Rust spots on the deck from grinding on a boat next to mine

[haveaday]

Hello,

While my boat was out of the water about three months ago a contractor working on the boat next to mine did some grinding on metal that covered my boat in metal fragments. Pretty quickly this metal started rusting on the deck. I did my best to get as much off as possible and was somewhat succesful. Unfortunately over time the rusting has gotten worse and I haven't been able to get much of the metal out of the deck. The shavings are in most of the flat surfaces on the boat, nonskid and smooth glass. It covers port and starboard sides from the stern to forward of the pilot house on the boat.

I have tried whinks, bar keepers friend, compound, wet sanding, etc. With agressive enough wet sanding I can get most of it out of the smooth areas but I'm worried about going too deep into the gel. In the nonskid I haven't had the same success. At this point the yard has filed an insurance claim with their carrier but I'd love to know what others have done to remedy a situation like this. I'm travelling full time on the boat so while the work was done in Gulf Shores, AL I'm now in the Bahamas and won't be able to return to the same yard. The yard was a very high quality operation and they have been very stand up in dealing with this. This was a failure of a subcontractor and one I am confident the yard will deal with.

Any information would be appreciated.
Ben

[Outlaw7]

Put straight Ospho on it, they will go away, may need to do it a couple times. Pour it in a bucket use a stiff deck brush, let it set and then rinse.

[Triumphant]

Phosphoric acid will also work and much cheaper than Ospho

[geoleo]

Originally Posted by haveaday

Hello,

While my boat was out of the water about three months ago a contractor working on the boat next to mine did some grinding on metal that covered my boat in metal fragments. Pretty quickly this metal started rusting on the deck. I did my best to get as much off as possible and was somewhat succesful. Unfortunately over time the rusting has gotten worse and I haven't been able to get much of the metal out of the deck. The shavings are in most of the flat surfaces on the boat, nonskid and smooth glass. It covers port and starboard sides from the stern to forward of the pilot house on the boat.

I have tried whinks, bar keepers friend, compound, wet sanding, etc. With agressive enough wet sanding I can get most of it out of the smooth areas but I'm worried about going too deep into the gel. In the nonskid I haven't had the same success. At this point the yard has filed an insurance claim with their carrier but I'd love to know what others have done to remedy a situation like this. I'm travelling full time on the boat so while the work was done in Gulf Shores, AL I'm now in the Bahamas and won't be able to return to the same yard. The yard was a very high quality operation and they have been very stand up in dealing with this. This was a failure of a subcontractor and one I am confident the yard will deal with.

Any information would be appreciated.
Ben

Use toilet cleaning acid like 'The Works" or similar-- it is a great rust remover might put paper towels over the rust area then pour and spread the acid on it--let stand for 20-30 minutes then remove paper towels and wash acid off.

[Suijin]

Not sure what is in Mary Kate On&Off but it takes out rust stains very well, but it is relatively expensive. That said, if the metal particles are embedded in the gelcoat the rust is going to keep coming back.

[UNCIVILIZED]

Hot steel particles landing on plastic (gelcoat) = embeded metal, to include some of it being bonded in place due to the gelcoat's melting around pieces of it when it landed. So, no fixes from my perspective.

[ziacek]

Oxalic acid is the best (and cheapest) rust stain cleaner. It comes in powder form so you would dilute about 100 grams in 1 litre of water, spray the solution on the contaminated surface, agitate with a soft sponge and rinse with water, polish afterwards. Oxalic acid is an organic acid and is safe to use on usual materials found on boats. That said, if the metal shavings are indeed embedded in the material then the oxalic acid will not dissolve them easily.

[Captain Bill]

I use phosphoric acid to remove rust stains which I have in copious amounts due to crap anchor chain. The problem you have is that it only removes the rust not the metal particle that released the rust. If the metal is well embedded in the gel coat I think that you'll just need to keep repeating the process until all the metal has turned to rust. Unfortunately this may take some time. Salt water wash downs might speed up the process.

[senormechanico]

Agree with the above.
How about a good hard pressure wash to knock out as many as possible of the embedded bits, followed up with the Ospho/phosphoric acid treatment?

[barnakiel]

We had a similar problem here with metallic dust blown of a high wall onto our deck. It was only a problem for about 5 years. I think when the particles are very small, the problem only lasts till all the metal rusts away.

Interim we brushed the deck and used small amounts of rust cleaning stuff tooth-brushed locally. But the marks re-appeared as soon as there was any humidity/salt present.

You may be forced to simply live with it.

Cheers,
b.

[toodleoo]

Probably not so much what he was grinding but the fact that he was using a ferrous grinding wheel,.

[minaret]

There's no fix short of painting it. I was involved in a local case wherein a contractor working for the state on a local bridge did the same thing to most of an entire marina which was below the bridge. They lost in court and we painted a couple dozen vessels. Make them make it right.

[Dymaxion]

Try Coca-Cola, it's loaded with phosphoric acid. Cleans rust off old chromed car bumpers rapidly. Let it soak overnight if stubborn. Not going to dissolve big particles that have melted in as others have mentioned.

[rwidman]

If you are expecting payment from the contractor or his insurance company you probably shouldn't be sanding the boat.

That said, any of the acid based rust removers that's labeled as safe for fiberglass could be tried. Perhaps you're not leaving them on the surface long enough.