How to clean corroded Through-hulls ?

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Originally Posted by 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

for safe cleaning use oxalic acid. hempel gelcoat cleaner is easy to buy in italy

https://www.hempelyacht.com/en-gb/ho...leaning-powder

[AleCiotti]

Originally Posted by more

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

Yes that's basically it lol

[AleCiotti]

Originally Posted by more

for safe cleaning use oxalic acid. hempel gelcoat cleaner is easy to buy in italy

https://www.hempelyacht.com/en-gb/ho...leaning-powder

Ok, and what about diluted vinegar? as other people mentioned it on the thread?
Thanks!

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Originally Posted by AleCiotti

Ok, and what about diluted vinegar? as other people mentioned it on the thread?
Thanks!

no. for brass,bronze,boat gel coat,big factory polish brass bronz use oxalic acid. always must have on boat 1 kg hempel gelcoat cleaner.how you clean before polish your boat.

if you can remove brass part overnight is possible safe clean with citrus acid.
hempel gelcoat cleaner is +- 15€ 1 kg

citrus acid C6H8O7 or CH2COOH-C(OH)COOH-CH2COOH is so close to oxalic acid C₂H₂O₄

but oxalic acid is simply beter,special if you have cloged toilet pipe only oxalic acid safe disolve calcium salt water deposit in pipe,or in human body. only safe oxalic acid disolve stone in kidney for example.
you dont know chemical composition of your valve, idont know .safe solution oxalic acid.

[ve0hak]

The green is corrosion, but the white looks like salt crystals. This suggests seawater seeping in probably through the threads.

[Bluechart]

Beneteau?

Any attempt to remove/replace hoses could easily break the through hulls off. CAUTION

If you must, gently wipe with a cloth, vacuum up debris, carefully replace broken hose clamp, do not attempt to cut or remove the hoses, I’m sure you have lots of pink in the metal, you just don’t see it.

(I replaced all my through hulls and valves with truedesign , and all the hoses and clamps)

[Nicholson58]

Originally Posted by 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

If you can remove and disassemble then toss the BRONZE parts in muriatic acid. Quick in and out, rinse. Reassemble with grease and new seals if appropriate. They will look like new and operate easily.

Brass should not be used (yellow) but only ‘marine bronze’ which shows copper-like coloring in the cut threads. Groco parts are bronze. Home Depot yellow brass will quickly corrode. Many of the good bronze valves have an NPT port plug between the ball seats. Remove it and substitute a SS grease Zerk to mak lubrication forever easy.

[Goodxcharly]

A brass wire brass, softer though Any type would work probably work.

[Peter Hansell]

Piggybacking on the use of a brass wire brush, I find success using brass wool and WD-40; I suspect, any type of penetrating oil would suffice.

Start with a rough grade #3 or #2, and work down to a finer grade like #000.

[Cpt Mark]

Going back to hose clamps. AWAB and the like I stopped using. They are barely ok IMHO. I use T-clamps now. Way more expensive but the superior quality makes them very worthwhile.

[sinnerman]

I have used a mixture of lemon juice and salt.

Make a wet paste, apply it to to green areas and wait.

Wipe it off , rinse with fresh water.

Repeat if necessary.

It is a dirty job but it works.

I assume vinegar / vinegar and salt / vinegar and baking soda would also work..

my two cents

cheers

[DreamWeaver III]

They might look not dezincified but on the inside they might tell a different story - mine looked similar to yours but crumbled

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Originally Posted by sinnerman

I assume / vinegar and baking soda would also work..

my two cents

cheers

when you so clever mix in home vinegar and baking soda and tell as what you recive. do you in elementary school have chemistry class. i have and always have grade 2( this is little over return next year 5 is best)
mixing vinegar and baking soda produce co2. rest in process is impurity vinegar/baking soda and H2O

baking soda simply neutralize vinegar acid.

like i say oxalic synthetic better from natural,this use in industry for cleaning brass ,for neutralising simply any H2O .normaly adding more complex chemical in oxalic acid help faster cleaning. sulphamidic acid 1-2%propan-2-ol 1%