OSPHO then paint. I will post pictures when it is done


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## answer3 (Mar 9, 2016)

looks like por15 is to use only on bare metal, not on previously painted surfaces. Because the paint inside the boat is in good shape for 90% of the whole surface, I don't want to strip it and add por15 on top of it, it would be way too long. plus the price of this stuff is crazy... doing the hole inside of the boat with it is going to kill my budget :shock: 

I already started treatment with ospho, looks pretty effective. I am going to spray OSPHO to make a small layer on the bare aluminum parts that have corrosion so it makes the impermeable coat that protects from further corrosion. But then what primer do I add that would stick to both ospho and the previous paint? Would Rustoleum latex aluminum primer work in this case? it seems good for adding over previous paints but not sure if it will stick to ospho since they say it is best to use oil based paint over it. epoxy 1k primer also seems pretty good to add on previous paint, but again, not sure if it will stick to the ospho... I am lost... please help me guys!!


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## CedarRiverScooter (Mar 9, 2016)

I would call or email OSPHO company & get their recommendation on the best paint to use.


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## uncndl1 (Mar 10, 2016)

This Primer tutorial from member Johnny should help you sort out some questions:
https://www.tinboats.net/primer-and-paint-basics/


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## answer3 (Mar 10, 2016)

uncndl1 said:


> This Primer tutorial from member Johnny should help you sort out some questions:
> https://www.tinboats.net/primer-and-paint-basics/



This is one of the things I was looking at and made me think about latex aluminum primer or epoxy 1k, but the OSPHO is messing up all this plan since the manufacturer says it is best with oil based primer instead of latex or epoxy primers... I don't want to have the paint lift up or detach after a few months because of the OSPHO coat I put underneath.


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## uncndl1 (Mar 10, 2016)

Tractor Supply carries an oil based primer for $20/gallon, 
Rustoleum must also.
Also could check with paint company you're looking at 

Sent from my SCH-I545 using Tapatalk


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## answer3 (Mar 11, 2016)

Thanks. I found the oil based primer #7780 from rustoleum that would be compatible with OSPHO, but it says in the instructions that "smooth, hard, or glossy finishes should be scarified by sanding to create a surface profile" which I think is the case for the inside paint in my boat. Is this the case with any primer whatsoever or are there different primers that stick without needing to sand the old paint?


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## CedarRiverScooter (Mar 11, 2016)

I worked with a paint engineer who said that there is almost never an adhesion issue when old substrate is sanded. Sometimes you can get away without sanding, but who knows when those conditions are just right?


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## answer3 (Mar 12, 2016)

thanks for the reply, let's do some sanding


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