Tiny rust dots / spots on the top deck of my steel boat

[zeseb]

Hallo,
My boat is a steel hull.
I have a few rust dots or spots spread on my top deck (See pictures). How can I deal with it to control it?
Thanks.
Sebastien.

[MartinR]

They will disappear if you wash the deck with phosphoric acid. For a short while anyway...... .

Long time solution: sandblasting, priming, painting.

[El Pinguino]

That looks like Treadmaster. Rust specks are probably due to someone using a hacksaw or grinder on 'stainless' fittings... nothing to do with hull construction being steel.

[MartinR]

Originally Posted by El Pinguino

That looks like Treadmaster. Rust specks are probably due to someone using a hacksaw or grinder on 'stainless' fittings... nothing to do with hull construction being steel.

You are probably right.

[NPCampbell]

I saw on an infomercial that this problem can easily be solved by dipping the entire boat in CLR.

[S/V Alchemy]

Originally Posted by El Pinguino

That looks like Treadmaster. Rust specks are probably due to someone using a hacksaw or grinder on 'stainless' fittings... nothing to do with hull construction being steel.

Correct. Paint failure is usually more noticeable and the anti-skid is not metallic (unless you own a very big boat!). This looks like a grinder-related issue.

[mvmojo]

MaryKate On & 0ff does a good job of removing rust - mop it on with a sponge mop & rinse it off.

[s/v Jedi]

I would try the least aggressive options first. Start with wetting the deck, then sprinkling some Barkeepers Friend on, scrub, wait, scrub, rinse.

If that doesn't do the trick then I would try the On&Off but probably dilute it before getting it on the Treadmaster. You can also try Ospho (= phosphoric acid)

[jhulmer]

That is caused by steel grinding dust. I sail a lot on a steel boat I helped a friend build. We have to grind and paint rust spots every year. If we don't clean the dust up quick, we get what you have in your pictures.

As mentioned above clean with Phosphoric acid or a rust away cleaning product.


edit: for everyone else if someone is grinding on a steel boat in the yard close to you, your deck will look like that too!

[Pole]

Quite right. Thats somebody grinding close by, and you're getting some metal dust on your deck. Oxalic acid (or the namebrand stuff mentioned above) does the trick - quick and easy. Don't use it too much though, it will cause the top layer of paint to oxidise and form a powder and eventually you'll have to repaint.

Best thing with these treatments is to dilute with water, wash it on with a broom - then about 30 minutes later wash it off again with water... et voila!

Been doing it for 7 years and my ship still looks new(ish)!

[RaymondR]

Oxalic acid can be found in hardware stores as a concrete cleaner.

[Freedom45]

10:1 mix of water and phosphoric acid in a spray bottle.
Spray it on spots, looks like steel particles from grinding or drilling.

Cheers

[zeseb]

Thanks for all your suggestions, I will try and let you know. I also think it's grinding residue from other boat indeed.

[peter57]

Originally Posted by zeseb

Hallo,
My boat is a steel hull.
I have a few rust dots or spots spread on my top deck (See pictures). How can I deal with it to control it?
Thanks.
Sebastien.

Oxolic Acid, follow the instructions it will remove them easy. I use a broom adapted scotch bright and do the whole deck and wash down with a copious amount of water and then jump in the tender and wash down the top side of the hull where it pours out the scuppers.