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Cleaning Non-skid Gelcoat Surfaces?


Feb 5, 2004
Tartan 3800 Westport, MA

My cockpit sole is textured gelcoat, a fine, sand-like texture. I can't pull the dirt out of it! I've tried washing it with "boat soap" and a brush, but I can't pull the black dirt out.

Any ideas?
Sep 25, 2008
Alden 50 Sarasota, Florida
It depends on what the “black” is. For normal accumulation of grime or dirt, most people who try a product sold at thrift stores such as The Dollar Store called “LA’s Totally Awesome” seem to think is the best. The marine store (read - overly expensive) equivalent would be RollOff.
Jul 5, 2011
Oday 28 Madison, CT
Black is often algae stains. Clorox Clean-up, a cleaner with modest bleach content can do wonders on this stuff. Spray on, let sit an hour and hose off.
Jun 25, 2004
Corsair F24 Mk1 003 San Francisco Bay, CA
After you get it clean, I recommend coating the nonskid with Woody Wax to help keep it clean. It seals the nonskid to repel dirt and stains, (Especially in the cockpit). It makes it easy to hose off dirt and spills with ordinary boat soap.

Woody Wax lasts about 2-3 months on my boat in harsh UV. How long it lasts depends to some degree on how frequently, Iuse the boat.

It’s very easy to apply and it isn’t slippery. It takes 10 minutes to WoodyWax the deck. You squirt some WoodyWax on, add some water, swish it around with a soft brush, and then rinse off until the water runs clear.

Two squirts does the whole cockpit including the seats. A single small bottle goes a very long way, more than a year on my trimaran.
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Likes: BigEasy
Jun 25, 2004
Corsair F24 Mk1 003 San Francisco Bay, CA
I use West Marine brand Hvy Duty Cleaner on the non skid for periodic deep cleanings. For monthly wash downs, I use West Marine Brand Boat Soap ( the pink stuff) . The pink boat soap doesn’t remove all the Woody Wax From the nonskid, and does a decent job of cleaning. That’s what several of the boat detailing companies who wash boats use. I hose off the boat thoroughly after every use, especially all the hardware. (We sail in salt water)

I buy the West Marine products during their annual BOGO sale, so the price is very reasonable. $30-$40 worth lasts me through 15-18 months of use. We sail year round.

For really tough yellowing and stains, I carefully apply MaryKote On & Off Gel, which is a very strong acid. Don’t get it on metal! I use it at the waterline too, for waterline stains. Don’t get it on bottom paint.

for rust stains on stainless and in gelcoat, I use Spotless Stainless, a citrus based passivating cleaner. The trick to that is to use it when it’s 70 F or warmer. Otherwise you have to do multiple applications and wait a long time.

I don’t use any abrasive products on the gelcoat, even Barkeepers Friend or Clorox Softscub. Too abrasive.
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Jul 1, 2010
Seaward 25, Catalina 350 Erie, Pa
For spring cleanup of the non skid, I've been pretty happy with Starbrite Deck cleaner (the Attwood stuff is the same thing). I then use have used Woody Wax, though this year I'm trying Starbrite non-skid wax. Seems to work as well or better than Woody Wax and costs less. For cleanup during the season I use Amazing Rolloff. It's truly amazing. A power boat guy turned me onto that stuff. It leaves it's own protectant behind. Also use it on boat cushions.
Jan 7, 2011
Oday 322 East Chicago, IN
I like Bar Keepers Friend powder for stubborn stains and cleaning....it has some oxallic acid in it I think. Some elbow grease and water usually get the fiberglass ( including non-skid areas) clean.



Feb 5, 2004
Tartan 3800 Westport, MA
Thanks everyone! I was able to clean up the black stuff with a chlorine-based kitchen spray and a brush. I think I have some Woody Wax for non-skid around somewhere.
Jul 15, 2020
Hunter 33 Dallas Corinthian Yacht Club
Glad you were able to get it cleaned up. I agree with the use of Clorox Cleanup. Have used it for years and it works wonders.


Feb 5, 2004
Tartan 3800 Westport, MA
I found the Woody Wax for Non-skid! (I don't know where anything is on this boat.) Years ago my son visited a friend in Florida, and it turns out the family owns Woody Wax. When they heard we had a boat they sent a gift bag/variety pack with probably every one of their products!

I'm going to wax the non-skid on deck and below, too, but I'm on a mooring and it requires a lot of water, so not today. When I do I'll report back.
May 25, 2020
Hunter Legend 375 Moss Landing
A friend of mine just turned me on to the west marine non skid cleaner with Teflon as well. It works pretty good for cleaning (definetly beats the boat soap, I use that in between and on the smooth stuff). The jury is still out on if the Teflon will make it easier to clean in the future. And the last resort if you want clean is the pressure washer, it will get all that junk out of the non skid.
Apr 2, 2018
Catalina 309 Morro Bay
I have found pressure washing to work very well on my boats non-skid. I also get the tough black stuff and found that scrubbing and brushing didn't cut it. I haven't had any problems with the pressure washing removing any of the non-skid, but I would recommend caution. On a side note I've found "Magic Erasers" to work really well on scuff marks on gel coat.
Jan 26, 2019
Catalina 30, mkI 2462 Waukegan, IL
What about oily types of stains? Who knows what they are from, maybe where I rested dollups of butyl tape when rebedding deck hardware, just general grease from oily rags, etc. I've used boat soap, non-skid cleaner, etc.
Jun 21, 2004
Beneteau 343 Slidell, LA
I have used Woody's wax in the past with nice results; will start using it again as I still have some on hand. It really seals the deck; therefore, bird droppings, etc are much easier to hose or brush clean. Its fairly expensive, so use it sparingly. Be careful when applying; the stuff is slick as ice while applying wet. Once it is applied, rinsed with water, and dries it isnt slippery any longer, even when re-wetted. So, strongly advise to not step on treated areas while applying; keep your footing on untreated areas and work in that manner/direction. You can really bust your tail; I'm talking feet sliding out from under you. Don't ask me how I have come to acquire this bit of knowledge! :facepalm:


Feb 5, 2004
Tartan 3800 Westport, MA
For what it's worth, the Woody Wax non-skid product I have is in a blue, aluminum can with a spray nozzle top. The instructions for use on non-skid are as follows:

Start with clean, WET decks. Spray 3-4 trigger pulls of WOODY WAX onto a soft deck brush and spread over deck area. (CAUTION: decks will become slick until rinsed.) USE WOOD WAX SPARINGLY. Allow water on decks to evaporate. THOROUGHLY rinse dried decks with heavy spray of fresh water removing excess wax. Dry decks with cotton towels.
(Emphasis in original.)

So, as I said, I'd need a lot of fresh water to do this, and at the mooring that's not practical, unless I just try a small section. Maybe the cockpit sole. Thanks, @BigEasy , for the caution about slipping! I will have to make a good plan to stay off the sole as I'm doing this, which could end up being like a bit of a circus act. :) And, in today's fog, nothing is going to evaporate!
Dec 27, 2012
Precision Precision 28 St Augustine
I’ve used Woody wax but prefer Starbrite deck wax. It’s applied basically the same as woody wax But I feel it lasts much longer. It comes in a spray bottle but is really to thick to be sprayed. I put it in a ketchup type squeeze bottle. Rinse the deck including non skid, squeeze a bit out of the bottle and brush it as if it was soap and water. I let it sit a bit and rinse it off. It leaves a Teflon coating that beads water and makes cleaning easy yet doesn’t make the deck slippery.