Many boat owners who leave their vessels in the water all season or all year in warmer climates use a non-toxic antifouling product called Propspeed to protect their protect their propellers, shafts, rudders, and other underwater metal from fouling with marine growth.
Conventional marine bottom paints do not adhere well to propellers and can promote corrosion and electrolysis on expensive bronze and stainless running gear.
Therefore, boat owners must turn to specifically-designed marine antifouling paints for props, and Propspeed, a non-toxic marine coating designed to make the metal surfaces too slick for barnacles and other marine growth to stick, has gained in popularity in recent years despite its high price tag (a 200ml kit costs $169.95 at several online retailers).
Distributor Propspeed USA claims Propspeed repels marine growth at least one year and up to two years, and can increase boat speed by up to three knots and reduce fuel consumption by up to 10 percent.
Owners say it generally works as advertised, although proper application is key to success with Propspeed. Propspeed USA recommends having a company-certified applier coat the prop, but skilled boat owners should have no problem tackling this project themselves.
Propspeed Marine Antifouling Application Starts with Clean Metal
In order for Propspeed to adhere properly, all metal must be absolutely clean and sanded with an 80-grit sandpaper, either using a soft pad with a power sander, or by hand-sanding areas impossible to reach with a power sander, according to Propspeed's application instructions. The company does not recommend use of sand-blasting, wire wheels or Scotch-Brite pads on the metal surfaces.
Once the metal is completely clean from old bottom paint coatings and the remnants of marine growth, Propspeed recommends washing the surface with water and then with its proprietary PropPrep Solution solvent. However, boat owners who fail to purchase the expensive PropPrep Solution ($99.95 for a half liter at West Marine) can substitute acetone or denatured alcohol.
In either case, the metal surface should be wiped with clean rags until the rags used show no sign of contamination.
Application of Propspeed Marine Paint Easiest with Prop Installed
Although sanding the prop might be easiest with it removed from the boat, actual application of Propspeed goes best with the prop installed and free to spin. In addition, two people apply Propspeed more efficiently than one.
Boat owners should not start the application process unless they can work continuously to complete it. Recommended application temperatures are 50 degrees to 100 degrees.
The first step is to open the etching primer can and stir the bright yellow etching primer with the flat-ended stick provided as part of the kit. The goal is to scrape and mix in all the solids that have settled to the can's bottom. Users must stir the can until the solids are dispersed, and then shake the can for at least two minutes in order to make sure it's properly blended.
Next, it's time to blend the primer base with the primer catalyst in a four-to-one ratio. If the entire kit isn't needed, it's possible to carefully measure four parts of base to one part of catalyst in a separate, clean container, and mix well. A 200ml Propspeed kit contains enough material to coat several props, especially smaller wheels.
Use foam brushes to apply the mixture. Although some areas may look blotchy as the primer dries, it's not necessary to go back and recoat them; Propspeed recommends one thin, uniform coat of the etching primer.
Clear Coat Follows Primer Quickly in Propspeed Application
The primer dries enough to be tack-free within about three minutes in warm temperatures and within about five minutes in cooler temperatures. Once the primer is tack-free, it's time to apply the clear coat.
Users should be careful to coat each propeller blade uniformly on both sides before moving to the next blade; it's not unusual for boat owners to find that they missed coating one entire side of a blade with either the primer or the clear coat.
If it's impossible to finish the application process for some reason, Propspeed says a boat owner can wipe the primer with acetone or denatured alcohol, recoat with the primer and then add the clear coat within seven days of the first primer application. After seven days, the primer will need to be sanded off and the process started over.
Propspeed Antifouling Offers at Least One Year of Protection
Boat owners who apply Propspeed according to directions should find their prop remains clear of marine growth for at least one year, the company says. Any growth that does appear can be wiped off by a diver, or will slide off while the boat is underway.
Propspeed is more expensive than other antifouling paints for props. However, boat owners have reported decent results with Propspeed, and many swear by it. For example, one owner found the product kept the prop clear for about two years while in warm Southern waters, while another saw some barnacles and other fouling, but not as much as expected, after three years at a dock on the Chesapeake Bay.
Proper application is key to making Propspeed work as advertised, but boaters who are accustomed to applying their own bottom paint or using two-part products should have no problem prepping and painting their own props with Propspeed.
Jane Anderson - Jane M. Anderson spends as much time as possible on the water, working and sailing on boats. She grew up sailing Sunfish and Rhodes 19s on ...
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