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How to Renew VS721 Foul Release Coating


Ryan Vale asked:

we got a brand-new Rinker (37 ft) last year and dealer put VS721 on before boat was delivered. We just cleaned the hull and it is back to factory color. No residue or stains.

Can we just put another coat of the VS721 back on? Or do you need to prep it with something?




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T prep the surface before applying VS721, scrub the bottom with Boat Scrub and a Marine Power Mitt. Rinse well and allow it to dry. This will remove any pollutants and oxidized VS721 that can prevent proper adhesion of the new coat of  VS721.

Apply VS721 with a large damp sponge, rubbing it in well. After it hazes up, wipe off the haze with a soft cloth such as a terry towel, microfiber cloth or old T shirt. If the ambient temperature is above 70°F and relative humidity below 50% wipe off the haze within 20 to 30 minutes. If the ambient temperature is below 70°F, but above 50°F and relative humidity above 50% wipe off the haze within 45 to 60 minutes.

Allow to cure a minimum 24 hours and apply a 2nd coat of VS721 as above. Allow to cure a minimum of 48 hours before launching your boat.

In addition to the hull, apply VS721 to all surfaces below the waterline, including the lower units of the stern drive, trim tables, transducers, etc., paying special attention to hinges and brackets. This will reduce fouling and eliminate the attachment of Zebra Mussels. Also use a bottle brush to get the VS721 up into water intakes and remove the water intake plates on the stern drive, make sure they are free of zebra mussels or other fouling, and apply VS721 with a small bottle brush. Water intakes are often missed when cleaning at the end of the season and if Zebra mussels lodge in that area, they can block or reduce the cooling water to the motor and cause overheating.

Regular, proper, application of VS721 is important for the protection of your boat bottom. In addition to the reduction of fouling attachment and staining, ease of clean up at the end of the season and better performance and less fuel consumption it also seals the pores in the gel-coat to protect against water migration through the gel-coat with resulting osmosis blistering. It’s very cheap insurance. Blister repair can be very expensive and osmosis blisters will devalue your boat.

If your dealer did the complete protection package on your new boat, he probably also protected the hull with Premium Boat Shine, the non-skid and smooth deck portions with Sure Step, the vinyl seats with Vinyl Guard and the canvas top and covers with Canvas Shield. These surfaces should also be cleaned and the protection renewed every spring to keep your boat looking new and reducing maintenance. Maintaining your boat in this way will ensure that you get maximum value for your boat when you sell or trade up in the future.


Thanks for your question,


Captain Aurora
Richard Kittar

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