How to clean corroded Through-hulls ?

[AleCiotti]

Hi guys my boat has corroded through-hulls made of Brass, the corrosion is mainly of white and green colour and I haven't seen pink yet (dezincification) so even though they look terrible, I'm not panicking yet.

How do I go about cleaning the cosmetic corrosion? I've heard many people say water and vinegar / baking soda / lime.. but I'm not really sure about it.

Thanks

[AleCiotti]

I will be changing most-all the trough hulls with non-metallic (trudesign) ones in less than a month.

[Orion Jim]

Originally Posted by AleCiotti

I will be changing most-all the trough hulls with non-metallic (trudesign) ones in less than a month.

Less than a month…I’d avert my eyes till the replacements are installed.

[Statistical]

If they can be opened and closed and you are replacing them soon I wouldn't do anything until you replace them.

[paul.devalier]

Ok, but what if OP had said a year.
Following...

[Statistical]

Originally Posted by paul.devalier

Ok, but what if OP had said a year.
Following...

The best way would be to remove the seacocks (OP said thruhull but photos are of seacocks) when on the hard, use a brush to remove as much surface corrosion as possible and then put them in a bucket of vinegar diluted to 50/50 for a couple hours (or overnight). Rinse thoroughly. Reinstall.

If you can't or won't do that then ketchup works. It has vinegar and the consistency means you can paint it on, wait and then wipe it off.

[CarlF]

I’d be much more worried about that hose and especially the rusted hose clamps.

I can’t tell from the picture but is one hose clamps cutting into the hose cover and the other not clamping on the seacock nipple?

If the hose clamp is cutting into the hose replace the hose now.

Also put on two new hose clamps (AWAB or other high quality 316 stainless brand). Make sure they are both clamping on the seacock nipple, not falling off the end. Clamps should be at least a clamp width back from the end of the nipple.

The hose should not have any bulges that would indicate the layers are delaminating.

When you are replacing the seacocks replace any below the waterline hose that is more than 10 years old.

Failed hoses and clamps sink many more boats than failed seacocks.

[thinwater]

Avert your eyes, don't go far, and find something else to fix. Given that situation, there are other important projects. You'll be replacing the fittings, hoses, and clamps in a month.


All kidding aside, anything that will remove heavy corrosion risks slight weakening.


But just sayin' you need a weak acid, and CLR is probably one of the best products for this. Vinegar is too slow. A small wire brush too. But you are replacing them, so leave them alone.

[thinwater]

Avert your eyes, don't go far, and find something else to fix. Given that situation, there are other important projects. You'll be replacing the fittings, hoses, and clamps in a month.


All kidding aside, anything that will remove heavy corrosion risks slight weakening.


But just sayin' you need a weak acid, and CLR is probably one of the best products for this. Vinegar is too slow. A small wire brush too. But you are replacing them, so leave them alone. They might start leaking.

[Orion Jim]

Originally Posted by paul.devalier

Ok, but what if OP had said a year.
Following...

Then the wise man would remove and replace ASAP.

[AleCiotti]

Thank everyone for the replies, sorry for the error, I'm Italian (I though seacoccks and trough-hulls meant the same thing), if it was for me I wouldn't touch that corrosion but my boat will have a safety inspection in about 2 weeks, and I can't replace the seacocks until 1 month so I need to do the best I can to make them better right now.
if I don't pass the inspection I can't go to the shipyard and I will not be able to change them =(.

A bit of a strange situation I know, but I need to do the best I can to get the boat safe.

[AleCiotti]

Originally Posted by CarlF

I’d be much more worried about that hose and especially the rusted hose clamps.

I can’t tell from the picture but is one hose clamps cutting into the hose cover and the other not clamping on the seacock nipple?

If the hose clamp is cutting into the hose replace the hose now.

Also put on two new hose clamps (AWAB or other high quality 316 stainless brand). Make sure they are both clamping on the seacock nipple, not falling off the end. Clamps should be at least a clamp width back from the end of the nipple.

The hose should not have any bulges that would indicate the layers are delaminating.

When you are replacing the seacocks replace any below the waterline hose that is more than 10 years old.

Failed hoses and clamps sink many more boats than failed seacocks.

Thanks for the advice,

If the clamp is cutting into the hose due to corrosion, can I take it off, cut the damaged part of the hose and put it back on with a new Hose clamp? or do you recommend to change the whole hose? ( if you say to change any 10+ yrs old hose than I will probably have to replace all of them when I do the trough hulls so it doesen't really matter )

[Statistical]

Originally Posted by AleCiotti

if I don't pass the inspection I can't go to the shipyard and I will not be able to change them =(.

Wait what? That is insane.

What if you had something genuinely unsafe but which can only be fixed on the hard like say torn packing box hose. Your only option is to let the boat sink instead of taking it where you can make it safe?

[more]

Originally Posted by Statistical

Wait what? That is insane.

What if you had something genuinely unsafe but which can only be fixed on the hard like say torn packing box hose. Your only option is to let the boat sink instead of taking it where you can make it safe?

simply no inspections no insurance,no insurance no shipyard end story.
inspection goverment bob
insurance private john company
shipyard private jenny company
bob don't know john,jenny and don't car who is john or jenny. for bob most important thing in world is what on lunch manu spageti or penne,with carne or tomato

[Statistical]

Originally Posted by more

simply no inspections no insurance,no insurance no shipyard end story.

Oof. Yeah that is a bad catch-22. I have always had insurance (at least liability) never really considered if you lost it and needed to get it back the challenges that could involve.