Part of what makes King Starboard such a versatile material for fabrication of all kinds of marine parts and accessories is the fact that it is impervious to UV, moisture and salt. Unlike gelcoated fiberglass, steel, aluminum, wood and other materials, Starboard will never fade, never rot, never corrode and never delaminate.

Unfortunately, there’s also a lot that Starboard isn’t impervious to: fish blood, muddy shoes, greasy fingerprints, coffee splatters , Cheeto goo, wet leaves, rust stains, scuff marks from dark soles, and the aerosol sunscreen your brother-in-law soaks his kids in the second they step on the boat. All of those things — and more — will leave marks or stains on King Starboard surfaces just like they do on your gelcoat and upholstery.


Cleaning Starboard

The good news is that you have lots of options for cleaning Starboard. Because it is very resistant to chemicals, only the harshest acids and solvents will harm the surface. DO NOT clean with methyl ethyl ketone (MEK), turpentine or naphtha salvent.

Short of that, many marine, household and shop cleaners are safe to use on Starboard and effective on different kinds of stains. Of course, it’s always smart to start with milder cleaners and progress to harsher options only if needed.

Here are effective materials and methods for cleaning common stains:

Day-To-Day Grime

For anything that doesn’t come off with your normal end-of-day washdown routine, try SoftScrub Cleanser with Bleach or a similar product with a stiff brush or a nylon pot scrubbing pad. Don’t scrub too hard;

Soft Scrub is a mild abrasive, and it’s possible to damage Starboard’s matte finish with excessive pressure.

SoftScrub with Bleach cleaner for efficient starboard cleaning

Be sure to rinse thoroughly too. Soft Scrub only contains about 1% bleach, so it’s a minor concern, but the fact remains that bleach can corrode metals, strip away wax and eat at some fibers.

Alternatively, pressure washing won’t hurt Starboard and removes most minor stains quickly.

Tougher Stains 

When Soft Scrub and pressure washing aren’t effective, it’s time to move to more aggressive chemicals and abrasives.

Goof Off and Simple Green are more powerful cleaners that are safe on Starboard and effective against a wide variety of stains.

Simple Green cleaner removing dirt from king starboard

Magic Eraser pads and similar products are very effective on Starboard, but keep in mind that they work much like cutting compounds work on gelcoat, actually removing a thin layer of material. That can affect the “sheen” of Starboard, so be careful and err on the side of caution.

Organic Stains

For organic stains — particularly fish blood and the stains left by leaves and other tree debris — bleach is an almost sure-fire fix. Mix it in a 1:1 ratio with water and apply sparingly to the stain with a spray bottle. Wait a couple of minutes and rinse very thoroughly with water.

Again, bleach isn’t good for your wax coat, your metal, your trailer or even your yard. Don’t use more than you need and flush everything completely after use.

Goof Off and Simple Green are more powerful cleaners that are safe on Starboard and effective against a wide variety of stains...Magic Eraser pads and similar products are very effective on Starboard, but keep in mind that they work much like cutting compounds work on gelcoat, actually removing a thin layer of material.


Rust stains are tough to get out of Starboard. Your best bet is an acid cleaner. The first one to try is the household cleaner Barkeeper’s Friend, which contains oxalic acid. Try making a paste from the powder cleaner and water and letting it sit on the rust stain for several minutes. 

No need to scrub; acid cleans rust stains chemically.

Whink Rust Stain Remover (the liquid, not the spray), which contains hydrofluoric acid, is also effective. Finally, muriatic acid, commonly used in swimming pools, can also be used, but it is highly caustic and dangerous in its undiluted form and should be considered a last resort.

Oil And Grease

For oily stains from greasy fingers or shoes, try a citrus cleaner like ZEP Heavy-Duty Citrus Cleaner, denatured alcohol or mineral spirits. If none of those work, try spraying the stain with WD-40, then scrubbing with toluene or acetone.

Don’t use a colored brush or scrubber. Acetone and toluene are powerful solvents; use sparingly and then rinse and clean the area thoroughly when done.


If you splash gasoline on your Starboard at the gas station or fuel dock, wash the area as soon as possible with dish soap and water, then rinse with clear water.

When All Else Fails…

When absolutely nothing else works, you can always sand a stain out of your Starboard. Be aware, though, that this will remove the material’s matte finish and leave a different-textured area. Work slowly and carefully.

A Layer of Protection

For Starboard surfaces that you don’t walk on, applying a protectant like Armor-All, 303 or Pledge furniture polish can add a luster to the finish and help hide small surface blemishes and imperfections.

Don’t use these products on walking surfaces, though, as they can make Starboard slippery.

Starboard Don’ts

When marking Starboard for cutting or drilling, DO NOT use a pencil, pen or marker directly on the material. Removing these marks is particularly difficult.

Instead, either tape over the surface with painter’s tape and make your marks on the tape, or use a grease pencil (also known as a China marker or wax pencil).

The Power of Sunshine

One last word about keeping your Starboard clean: many boat owners underestimate the power of good old UV radiation — aka sunlight — and time as stain removers.

The fact is that many stains, especially the orange stains from aerosol sunscreen, slowly fade and disappear with time and sun. You may or may not want to wait for that to happen, but it’s certainly something to keep in mind before taking aggressive measures like sanding.

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