Hull paint questions and help plz

[DrGonzoMIA]

So started sanding down a few areas which appear to be causing me some leaks after the heavy rain recently. However I'm slightly confused by what I'm finding. There appears to be a metallic coating (which seems rusty) then a green coating, down to what looks like a red oxide primer and then bare steel. I can't figure out why there would be a metal top coat though?? Anyone have any answers at all ? I can only assume the top paint has some kind of metal in it ?

[Iain_S]

Someone been grinding nearby and not cleared up the steel dust?

[cuthound]

2 hours ago, Iain_S said:

Someone been grinding nearby and not cleared up the steel dust?

 

You could well be right. Back in the 80's I drove a Citroen BX, and the bonnets and tailgates of these cars were made of sheet moulding material (plastic).

 

A couple of weeks after returning from a canal holiday, I was somewhat surprised to find the bonnet of my car apparently going rusty, despite being made of plastic.

 

I guess the boatyard had been grinding nearby and tiny specks of hot steel dust had landed on the bonnet, burned into the paint and then slowly rusted away.

[DrGonzoMIA]

Yeah I had that on a Ford Ranger bonnet. Had apparently been used on railway work and sparks had sunk into bonnet and rusted. This just seems like a thin metal layer its bizarre. I'm just worried about stripping off this top layer if it's anything structural. If my steel is 5mm thick, by the time I've sanded this back it will be about 3 !?