greyish pink deposit on deck when boat is on terrain in winter

[thomashoebus]

When my boat is out of the water for the winter there is always a grey - pink deposit on deck which forms after 2 - 3 weeks on the terrain. Probably it has to do someting with pollution in the rain or so... because the deposit comes partly in the form of drops. I checked other boats on the terrain but they don't seem to heve this problem. It is very diffucult to clean the boat, i have to use a product (ship clean) with phosphoric acid to get the boat clean again from this depoit. Has anyone any idea of what this dirt is and where it comes from or how to prevent it. I don't have this problem when the boat is in the water. The problem is worse on the antislip parts of the boat. The deck is white when clean. The boat is a beneteau

 

[alan]

Can't help you with the pink stuff but I have the same thing with black deposits in winter .......... in the water. I am pretty sure that it comes from pollution in the rain. Lots of people here (Nettuno, Italy, with marina 100m from town) say it is oil-fired heating but I don't agree 'cause it starts in Octoberish long before anybody is even thinking about putting heating on! I think that here it is just traffic pollution; but in Italy you are not allowed to say that because "the car is King".

Do you have some chemical works/factory near you that could be causing it? Perhaps it is not the fact that you are out of the water but the fact that it is winter and it rains (more)???

 

[geoffatstanpit]

When I kept a boat on the Hamble I always got a grey with black spots deposit on the deck which was also the devil to get off.

We always put it down to Fawley oil refinery to windward.

Do you have an iron-ore handling jetty to windward or anything else throwing pink stuff around?

 

[thomashoebus]

Well I never have it in summer it always starts when the boat is out the water. In fact during the summer the boat is in a harbour in the centre of a town with a lot more pollution (i think) In winter the boat is on a terrain near a much smaller town and practically no big shipping. Even after nearly non stop rain in august this year there was no hint of the deposit. And my boat has a lot more deposit than the other boats on the terrain.

 

[thomashoebus]

Well there is a factory around wich recovers sand out the sea and sells it but i never saw some combustion of fuel or so out there Perhaps it is some kind of pollution in the recovered sand or so.
The sand falls from a transportband on big heaps.

 

[Searush]

[ QUOTE ]
Well there is a factory around wich recovers sand out the sea

[/ QUOTE ]
I suspect that is your answer, sand from the Sahara is blown for miles out to sea and I have read of dust clouds around the offshore African Islands. I would think that fine particles in the sand (silica?) may be reacting with (acid?) rain to affect your decks. But, as usual on Fora, this is just another uninformed opinion so treat it as you wish! /forums/images/graemlins/tongue.gif

 

[PuffTheMagicDragon]

[ QUOTE ]
.... sand from the Sahara is blown for miles out to sea and I have read of dust clouds around the offshore African Islands.

[/ QUOTE ]

That was indeed my first thought as it is not uncommon down here after some days of Sirocco wind (SE).

But then I realised that this guy is in belgium: not exactly close to the Sahara.

It could well be a similar problem though, with fines from the sand recovery factory becoming embedded in the deck. It is possible that the situation has become worse (as in sticking more firmly) if wax has been used at some time.

I'm in total agreement with your last comment /forums/images/graemlins/wink.gif

 

[alienzdive]

two other conditions not mentioned

Although not pink, I have seen evidence of diesel deposits blown down a valley from a bridge 2 miles away. We traced it back to diesel contamination for a client and found it only happened when the wind blew from that direction. So the contamination again may be from somthing some distance away.

Also another contamination is from the constant dust from the DIY, professional workers, maintaing boats on the hard stand. Constant dust etc. If this is true in your case, pink primers, sanding red boats, spraying red antifouls could all cause this.

I find my boat has blackish deposits which I put down to the marina being next to a main road and traffic pollution particularly in the rain and very difficult to remove.

Good luck

 

[Searush]

Worst of all is Weld Spatter on GRP due to thoughtless b*st*rds welding right next door without any protection. leave little black spots everywhere which cannot be removed as the are burnt into the gelcoat causing permanent damage. Worse still, the spots quickly revert to iron oxide leaving small rusty streaks all down the hull. I really appreciate that small addition to my boat some years ago which is still visible! Thank you to that anonymous welder in Penryhn Dock about 10 years ago.

 

[thalassa]

The Belgian Met office now and then do report sandy deposits from the Sahara in certain conditions in summer. In June, we had an instance of a rather massive yellowish deposit of pollen !
To return to the original post, I had isolated greyish spots (about 3 mm) too on the boat, very hard to remove, and if I didn't, they tended to grow, rather than multiply, over the weeks. In the end, I took a sample and put it under the microscope at home. It was a sort of tiny lychen. I sprayed the spots with roof algae remover, and they didn't return that season.