paint bubble

[Clint06]

I noticed a bubble in the paintwork around the bung of my live bait tank the other day. The bubble was full of salt from water getting under the edge of the paint and i have seen how bad this can get if nothing is done.
Has anyone got any tips on the best way to clean the salt out and reseal the paint?

[gunna]

I have similar in a couple spots in my boat and I have been told by a number of people to just leave it. They claim that exposing it to air can result in a lot more problems ??

[dnej]

Is this on an aluminium boat,or rather is the tank aluminium?
Probably find that the bung is of dis similar metal.
If so, you need to use a product, to separate the metals.Duralac is good.
In my case,I use Lanolin grease,between the joints.
Scrape off the paint,and smear on some grease,and no further problems.
David

[Wear the fox hat]

Clint06,
That's electrolysis matey. Don't leave it or it will just get worse. Take out the bung fitting, clean up the transom with a wire brush, the little ones you can put in a drill are great, but don't go too hard at it. Clean exposed aluminium with diluted hydrocloric acid & then paint with an etch primer & then a quality top coat. Consider replacing bung fitting with a palstic one & use duralac between any metal to metal fittings & fasteners. Did all this sort of stuff to my boat 3 years ago & all is still good.

WTFH

[Bin455]

What is the correct way to use Duralac??? Do you put it in the hole before using pop rivets & screws etc???

[Roughasguts]

My self personally, Wouldn't use a wire brush, your going to impregnate the ally with yet another metal. Wouldn't use hydrocloric acid, that's a lovely ally disolver.

So sand blast, glass paper or polish off, use acetone or thiners, even degreaser to clean.

The rest of the advise is fine.

[Wear the fox hat]

Bin45,
Just dip the end of the rivet in the duralac & maybe twist the rivet a little bit as you put it in the hole, this will give a good coating. With self tapping screws, just tap the hole with the screw, take it out, add duralac to the thread & screw it back in.
The idea of the diluted hydrocloric acid is to clean the surface properly before painting. Don't wash the acid off, just let it dry & then paint with your etch primer. I only did this after advice from a friend that owns a paint shop, & another friend that owns a welding business which involves aluminium fabrication.
A wire brush won't impregnate the aluminium with a foreign alloy that will cause elctrolysis. Degreaser or equivalent won't work, as it leaves residue in the pitting of the aluminium & then the primer won't stick.
There's always someone that doubts what I write when I comment on electrolysis, duralac, how to fix it etc, but as I stated, I did all this sort of stuff to my boat 3 years ago & all is still good. I've seen boats that are 12 months old & riddled with electrolysis, so 3 years on & still good after repairs should be enough proof in the pudding. Roughasguts, no offence, but I think you're a bit off the mark with your ideas.

WTFH

[Roughasguts]

WTFH, yes everyone is entitled there there own ideas or conclusions, that's what these forums are for.
As for being of the mark, you may be right, but I said for me personally I wouldn't do it.
And even after your explanation, for which your entitled to, me personally I still wouldn't do it. If others concur with your method then maybe your right.
But I do know if your battery leaks all over the floor of your tinnie, then you open it up for more corosion, pitting, flaking, and if un checked several holes.

But all said and done I have a glass boat, so really I took care of all my electrolysis issues when I bought it 7 years ago, not saying it won't have other issues.

No offence taken, Cheers.

[Roughasguts]

WTFH, there maybe some merit in your idea, I know rust converters work on the same acid principle and covert the steel and rust in to some other form which I forgot the actual composition, so as to prevent further rusting.
(all the same that doesn't work that great)

As to it working on alloy, I don't know I feel it will do damage as even mild citric acids (fruit juices) can not be stored in aluminium containers. (why is that)

But there are many ways to skin a cat.
I would just like more proof that one patch done 3 years ago, is sufficient evidence that your method works.
(maybe with out the acid wash the paint still would have stuck and I think it would)

But please fill in some details regarding diluted hydrocloric acid what ratio 50/50 is still way to strong, and some safety warning about the product it's readily available but if you breath in it's fumes just by pouring it, you will burn out your throat and lungs. The stuff is bloody dangerous to eyes, skin, and lungs, just be aware of that, and pass that information on.

Cheers.

[finga]

Save the arguements and bead blast the corrosion if possible, blow off dust, etch prime, prime then quality top coat.
Use plastic bungs and duralac when the paint is properly cured.
If your carefull you can use masking tape to limit the area of blasting to just the corroded bits and you may be able to get away with using a brush to touch up the paint.

[Wear the fox hat]

Thanks Finga, another good idea. Roughasguts & I aren't arguing from what I'm reading, just discussing our reckonings as far as I can see.
Roughasguts, the acid is only about 20-30% of the mix, so it is only light. I've fixed the bung holes plus another 6 or more other areas on my boat where electrolysis was starting & all is still good, so it's not just in one spot that was fixed. My friend that owns the paint shop actually painted a 5m aluminium cuddy cab in this fashion before I did my repairs & it is still like the day he painted it.

WTFH

[Roughasguts]

Thanks WTFH, Now a whole boat painted in that fashion sheds a bit more light on the success of your method.
Nah finga, were not arguing the point just openly discussing the merits of an approach I have never heard of before.

Honestly now if i had anything in ally, I would give it a go on a small section as a test piece.

[Bin455]

WTFH, Just wondering how old you boat was when you started getting the electrolosis in it?? The reason I ask is I have just got a new Alloy boat and and am wondering if there is anything you would recomend I do to it or look for to stop electlolosis occouring.....I mounted a compas today on the sideconsole and used duralac wish the screws.....But I am wondering if its worth doing all the screws that are already in place...

Thanks
Bin455

[NAGG]

Gee .... I hope poly owners dont see this NAGG

[Wear the fox hat]

Bin455,
My boat was 10 years old when I got it, thus the necessary repairs.
If I was in your shoes, I would do everything with duralac now to prevent electrolysis later. Another point is that you won't get screws & nuts & bolts off without snapping them once it sets in even a little bit. Also remember to wash your boat with detergent to neutralise the salt or spray with Saltex. Detergent is cheaper, just mix it up up a bit lighter than you would when you do the dishes. (if you do the dishes)

NAGG,
Are poly boats still made with that ripple effect in the hull that so that your motor is working it's ring off all the time trying to push the boat through the water??? Har har!
(gotta say har har in case my smilies don't work)