Little Red Spots on Deck

[Intentional Drifter]

I've been cleaning the boat after 4 weeks in the boat yard, mostly inside but some outside. I'm seeing lots of small (1mm to 2 mm) red spots on the deck. No particular pattern. Most of them are an irregular star-like shape.

I'm having no success in getting them out. I've tried boat wash, non-skid cleaner, black streak remover, and Fiberglass Stain Remover (the oxalic acid in a gel stuff). No luck with any of them.

I haven't tried compound, as they're all over including on the non-skid. I'd rather not have to compound the entire 44' X 23' deck, which doesn't otherwise need it, anyway.

Any suggestions, anybody? Any idea what this is (sorry, I don't have a pic)?

Thanks!

ID

P.S. And a big Hello to Kashmir Cat, who stopped by the boat today just to chat. Great meeting you, KC!

[FrankZ]

Berries mayhaps? Some bird leaving them behind?

[bewitched]

Rust?

Anyone been using an angle grinder in the boatyard?

[Intentional Drifter]

Originally Posted by FrankZ

Berries mayhaps? Some bird leaving them behind?

Don't think so. Don't look at all like bird poop -- way too small and there's nothing else there. Also, they're flat.

What I initially thought was very small iron filings that rusted. But, rust remover doesn't touch it.

ID

[Chief Engineer]

Berry interesting.......

I get that at certain times of the year....at my home.....it's something starling eat....

[Chief Engineer]

Was there any sand blasting going on?

Or Soda Blasting?

Airborne bottom paint?

[senormechanico]

Have you tried bleach?

[Hud3]

Originally Posted by Chief Engineer

Was there any sand blasting going on?

Or Soda Blasting?

Airborne bottom paint?

Paint is the first thing that came to mind. Any red boats nearby?

[Hydra]

I have had the same kind of little red spots on my deck. Since my yacht is on a mooring buoy, it couldn't be rust or paint.

It was soya dust from freighters on the other side of the harbor! When they unload, a big cloud of yellow dust drifts on the town or on the harbor, depending on the wind, and settles everywhere . After a while, each speck of dust turned red as rust.

And later, it provided a starting point for lichen, that I removed with white vinegar and brushing.

Alain

[barnakiel]

Rust never sleeps. Can be small pieces of metal (from filing or grinding on yours or neighbouring boats) they are minute and when they start rusting they leave marks just like you have described.

b.

[Lodesman]

Might be spider poop (?)

[Charlie]

How long did you leave the FSR on for. It sounds like rust to me. I just used the FSR product and was most impressed. I leave it on for somewhere between two and twenty minutes and it clears up the rust stains.

[sandy daugherty]

The star shape is highly suggestive of paint overspray. Try a pocket microscope and see if it looks drops of candlewax enlarged, kind of rounded over at the edges. Stains will likely appear to be partly beneath the surface of the gel coat. Don't worry about all the tiny pores that appear under high magnification; that's what gelcoat looks like!

With just a 2 or 4x magnifying glass, see if you can pry up a spot with a fine pointed tool. If you can, it's paint. Somebody dun you wrong.

[Intentional Drifter]

Might it be rust? Definite possibility. It has been in a rather large boat yard and outside much of that time.

Sandblasting? While not at this specific facility, there's lots of work going on with various boats in the surrounding 100 yards and I have no doubt there's been some blasting happen.

Airborne bottom paint? I sort of doubt it -- the spots are quite irregular in shape. Some are almost a line, others star-shape, others, just a dot. They vary in size from less than 1mm up to around 2 mm at the largest. The color is not bottom paint red, more orange in it.

Spider poop? Wouldn't that wash off fairly easily?

RE: paint overspray -- I'll take a magnifying glass and take a close look at it. Thanks for the tip. But, wouldn't the MEK pretty much take that off? It didn't touch it, even when left on for 15 to 20 minutes.

I have not tried bleach, but will do so.

Regarding the FSR, I left it on for up to around 20 to 30 minutes. However, it was cool and misty day, so I have no doubt that it got diluted some. I'll try it again tomorrow or the next day when the weather is supposed to be drier.

Another friend suggested Soft Scrub, which is a different mild acid.

I think I'll grid off a few sections and do a little experiment. I'll report back.

Thanks for your suggestions. If there's any more, please keep 'em coming!

ID

[hellosailor]

"Another friend suggested Soft Scrub, which is a different mild acid"
Actually it is a mild abrasive, like BonAmi, whch is generally safe to use on plastics. Some of it has simple bleach added, the original flavor doesn't. If you have old fashioned Crest toothpaste, that also has the same abrasive in it and makes a good mild polish. Diatomaceous earth, aka Fuller's earth, safe to use on glass and plastics.