Join Date: Oct 2006
Thanked 4 Times in 2 Posts
Rep Power: 9
Orange spots on deck - sunscreen
I recently noticed my boat was developing odd orange spots here and there, mostly smeared looking areas and a few spots that looked like drips. There seemed to be no rhyme or reason for the placement of the spots, except that they were primarily around the cockpit.
The culprit turned out to be sunscreen. The ingredient avobenzone (aka Parsol 1789 and other names) reacts with iron in water, causing rust stains. That explains why the spots seemed to appear out of nowhere - the sunscreen smear had to get wet to turn orange. The same effect can occur on clothing, with areas that touch sunscreen, such as collars, turning orange when exposed to iron in the water when washed.
This may be old news, but I have never had this problem before. Avobenzone is becoming a much more common ingredient in sunscreen in the US.
At least I know how to get rid of those ugly orange spots now.