How to remove black spots from non-skid

[davjonLegend]

Over the winter, black spots (mold?) have appeared/grown on the non-skid of my 1993 37.5 Legend. Scrubbing with a stiff brush (plastic bristles) has removed some of it, but I can't get to all of the spots. (They are down in the crevices of the non-skid.) Washing with my power washer started to remove some non-skid, so stopped that.
Is there a safe method or chemical to remove/kill the black spots?

 

[Steve Dion]

Try totally Awesom. You can get it from the dollar store, $1.00 / bottle. It does good job.

 

[Ken Prichard]

We use Tilex shower and tub cleaner.. It's made to remove mold and that's what the black spots are. In our marina it's pretty much what everyone uses.
Cheap, easy and available anywhere.

 

[todd brown]

I power washed my ODay 222 yesterday. Water only. Must be very careful around fittings but sure beats a day with soft scrub and a brush.

 

[Forrest15112]

I used the method shown in this video. Mine was getting chalky from using tilex and other bleach on it. I followed up with some Woody Wax. I'm not super impressed with the Woody Wax, but it lasts about a month and isn't slick - especially when wet. The carpet brush on the buffer using some compound worked great and removed all stains and left the non skid looking new.

 

[davjonLegend]

Thanks all. Since I've tried both ends of the spectrum (hand brush alone and power wash), I'll start with least aggressive and work up -- Steve's $1 cleaner (bought it this afternoon), then Tilex, and then compounding. Will report back in a week or so.

 

[Alctel]

Please do - I have the same issue.

 

[davjonLegend]

Here's my latest results -- Washed the deck with fresh water, then sprayed Totally Awesome on each spot and scrubbed (plastic bristle brush). It foamed up, and some mold spots removed, but still not great. Steve, how do you apply it?

Then started again and splashed a bit of Clorox bleach on each spot, and scrubbed (with gloves). Took off more spots, but some still there.
Next week I will try a bit of Tilex just to compare. (Didn't have it with me.)

So far, I think the vigorous scrubbing is having the primary effect. And a bit of foaming from the cleaners probably helps. But basically, the black spots that remain just seem to be tucked in o the crevices of the non-skid surfaces, making it impossible to get a brush directly on each of them. I may buy a different brush to see how that works.

To keep ahead of this in the future, I suspect I just need to be more consistent about washing with a mixture of boat soap and a bit of bleach to discourage new growth.

I'll report back how the Tilex works out. Can't wait to get back on my hands and knees with that scrub brush again!

 

[Steve Dion]

I would try the Totally Awesome without wetting the decks first. Let it sit for several minutes and scrub with a stiff brush.

I have no idea what is in this stuff, but my friend said it removed varnish off his cabin sole.

You may also think about Simple Green. It works on certain types of grime. If the above does not work then there is always oxalic acid. You can purchase this cheap on ebay (not the diluted stuff that they use for deck cleaner).

Bleach does not do much for cleaning. It will remove some stains but not much of a "cleaner".

 

[Cobra]

Until this year I'd never pressure washed my bote. I loaded the Honda powered pressure washer up and took it over last Saturday. Mixed Zep Industrial cleaner 50/50 with water in a garden sprayer and wet the entire deck down then pressure washed it. Clean As New. I've scrubbed my deck for Years but never again. It was 5x faster to pressure wash it. I had some areas that never came clean using a brush because you couldn't get to it.

I've also used Awesome, Comet, Simple Green, Greased Lightening along with Clorox before, the results are not the same and easier.

 

[Terry in Naples]

A local boat dealer here told me to use acetone on black scruff spots and it took them right off. ( like bumping a rubber dock molding strip or another boats rub rail). It even removed shoe scruffs. I use it then water wash any access off. It works for me.

 

[kloudie1]

As Mcathcart, i had never pressure washed my boat. I saw this on sale for around $70 and bought one. http://www.harborfreight.com/1650-psi-pressure-washer-with-auto-stop-69488.html
It did a really great job on the decks and non-skid; much quicker and cleaner and longer lasting than a brush/sponge/mop wash. A caution when pressure washing is to stay away from any sealants around ports and not directly on bedding materials.. The HP water can cut through, leaving a leaking place!

 

[Cobra]

As Mcathcart, i had never pressure washed my boat. I saw this on sale for around $70 and bought one. http://www.harborfreight.com/1650-psi-pressure-washer-with-auto-stop-69488.html
It did a really great job on the decks and non-skid; much quicker and cleaner and longer lasting than a brush/sponge/mop wash. A caution when pressure washing is to stay away from any sealants around ports and not directly on bedding materials.. The HP water can cut through, leaving a leaking place!

Amen! Cleaned cracks that I couldn't and works like a Champ on anchor chains. $70.00 is cheap too!

:+1:

 

[davjonLegend]

Just to clarify -- I power wash my plain flat surfaces and metal toe rails once a year. It does quick work of the green stuff, dirt in tight areas, etc. But I wound up blasting off the light gray paint from my non-skid areas, so stopped doing that. Which is why I asked about cleaners, wanting something that won't hurt the gray paint on the non-skid deck.

Latest result -- sprayed Totally Awesome directly on the black spots (no water), and let it sit about 10 minutes. It started turning to orange, which concerned me that a chemical reaction may be happening with the paint. Immediately flushed with lots of water, with no apparent damage to the paint. But the orange color change puts me off from leaving Totally Awesome on the surface for very long. Unfortunately, the black spots seemed to shrug it off. No change.

Next tried Comet powder on other spots, added a little water to form a paste. Let sit for a minute. Scrubbed off with brush. Some spots came off, some didn't. I still think its mainly the mechanical brushing that is having the most effect.

Still didn't have Tilex available. And the weather was turning nasty. So quit for the weekend. Still on the look out for that miracle cure. As I have learned over many years, one sailor's cure may not work for every case. But I'm not giving up, so keep sending ideas. I just remind myself that even scrubbing the deck on my boat has curative power to my mental state.

Thanks everyone. When I posted this mundane question, I didn't expect any answers at all. Nice to have an active group to learn/share with.

 

[kloudie1]

A caution about chlorine based cleaners (Tilex, Comet, bleach etc.) on sailboat decks.. If it gets into a swedged rigging wire socket and is not rinsed out thoroughly, it can cause cracking in the stainless swedge.. Just be careful not to splash the cleaner on anything stainless where it can't be thoroughly rinsed.

 

[ariasca]

So I am a bit concerned that there is little consideration for the environment in this discussion. The products and chemicals suggested are not suitable for washing overboard and into the delicate ecosystem of our water ways. Most of the chemicals listed are highly carcinogenic, bleach and phosphates are particularly damaging to our water system. (http://water.epa.gov/type/rsl/monitoring/vms56.cfm). A power washer is great, vinegar is also good for cleaning decks, if you need an abrasive, use baking soda.

Here is a rule of thumb, if you cant eat or drink it, then don't put it in the water.

 

[davjonLegend]

For the sake of saying it, the amounts I use are very tiny and localized to the black dots of mold. Compared to what people put down their drains and into the sewers at home (which reaches the rivers and bays), this is insignificant.
Nevertheless, thanks for the environmental concerns. It's good advice for everyone to keep in mind.