Removing Yellow Stain from White Fiberglass

Skipper February 25, 2010 Ask The Skipper

Glen Allen asked:

I have a 10 year old white fibreglass boat and it now has a faint yellow tinge to the white hull….this boat is not left in the water.

Is this something that one of your products could return back to the original white?

Answer:

For your convenience, I’ve highlighted the hyperlinks. Click on the hyperlink to get more information about the selected product.

IN SUMMARY, to remove yellow stains from fiberglass, you have to:

Wash and clean the boat with a multi-purpose boat cleaner like Boat Clean Plus
Use a fiberglass cleaner and restorer like Boat Scrub to remove stains and yellowing of your fiber glass boat
We recommend using a Marine Power Mitt to reduce your labour and cleaning time
Add protection from UV and dirt to your fiber glass boat by applying Premium Boat Shine

IN MORE DETAIL:

This is a common occurrence resulting from the use of Boat Wax that contains Carnauba Wax. Many boat manufacturers now recommend that you do not use Carnauba Wax based products and only use synthetic products like Premium Boat Shine to protect your boat.

The best and easiest way to remove the yellowing and restore the original color and shine is with a 50/50 solution of Boat Clean Plus and Boat Scrub. This is what’s recommended by the boat manufacturers. Wash the boat first with a 1:10 solution of Boat Clean Plus and water and then use a soft cloth and the 50/50 solution to rub away the stain. You can use a Marine Power Mitt to reduce the labor required and the amount of time necessary to restore your boat.

Because of the age of your boat, the stain my have built up over the years and become indelible. If the above remedy does not work then the next solution is to wet sand the surface, followed by rubbing compound to remove the surface scratches and restore the shine, followed by Boat Scrub to remove the rubbing compound. This is pretty extreme because you will be cutting several layers of gelcoat off your boat, exposing the pores and making it more susceptible to environmental deterioration in the future.

Once a boat has been compounded or wet sanded you will probably have to detail the boat 2 to 4 times per year, depending on where you’re located and the ambient weather conditions, to maintain the finish. Compounding should be a remedy of last resort and should only be used if all else fails.

When the color and shine is restored protect your boat with Premium Boat Shine. It is synthetic so it will not yellow or stain and it will give you a diamond hard anti-static finish that will not get greasy or oily in the sun. Waxes tend to be greasy when warmed by the sun and this attracts and holds dust, dirt and pollutants against the surface. You will notice that Premium Boat Shine resists black streaks much better than wax. It is a combination sealer and polish and it contains some of the VS721 polymer for added durability. On boats in good condition, two coats on the hull will last a whole year even in South Florida.

Thanks for your question,
Captain Aurora