Petaluma, CA - Brown Stains on Deck

[FlyWright]

I went to Petaluma last week and the all boats tied to the dock downtown found brown spots on our decks apparently from something falling onto the boats. I have tried Simple Green, Bon Ami, Acetone, Hull Cleaner and oxalic acod/wood bleach. None remove the stain but the abrasion of the Bon Ami lightens it slightly and the oxalic acid leaves lightened patches of non-skid but does little to lighten the stain.

I left a message for one of our resident TFers, mfreeman1998, who is a member of the Petaluma YC hoping he's heard of this and knows of a solution. In the meantime, does anyone here recognize these stains? Any suggestions for removing them without discoloring the underlying non-skid?

I suppose one option is to allow them to fade over time in the sun, but I kind of have my doubt that this will be effective.

Thanks in advance for any and all assistance.

 

[Yahoo 1]

I went to Petaluma last week and the all boats tied to the dock downtown found brown spots on our decks apparently from something falling onto the boats. I have tried Simple Green, Bon Ami, Acetone, Hull Cleaner and oxalic acod/wood bleach. None remove the stain but the abrasion of the Bon Ami lightens it slightly and the oxalic acid leaves lightened patches of non-skid but does little to lighten the stain.

I left a message for one of our resident TFers, mfreeman1998, who is a member of the Petaluma YC hoping he's heard of this and knows of a solution. In the meantime, does anyone here recognize these stains? Any suggestions for removing them without discoloring the underlying non-skid?

I suppose one option is to allow them to fade over time in the sun, but I kind of have my doubt that this will be effective.

Thanks in advance for any and all assistance.

Are they rust / iron stains ? If yes, try 10 or 20-volume peroxide which is safe for your boat. Then rinse with clear water.

 

[Yahoo 1]

Rectification:
I forwarded your pics to a chemist who is working for my company. He said this could come from a kerosene, or more aggressive fuel, or hydraulic oil (brake fluid is very aggressive as well) vapor purging or leaking from a plane.
First at all the stains effectively should be identified, if possible.
Peroxide should be tried.

 

[Gmarr]

Are they aerial spraying for medfly or anything like that? When I lived in CA that resembled the spots we would get with the malathion spraying in the late 70s

 

[FlyWright]

I forgot to mention that after my first attempt against the stains using a hose and boat brush, I tried my electric pressure washer on the gray nonskid and white gelcoat. Both attempts were useless.

Thanks for the ideas. It's not rust and there was no aerial spraying. It's blotchy in areas and not uniformly covering the bow. Nothing on the side decks or cockpit.

Since Giggitoni was with me in Petaluma and we berth at the same marina, I went over to Ray's boat to climb aboard to see how his looks. Ray told me his boat detailer was due to be cleaning his boat this week but I didn't see him so I went to the bow. It was very clean and had apparently been cleaned very recently, so I started texting Ray when his guy came around the corner as surprised to see me as I was to see him. In this case, the recent cleaning was just moments ago!

As it turns out, he found Ray's horizontal gelcoat surfaces with plenty of spots but his teak decks showed nothing. (Score one for teak decks!) He had to buff it off with a West Marine cleaner and wax combo product. There were a couple little areas he was still working on getting clean, but the boat looked great.

He's of the opinion that they were little bugs like mosquitoes. We had no mosquitoes in Petaluma but they could possible be small bugs that landed and died or drowned in the dew, then dried into the deck. Died and dried, as they say! We had a perfectly dry ride home that day in mill pond conditions and were running late, so I decided to wash the boat a couple days later when I returned for routine mx. In that time, they seem to have grown and darkened. Maybe it's some sort of protein deposit that feeds an algae or fungus. In light of that, he thinks a bleach solution that can sit on the deck for a short period might be the best way to proceed.

Pilou, I will attempt a small area with the peroxide you suggest. Hydrogen peroxide, right? (Don't want to get the wrong kind...)

Mechanical scrubbing ain't my thing and I can't buff the non-skid very effectively. I'm open to suggestions from anyone, but especially from those who have experience with bleach or peroxide solutions on gelcoat/non-skid. It's light gray non-aggressive non-skid.

If all else fails, I'd be fine letting it set for the fishing season because time cures all wounds...including bug spots on boat decks. Sometimes, when I'm feeling lazy, it's nice to have a fishing/cruising boat that can get messy and lacks a certain genteel finish. With a boat like this, overly waxing and scrubbing is like putting lipstick on a pig.

 

[BruceK]

Is it staining or has something eaten into the paint finish?

 

[markpierce]

Gee whiz. Been to Petaluma at least three occasions, and at least twice with FlyWright, without the problem.

 

[markpierce]

Hopefully, Petaluma YC membes can provide a solution.

 

[FlyWright]

Another thought came to mind this evening talking to Ray. There are restaurants nearby including a nice steakhouse. Maybe one of them blew out their smokestack with a good flameup and sent chimney debris into the air. Seem plausible?

 

[sdowney717]

Try using chlorine bleach.

Bleach or no Bleach?? - The Hull Truth - Boating and Fishing Forum

 

[Yahoo 1]

Al,

Thanks for additional informations based on your surrounding observations.

From my humble professional experience :

- Most of flying insects are attracted so irresistibly by white / very clear / bright surfaces which would suggest why plenty of spots on gelcoat surfaces but teak decks of Ray's GB 42' showed nothing.

- I don't think chimney debris into the air from steakhouse restaurants could leave permanent marks for the reason vegetable oils and animal fats absorb oxygen from air when heated then are totally burning between 125 F (butter) to 420 F (olive oil) releasing less or more dark smoke which dissipate into the air free of debris of that size. Moreover any cleaning agent effortlessly removes burned dirt and fat or oil marks which was not the case with you.

- Bleach solution only at low concentration, (behave of chlorine, bleach solution is sodium hypochlorite which may attack the shine of gelcoat or paint) improved by the sun (the "best friend" of bleach solution) should be tested.

- In this particular case my preference would be hydrogen peroxide due to its properties, notably its lack of harmful gelcoat effects, in weight of 10 to 20-volume.
Hydrogen peroxide in weight of 10-volume is prescribed / dispensed by dentists as a disinfecting, oxygenating, solution in mouthwash with a positive effect on more radiant teeth whitening. All the teeth whitening products you can buy there at Costco, Walmart, Target, CVS, Walgreens etc.. are using a light activated compound and a large concentration of peroxide based gel so therefore peroxide is safe for your deck.

- I would try a weight of 20-volume peroxide which I would first dilute with 50% of clear water (to get a 10-volume) then try it, applied with a cotton ball by pressing on the stains, then increase the concentration of peroxide up to 20-volume depending on the results. Problem is hydrogen peroxide is more expensive than bleach solution therefore bleach solution could be fine, once again in low concentration.

- I would like to take advantage of this opportunity to say that 20-volume peroxide is the best way to whitening a wood deteriorated by humidity action showing dark or black stains. Lately I helped a friend of mine to "whitening" the inside of his boat's door badly humidity stained. We sanded the wood, applied 20-volume peroxide, then we let it take effect for a short time (1 hour). Attached pics are showing Before and After (not re-varnished yet on the pic).

 

[Steve]

Spiders eat bugs and cr@p India ink could they be the cause?

 

[KneeDeep]

I just used Slimy Grimy for the first time and it did it great job on some problem rust stains on our non-skid. Did not appear to discolor. Used with hot water per directions and had to reapply a few time but eventually all the stains were gone. Anyone familiar with what's in the stuff?

 

[captgrail]

FlyWright - interesting. I had a similar thing as well as a neighbor just last week. The other possibility is the Pelicans are starting to show up here in numbers - maybe droppings? Lord knows what they eat and digest seems like india ink bombs sometimes but between them and the barn swallows I've brought all sorts of cleaners. We are in the flight path of SFO so I'm thinking it could be something getting dumped from the planes. We have tried multiple products but nothing including bleach would touch it. My stain was on non skid and I just happened to think if it was somehow rust I tried some Collinite's No.850 Metal Wax - it's a non abrasive cleaner/wax and no harsh chemicals but it took it up right away with a scrub brush. Whew!

He wasn't as lucky but it was a smooth surface. I'll mention the peroxide to him. Very impressive before and after on the wood - thanks for sharing that tip Pilou. I did finally figure out how to outsmart the barn swallows though I put split plastic corrugated tubing (meant for organizing wires) on my mast rigging where they loved to perch and created a skunk stripe on my deck and it works perfectly! Cheaper than some new exotic cleaner and a lot less work. The little buggers won't land on it. Better than a bunch of DVD's flying around to "scare' them off which never really worked that well.

 

[Art]

Vulture crap can be very acidic... depending on factors of their diet. It can eat through auto paint to the metal/plastic. You may have had droppings splatter across your deck.

 

[MVDarlin]

Oxalic acid can work miracles. You can buy at Ace hardware in granular form. It is known as wood bleach.

 

[FlyWright]

Thanks, Darlin! I have some onboard and used it to no avail. I also purchased some mold and mildew spray through Home Depotcontaining bleach and it seems to have helped in the test areas.

I put off treating the entire area due to my own laziness and other higher priorities. Nature has taken its toll on the stains now and they are very pale and becoming much less noticeable. Now that I've moved the dingy onto the foredeck for the fishing season, most of the spots are covered by the dink. Hopefully, when I reposition the dink in the spring, all will be gone!!

 

[ancora]

We had a slip some time ago, in Redondo Beach, Kalifornia, adjacent to a gen plant. They would "blow" the stacks at night when no one was around leavin' hard to remove spots on the boats in the marina.

 

[FlyWright]

The powerplant in Pittsburg paid our friend Dswizzler $75/month to wash his boat, located downwind from the plant. He joked that used to pay his kid $50 and pocket the rest!

 

[rwidman]

I have had bug stains on my boat in Florida that wouldn't wash or compound away. Acid hull cleaner didn't work either. I decided I would just have to deal with it when I got home. By the time I got home (3 weeks or so) they were gone.


If acid based hull cleaner or acetone won't remove them I suggest waiting to see if they fade by themselves. I wouldn't use anything abrasive on gelcoat ot non-skid.

 

[fryedaze]

Try this. Oxalic Acid and Hydrofluoric Acid. It cures a lot of stains. You can use it full strength but I usually dilute 50/50 because you don't need full strength.

 

[DavidM]

This season, because I kept my boat on a mooring out in the Connecticut River, I had bird ****, crab and fish carcasses and who know what else caked on my cabin top. I tried Barnacle Buster, TSP, Bartenders Friend, MEK solvent and lots of others. Nothing would cut the hard polymer type residue that was caked on top.


So I just left it for the sun to work on. A month later (after I got away from the birds) it was gone. Mother Nature can work miracles.


David